Trans Prog Failsafe when cool outside. Battery? VR? Alternator? (N62)
 

I've searched and read a bunch of TPF threads but haven't seen one that matches my situation exactly.

2004 4.4 with 41k miles, garaged. On a Battery Tender Jr when it's in the garage since it's driven once or twice a week. Battery is now a little over two years old. Garage is not heated.

Four or five times last winter, as soon as I shifted the X5 out of park or was about halfway down my block, and the temperature was in the forties or below, I got the TPF error along with the 4x4 warning light. I think the DSC light too, a couple of times. The temporary solution was to let the car warm up to about halfway to due north on the oil temperature gauge and then restart the car. The errors would then go away and everything worked normally. I'm in the Southwest, so it does not get below freezing often. No problems in the spring, summer or early fall.

Three drain and replace ATF procedures, twice in late summer and yesterday. The mechatronic sleeve, magnets, gasket, plugs and filter were changed on the last one. Last two changes we added about 6.5 quarts of ATF at 86 F fluid temperature after going through the gears, monitored on a Foxwell 520 Pro. The transmission shifts smoothly.

I got the TPF and 4x4 errors again two weeks ago when it was in the forties. Before starting the engine, the battery was at 12.2V. I used the Foxwell and set the Live Data to monitor the oil temp, gearbox oil temp, battery voltage and voltage at the transmission. Strangely, until the engine warmed up the voltage was 11.2 at both places. Once the engine was warm, both jumped to 14.1. I restarted the engine and everything was fine. No Service Engine Soon light.

I saved the codes from the Foxwell last time, but couldn't find the file with them on the microSD card when I put it in my PC. There were codes for the transmission, alternator and several other modules. My guess is that they're related to the low voltage.

Since the problem only happens when the temperature is colder, does it seem like a battery problem or is there something in the voltage regulator or alternator that would malfunction when it's colder outside?

Could well be a failing alternator (or rectifier/regulator on the back of the alternator. The symptoms fit.

You can monitor the voltage on the dash via hidden menu #7 (UBAT) while driving - if it gets below about 12.5-13v while moving, something is going to throw a fit - the trans in this case...

Thanks, wpoll. Voltage was definitely low 11.2 when the problem last happened. The odd thing to me is that it has only happened when it has been colder outside (under 10 C). Also, though my X5 just turned 16, I've only put on 41k, which seems low for needing a new alternator (not an expert on that!).

I look at monitoring the voltage via the dash. A little easier than hooking up the Foxwell.

I just got a new battery under warranty. Only $3 for the state fee. I'll update the thread if it turns out to be the VR / Alternator.

map sensor

Do you mean the MAF sensor? Would the TPF problem not appear all spring and summer? I wasn't aware that a MAF sensor issue only shows up when it's cooler outside (less than ~10 C).

So far, the problem hasn't reappeared since I replaced the battery on Wednesday. It hasn't been cold though.

EDIT: I read some threads on MAF problems. I don't have a Service Engine Soon light and no rough idle. I just tested starting the car and voltage was 12.1 in position 0, and fluctuated between 13.8 and 14.1 after I started the engine. It's about 65 F / ~18 C outside.

The MAP (Manifold Absolute Pressure) sensor is a totally different thing... and yes, our M57 diesel engines have both a MAF and a MAP. ;)

Thanks, wpoll. I have the 4.4i N62 engine. Do you think it could be the MAP? I haven't seen any codes for that yet.

Some colder nights this week, so I'll get to test to see if I get the TPF message with the new battery.

Thanks, wpoll. I have the 4.4i N62 engine. Do you think it could be the MAP sensor? I haven't seen any codes for that yet.

Some colder nights this week, so I'll get to test to see if I get the TPF message with the new battery.

Yeah, sorry - I know you have a 4.4 - my comment was directed at ad01, who also has an M57TU diesel.

I doubt this has anything to do with your MAF (Mass Air Flow) sensor. While it is known that MAF sensor issues can cause a change in trans shift behaviour (by design) I don't think it's common for this to be temperature related and certainly not to the point where a fail-safe condition is set.

You also specifically mention seeing low voltages from time to time, something that IS known to cause a fail-safe condition. I work on the principal that if you smell smoke, look for a fire (there are no coincidences...). ;)

Thanks for clarifying! I just got back from starting it when 48 F measured by the cluster after leaving the garage door open for 5 minutes, 42 F outside.

12.1-12.2 V on cluster before starting, it dipped to 11.2 briefly before gaining to 14 after about 15 seconds. Bounced around between 13.7 and 14.2 for the short jaunt I took it (mostly over 14). No errors or TPF displayed. It was on a Battery Tender Jr trickle charger, as is almost always the case in the garage for the last 16 years (replaced trickle charger at least once). I disconnect it before putting the key in position 1.

I'm a little concerned because this guy says the battery should read around 12.5 V before starting (even after leaving the high beams on for 5 minutes). What do you think?

Check the Battery Voltage in a BMW E39 E38 X5 E46 with high cluster
https://www.youtube.com/watch?v=z4Kk3Q5co5c


Here are the specs for the new battery (same model as the 2+ year one it replaced). New battery manufactured Sept 2019.

https://www.samsclub.com/p/duracell-...49/prod3590267

Specifications
Battery electrolyte composition: Acid
BCI group size: 49
CA at 32 degrees F: 1105
CCA at 0 degrees F: 900
DIN code:H8/L5
Freight class: 65
Polarity: Right positive
Reserve capacity: 185
Terminal type: DIN/SAE
Volts: 12

There's an AGM version of this battery which has fewer CA, CCA and less reserve capacity.

https://www.samsclub.com/p/auto-grou...ee/prod9510087

I'm using that battery in my E60 with no issues. Will get the same for the E53 when the current Oreilly's extreme bites the dust.

Thanks for the information. Are you using the AGM version? I saw someone was, in a battery thread I read recently. Not sure if it was your post.

EDIT: Not you: https://xoutpost.com/1121041-post18.html


If you get a chance, please post your cluster battery voltage reading before starting the engine in the E60.

I wouldn't think that the battery voltage is a problem. The only way to test it properly is with the car off, using a multi-meter on the jump terminal under the hood/bonnet. When you check the voltage via the car's hidden menu or OBD there is a significant electrical load on the battery - all the computer modules are awake, the fuel pump is running etc. It will read at least 0.5v lower than the no-load voltage, maybe more.

BUT, if it take 15 seconds for the alternator to start putting out a decent voltage after starting the car, I'd be worried. That's way too long - it should output the full 13.8-14.2v near-instantly. Sounds like the alternator or rectifier/regulator is on the way out - which could eventually kill your new battery.

Thanks. I'll check with a multi-meter tomorrow before getting in. I have the short cable for the trickle charger hooked up to the terminal under the bonnet, so I don't have to open it or the car door to measure.

It may have only been five to seven seconds for it to get to 14 V this morning. I'll time it tomorrow.

When it was warm on the weekend, it only took a second or two.

Bad news. It doesn't appear to be the battery. Late this morning, about 50 F outside, I got the 4x4 light and the voltage remained under 12 V for several minutes, finally climbing to 14. No other warning lights came on (no DSC, SES, etc).

After I let it warm up, restarting car fixed the problem. I didn't get the Trans Prog Failsafe error when I drove around. No problems after having the car in the sun after my lunch appointment or the two other shopping stops I made.

Here are the codes from my Foxwell:

Engine DDE Diesel Electronics DDE 3.0 (1):

28D7 / not present
DME: Communication with alternator

==
VTG Transfer Case (2)

53FC / not present
VTG: Supply control unit, terminal 30

55C4 / not present
No message from DSC

==
ABS-DSC DXC8 Dynamic Stability Control (1)

5F3A / not present
DSC: Transfer case malfunction
==

Should I start with the Voltage Regulator? I'm not sure why the problem only occurs when it's colder out. Could it just be a connector that's sensitive to the cold? Post #2 here says that a loose connector on a 745i alternator caused the 28D7 code.

https://www.bimmerfest.com/forums/sh...d.php?t=799370

Interesting that the Foxwell identifies the engine (management) as diesel. ;)

Your low voltage condition will produce a barrage of codes, most of which are purely related to the low voltage and can be ignored (and cleared once the low voltage condition is rectified - pun intended!).

I can't suggest a reason to the apparent alternator/rectifier/regulator failure in cold temps but it does seem to the cause of your problems. It's certainly where I would be concentrating any efforts.... checking all cable connections (including the connection on the firewall behind the jump terminal) and then the actual alternator output (with a multi-meter).

Yes, I found that odd too.

I'll check if I can find any loose connections and update if I find anything. Maybe the solution is to remain indoors when it's cold outside!

I think I forgot to mention that when I checked with the multi-meter before putting the key in this morning, I got 12.7 V. So the new battery seems to be okay.

Thanks for the advice.

Exactly - your battery is fine. That YouTube video was (is) plain wrong - although the intent was good - in suggesting that a battery under heavy load and reading 12.2v was on the way out.

My battery IS on the way out and reads 11.2v on full load via menu #9. Still cranks the car ok and still has about 12.5v on it with no load. My diesel has glow plugs that load the battery VERY heavily when the engine is cold, so I'll probably not see much over 12v under load even with a perfect battery. :dunno:

Ohms law... ;)

Good luck eking out a while longer on your battery. I bet they're more expensive in NZ!

A couple of more observations from yesterday:

- The engine was running at about 1k RPM when I started it and it was at 11.2 V. Perhaps running a little rough. I may have concentrated more on the warning lights in the past and ignored these two facts. The engine noise at idle isn't that noticeable from the driver's seat.

- When I used the accelerator to rev up to 2k - 3k, the voltage increased rapidly to around 13.7 V. When I released the accelerator, the voltage returned to about 12 V, before slowly climbing to a normal 14 V after a few minutes.

I haven't had time to re-seat the connectors yet.

Hmmm.. yeah, something is definitely funky with the charging system. The high idle and rough running could be related to the low voltage condition too - don't worry about any of the other issues until all you sort the voltage, as most (if not all ) of them will disappear.

My first thought is that you have lost a diode in the rectifier - and it's somehow affected by temp. The diodes are often "welded" to the connection points - perhaps the "weld" has failed and the connection is intermittent and temperature affects this... :dunno:

If you have the water-cooled alternator, the diode assembly will look something like this (I think): -

https://i.ebayimg.com/images/g/AI8AA...L9K/s-l400.jpg

The regulator looks something like this: -

https://images-na.ssl-images-amazon....BL._SX355_.jpg

Thanks for the ideas. I have the N62 which, from what I've seen, only has the Valeo regulator:

https://www.ecstuning.com/b-valeo-pa...318510090~val/

https://www.fcpeuro.com/products/bmw...eo-12318510090

I don't think the alternator is water-cooled.

From your pictures, unless they're not using the same scale, I'm guessing the rectifier is a different piece, correct? Is that in the alternator itself?

That looks easier - nothing is simple on the water-cooled alternators!

Yes, on the Bosch water-cooled unit, the rectifier (diode block) is built into the alternator end-cap. The regulator is then a separate bolt-on unit.

The Valeo units appear to use a single module for both functions, and the brushes.

A buddy is going to come over Monday to help me troubleshoot the connections. He's got a lot more automotive troubleshooting experience than me. It doesn't look like I need to drive the X5 until then.

I plan to update the Foxwell on the weekend, to see if it provides any more useful information.

If we don't find anything, I'm thinking the next step will be to change out the voltage regulator. Sound right to you?

Yep - sounds like the next step. Be nice to confirm it as the fault first though - perhaps try measuring the alternator output at the alternator itself, both cold and hot. You could also try some freeze-spray to goad the fault into showing itself, cooling down various parts while monitoring the voltage.

I just battled some electrical/charging system issues after a drained battery from a 7-day park at the airport. A couple things:

First, it sounds like your alternator is not charging correctly. Your miles are low, but E53's are getting very old and time takes it toll. With a brand new battery and no parasitic drain, you should be seeing between 13-14V a few seconds after startup, not minutes. I would guess a new alt is needed. Obviously, check wiring to the regulator first, make sure there is no chafing, melting, oil, etc. on it. Also, visually observe your drive belt making sure it is not slipping on the alternator pulley. Make sure it is not being contaminated with oil, and check tension. You should have a 170A alternator, which takes a lot of force to turn at peak demand and when you mention the "warm-up" issue, this could be the problem.

Parasitic drain: BMW TCU's go bad frequently. They will wake the car, which creates a ~1-2A draw for about 16 minutes. The car may be able to start, but the battery will be in a discharged state and with the demands of cold temps, (secondary air pump, heated mirrors, heated lambda sensors, etc.). You mentioned a battery tender, so you're probably ok, but I would disconnect the TCU if you are not using it.

Good point about the slipping the belt, iansanderson. That also fits the symptoms... I hadn't gone down that thought path as haigha hadn't mentioned any squealing noises or any other issues associatied with a slipping belt, but its certainly worth checking out too. :thumbup:

Great suggestions, guys. I appreciate them.

I'll have my friend check out the belts when we're checking the connections on Monday. I don't remember hearing any squealing.

In September, with the old battery, I parked it at the airport for six nights. No problems when I got back. It wasn't cold then.

Other than that, as noted, it's usually on the trickle charger in the garage.

This is the kind of freeze spray your mean, correct?

https://www.amazon.com/MG-Chemicals-.../dp/B0047Y9DKS

Have you seen anywhere in the Foxwell where you can see the voltage at the alternator? There isn't a lot of documentation for it that I've seen.

Yep - that the stuff - that's a serious one! :D

I don't think you can "read" the voltage at the alternator output via a data connection - that would require an AD converter on the alternator output that could communicate with the data bus etc. - not a current feature. A multi-meter is the best you can do - and ideal anyway.

The point of measuring the voltage at the alternator is to elimate any wiring issues. If it's ok at the alternator while the car diags read a low voltage, it's a wiring fault. If it's low at the alternator, the issue lies there.

Thanks for the clarifications.

I'm leery of putting the multi-meter on the alternator while the engine is running myself, but I'm confident that my friend will know how to do it.

I loaded the updates to my Foxwell today. No significant differences that I could see. The log said only change in the latest update was something for a Z3. I don't know if there were any updates between that one and the version I got when I purchased it a few months ago.

It was in the mid-50s when I started the engine and got the 4x4 light. DSC, ABS and TPF too after a few seconds, without changing out of Park.

After going into the gearbox data in the Foxwell, I saw 14.1 V at the battery but only 11.2 at the solenoids. That's the first time I remember seeing them being significantly different. This may be the warmest it has been outside where I've had the 4x4 and other lights come on.

I had popped the hood before starting the engine. I got out while it was idling and I didn't hear any obvious squealing sound from the belts.

One thing I noticed in the gearbox data was that all the "Level to L[n]" pins reported High except for L3. I don't know the significance of that.

After the oil temperature gauge was about half way up, I restarted the engine and all the warning lights went away.

My friend thinks it's the alternator. No belt slipping or squeaking.

Warmer today. 13 V from the new battery, just off the trickle charger. Dropped to 12.1 when I used the Foxwell in position 1.

Then, we got 11.8 V after turning the engine on. No error codes or warning lights this time, but it didn't rise above 11.8 V even after waiting until the oil temperature gauge was past half-way to operating temp. Same voltage at battery and gear box this time. Maybe 11.8 is barely enough to not error out the VTG, DSC, ABS and transmission modules, but still not right for proper performance.

Restarting the first time after warming it up this far didn't work either, still running at 11.8 - 11.9 V. Third time was the charm, immediately went to 14 V. That time, I used the dash Test 9, instead of the Foxwell. Probably not relevant, but noting it.

In good news, we also serviced my Stihl BR600 backpack blower. New filter, spark plug and cleaned the carburetor. Runs on the first pull again and idles better.

My friend's view is that it's better to replace the whole alternator because it's a relatively big job. Or is there an easy way to just replace the voltage regulator to rule that out?

I haven't seen any how to videos or write ups for the N62 X5 alternator or voltage regulator. I have the Bentley manual, but it doesn't go into detail that I've seen.

The engine runs great after it gets the proper 14 V and shifts are smooth after the transmission filter/gasket change and 3X fluid drain.


EDIT: Found this video which appears to be the N62

https://youtu.be/b8lobpyEldw (less than 14 minutes!)

A little hard to follow the commentary, but from what I can tell, he says you need:

- 10 mm socket for top brackets

- slot screwdriver to release clips

- T60 (release belt)

- 5/8" socket with breaker bar (16 mm?) to remove two bolts holding alternator to engine

- T50 (remove tensioner pulley)

- 13 mm socket to remove alternator after pulling it loose from engine

It appears he has removed the lower protection plate, but that doesn't seem necessary?

Yesterday it was a little warmer and I saw no problems on a trip across town. Around 14 V right away and steady round trip.

I found this thread which seems to be the problem I'm experiencing, though the OP's mornings were colder (around freezing):

https://www.bimmerfest.com/forums/sh...d.php?t=668157

The solution for him and a couple of others in the thread was replacing the whole alternator, though some suggested just replacing the VR may have solved the issue. Member upallnight is on that thread :)

One of the useful links is this video of replacing the brushes on the VR and cleaning up the slip rings on a Valeo:

https://youtu.be/aVvPzwtxdrM

I think I'm going to start with buying the VR and replacing. Removing the alternator seems straightforward based on the video I linked to in my previous post here. If the VR doesn't fix it, I'll replace the alternator. Opinions?

Questions:

1. Is there an easy way to disconnect the power to the alternator (remove a fuse, disconnect positive terminal under the hood, etc.), rather than disconnecting the terminals on the battery itself?

2. Realoem shows a different alternator for my 10/03 build than later models:

https://www.realoem.com/bmw/enUS/sho...diagId=12_1244

Do you think the Valeo regulator will fit both? (shows as fitting when I select my vehicle, but it's hard to tell if it fits both the -992 and -994 versions in the last two links below)

https://www.fcpeuro.com/products/bmw...eo-12318510090

The site shows two Valeo alternators that fit for me, but the first one shows up to 12/03, which covers my build:

https://www.fcpeuro.com/products/bmw...li-12317540992

https://www.fcpeuro.com/products/bmw...x5-12317540994

Use realoem.com and your ViN and it will show you part numbers specific to that particular ViN. Then go hog wild ordering from BMW and mention me as I'm apparently putting some German through a yacht financing course this month...[emoji857][emoji857]

Sent from my SM-A730F using Tapatalk

Thanks for the advice. The Voltage Regulator isn't listed or sold as a separate part on RealOEM, as far as I can tell. I did put in my partial VIN to get the page I posted previously.

I contacted this eBay seller with a great reputation. Their recommendation was to remove the alternator and check the part number on mine before ordering rather than relying on RealOEM or another site. I saw another poster who ended up with the wrong alternator by using the information there.

https://www.ebay.com/itm/100-NEW-ALT...A/271076047426 [probably the one I need by part#, doesn't list 2004 X5 ]

https://www.ebay.com/itm/NEW-ALTERNA...P/290786378197 [ only lists 4.8 for 2004 ]


Good luck with your parts adventure!

Definitely yes, get eyes on the alternator before you believe anything about what you have in there. Depending on how much time you have right now, you will probably be able to spend a few minutes removing the easy stuff above it, and can then get a camera down there to take a pic so you can read the brand or PN.

I have a Valeo 120A in my 06/2001 build 2001 3.0i. I bought a VR for a quick fix of the brushes problem, then bought the full rebuild kit from that guy in the youtube video, which I did about a year later.

You might find (and this would be the best scenario) that once you have the alternator out, you pop off the back cover and see that the brushes are worn down so one of them is barely in contact. Then you just replace the brushes or the whole VR and can be pretty sure you fixed the one and only problem. If you don't find that, it is less clear. And an intermittent problem like you have makes it harder to debug.

For my 2001 3.0i, Bosch and Valeo were used interchangeably. You can replace a Valeo that fits the 2001 3.0i with a Bosch that fits it. But the pulleys are different, so the unit as a whole is interchangeable, but no sub-parts are.

Thanks for the advice. I ordered the VR because it's the same one for both versions of the alternator in the 2004 N62. I also ordered the belt since it was only $13 at FCP Euro and qualified my order for free shipping, so only a $5 difference, in total.

My guess based on what I've read is at least one of the brushes isn't making good contact when it's colder or the sleeve is fouled enough that when it's cold the problem manifests. It could also be a diode probem as wpoll suggested.

The order probably won't be here until the first week of December, then I have to schedule the replacement with my friend. I'll update with the results when it's done.

Thanks for everyone's help so far!

a large voltage difference can be a ground or supply cable; the B+ cable has a disconnect at the jump point under the hood; several people have had a problem this year with that getting loose and causing voltages drops. The alternator feeds through that connection back to the battery.

when my alternator failed it was from oil getting into it and causing too much resistance on the fairly warn slip rings; i replaced the slip rings and brushes and it's basically good-as-new.

For somebody that just wants to nearly double the life span of their alternator; you could reverse the polarity of the armature slip rings and they will last nearly twice as long; only one of them wears (i can't remember which but with arc lamps it's the anode that gets beaten to a pulp so it's probably the - side (the electrons shoot across the gap from brush to slip ring) but i would have to measure to know for sure. I figured out a way to cut the supply bars and add some jumpers to reverse the polarity of the brushes ; i would love to do that on wife's alternator before the slip rings are too worn to help.

Thanks, Andrew. I'll check the cable. That's where I have my trickle charger hooked up. Its small cable sticks out at the edge of the windshield.

I'll disconnect the B+ cable when we replace the VR, to avoid an electrical mishap. I'm hoping I can clean any fouling of the slip rings rather than replacing them. With my low mileage garage queen, coming up on 41k miles, I don't expect they'll be too bad.

Interesting point about reversing the polarity. The video I linked to in post #33 showed the top slip ring fouled and the bottom one looking like new.

Since it's best practice to always remove the B- cable at the battery first, there's no need need to remove the B+. Just remove the B- at the battery and place it where it cannot contact the B- terminal on the battery, or wrap it in a rag etc. :thumbup:

Removing the B- involves removing the spare and the air suspension though, correct?

I trust my friend to remove the B+ under the hood, if that's safe for an expert to do (he has worked on cars for more than 50 years!). I just wasn't sure if the alternator wiring bypassed it, until Andrew confirmed it doesn't bypass it below.

Confusion abounds on the wiring of that B+ jump port in the engine bay - specifically whether it is the end of the line vs. a stop on the path from the battery to the engine bay. Even BMW-supplied wiring diagrams may not be right on this.

It seems to vary between 3.0 gas vs. diesel and 4.4+. From memory (consider it a guess), it is the end of the line for 3.0d and 4.4+ (all with water cooled alternators) and in-line for the 3.0i (with air cooled alternators). Search this forum for more info if you want, or just tell your friend to measure voltage after disconnecting it to be sure it's not live.

I have a 3.0i so my engine bay jump port is in-line, and disconnecting it there would isolate the engine. But I have a quick release installed on the battery's negative post, and with no air suspension or anything back there, I can loosen it without removing the spare tire. Took me a little effort to put that in there when I first got the car, but it's convenient and I think safer in that I'm not tempted to take short cuts when I know I really should disconnect the battery but might take a chance due to the hassle.

I can remove the B- terminal from the battery by simply lifting out the spare - this give me enough room access to get a 10mm ring spanner onto the B- terminal. Take about 3 minutes.... :thumbup:

Thanks for the information, guys. I'll let you know how the procedure goes :thumbup:

The first attempt resulted in making the problem worse :(

After replacing the voltage regulator, which took an afternoon, now when I start the engine the alternator doesn't appear to be working at all. The three times I started it, the battery light came on after scrolling to Test 8 on the dash, not even selecting it. The battery light hadn't come on before, just the other warning lights (4x4, DSC, TPFS). When I selected Test 9, voltage was around 11.2.

Questions on two things that could have gone wrong with the procedure:

1. The VR has a push down mechanism to release the brushes, after mounting it. I definitely heard a loud click after pushing it down. Is it possible to hear the click and not have pushed it down far enough to release them?

2. The B+ connector on the alternator was a pain to get off. We broke the retaining clip and couldn't find it. Is it just a plastic piece or does it have metal in it? I couldn’t find a replacement on RealOEM. We used silicone sealant to waterproof that side of the connector. It's also possible that since there was no clip, it came off as we struggled to get the alterator remounted.

Notes:

We replaced the belt even though the original had no visible wear.

I took a picture of the label on the alternator. It's still not clear to me which is the correct replacement part. The eBay listing I pointed to earlier says that TG17C027, as on my label, is the post 12/03 alternator. It also lists 2542918 (without the A at the end that's on my label). As stated earlier, I have a 10/03 build, original owner.

https://www.ebay.com/itm/NEW-ALTERNA...P/290786378197

We cleaned the slip rings. Both had a little bit of fouling. Still plently of copper.

Trans Prog Failsafe when cool outside. Battery? VR? Alternator?
 

Before putting an alternator back in always test at an auto parts store for free. New doesn't mean functional. You can. Test for continuity on the field winding through the slip rings but the car needs to send an initial spike of voltage to the field winding to jump start the alternator.

I'm about to refurbish wires Valeo alternator and will take to get it tested before I reinstall. I'm not replacing the VR as I'm pretty confident it's just worn bushes and slip rings having done the same process on my car about 15,000 miles sooner than wife's.

Some simple questions first:
Now that you see the label on your alternator, how well does it match with what realoem tells you? Mainly for curiosity. I found mine to be different.

A little confused by your reporting on the charging light (that looks like a battery) coming on. When you put the key in and turn it to on, with the engine stopped, that red light should be on. Is it?

When you start the engine and it runs and the alternator is generating sufficient voltage, that light goes out. In the olden days, that was a simple light bulb and a wire in a very simple circuit, so the light would go out when the voltage output at the alternator matched the voltage at the battery. In modern cars, the ECU is generally involved (in everything), taking full control and adding a bunch of other things to go wrong. I'm not sure which type your car has.

Clarification on your report would help.

A failed VR (not just brushes failed, but a circuit failure) can cause that charging light to not come on when the key is in and the engine is stopped.

Regarding the VR brush release mechanism clicking into place, I'd say that is a likely concern. I forget how the one on my X5 120A Valeo works - can you slide the whole shield thing up and off and then slide it back on?

On my 120A Valeo, that nut on the B+ terminal on the alternator is a plastic cover over a steel nut. 17 mm hex head, M8-1.25 threads. 13 Nm torque spec. So it's not just a cover. It's steel, needs to be tightly clamped to the stud, and the plastic cover is for insulation, since that is live voltage there.

First thing I'd do at this point is to get a M8-1.25 threaded steel nut and torque it on there. Some tape or something would be good to cover it as a temporary insulator.

If that does not do it, I'd take the alternator out again and try to inspect the clicking into place thing. I don't know how you could electrically test for a problem with that, so it's a mechanical / visual inspection. If that looks good, you can take it off and put it back on again - a little trickier than how you do it with a new one, but possible. Then there's always the parts store free bench testing.

When I refurbished my alternator, I never torqued the plastic insulated nut. The nut fell off and have me very similar errors as the VR not working.

So +1 on check the nut on the alternator and the B+ terminal.

Thanks for the recommendations.

The B+ terminal is a plug with a retaining clip. I included a picture below from one of the YouTube videos. I took the bottom protective plastic front plate off just now and found the broken part of the clip. It is plastic. The negative cable is held on by a 13mm nut. My friend torqued it down by feel.


Now that you see the label on your alternator, how well does it match with what realoem tells you?


All RealOEM has is the BMW part 12317540992 (supersedes
12317525440 (09/01/2003 — 08/09/2004)).

https://www.realoem.com/bmw/enUS/par...&q=12317540992

Neither part corresponds to anything on the alternator label. There wasn't any other label that I saw. I've asked the eBay seller about the compatibility and sent them a copy of the label. I'll update if I hear back from them.

A little confused by your reporting on the charging light (that looks like a battery) coming on. When you put the key in and turn it to on, with the engine stopped, that red light should be on. Is it?


I never noticed that red battery light coming on. Maybe it only comes on when it detects the alternator isn't working on the N62? It only came on the three times I started going through the tests and hit #8, on the way to #9. It has never been on, that I recall, in the pre-VR swap part of this saga. I'll test whether it comes on with the engine off when I get it off the jack stands.


Regarding the VR brush release mechanism clicking into place, I'd say that is a likely concern. I forget how the one on my X5 120A Valeo works - can you slide the whole shield thing up and off and then slide it back on?


It's a push down mechanism, but there's a cover over the VR (with the label in the picture in my previous post. I don't think I can remove the cover without taking out the alternator. With the undercarriage plastic shield off, I can see the alternator cover from the bottom but it's not going to be possible to remove the screws of the cover, from what I can tell. I can see the negative cable attached, but not the B+ connector.

I left the Battery Tender Jr trickle charger on overnight and it wasn't green when I checked it 14 hours later. It was 13 V measured at the B+ terminal at the firewall, so it appears to have charged somewhat.

I learned several valuable lessons and now the one about taking the alternator to be tested :)

Update to my responses below:

I just started the engine again and let it warm up.

I guess I don't pay attention because in the second position, which I rarely pause on, the battery light is on (as well as many others). I think because the alternator was kicking in immediately after cranking, I didn't notice.

The connection between the test #8 and the light coming on seems to have been a coincidence (3 times in a row). This time I started without going into the test menu and the light came on after about 10 seconds and remained on solidly. Voltage bounced around from 11.5 to 11.8.

I also did a scan with my Foxwell and got the following fault codes:

28D7
Not present
DME: Communication with Alternator


27DA
Present
DME: Alternator fault


The eBay seller confirmed that this is the correct alternator based on the photo of the label I sent (and included below):

ebay.com/itm/290786378197


EDIT: I was also able to spot the B+ connector on the alternator from above. I used the end of a wooden yardstick to try to press it down further. It seemed to be on solidly already, I didn't feel any movement in it.

Kinda removes all doubt - there is no connection to the alternator - has to be either the plug on the back or the brushes did not seat properly when the "clicked" down. :-(

If the plug isn't solidly connected could be the problem. If that connector is solid you have to take out the alternator and confirm the brushes seated then I would for sure bench test before reinstalling. The bench tester knows how to jump start the VR to self sustain.

To be clear the small control connector is the one of concern.

12v will not hurt you through your skin on your hand you don't need to use a wooden stick to test connections.

I would pull off and re plug the control plug in case it didn't seat. Very good chance that's the only problem.

The main reason the yard stick occurred to me was it was long enough to reach the plug, about 2.5 feet in, and has a flat edge that fits nicely on the groove on the back of the plug.

I don't think I have a tool that could pull off the plug from the top of the engine. My extended needle-noses are only about 18 inches. Plus I'd worry about doing further damage to the plug.

I'm guessing it's the brushes. I'm kicking myself for not stopping after extracting the alternator and replacing the VR. Then having it tested today, before reinstalling it.

I'm going to slowly tackle taking the alternator out on my own. As you guys have likely surmised, I'm new to a lot a of this.

I ordered some electrical contact cleaner that's arriving Monday.

My mechanic friend is great, but he's suffering from a dental issue that is causing pain. Hopefully, he'll get that resolved next week. He was generous coming over and helping me yesterday, but I don't want to lean to hard on him right now.

I appreciate all the help!

Trans Prog Failsafe when cool outside. Battery? VR? Alternator?
 

I missed the memo of which motor.

On the m54 I just removed the alternator yesterday and I had no problem unplugging the connector from the alternator.

I did remove the air box and the fan/shroud and then finally disconnected the aux cooling pump which was exactly in the way of removing the alternator

No worries, Andrew. I probably should have put N62 in the title.

A busy day today, so I didn't work on removing the alternator.

Some good news: I got the four piece GearWrench flex head set I mentioned on the Black Friday thread and Amazon sent me the 120-tooth version instead of the 84. That will come in handy for this job! I also got some low profile 3/8 impact sockets.

I didn't mention that when I took of the lower front shield, along with the broken retaining clip from the B+ plug, I found a lost clip from the air filter housing. At least five hundred miles since it dropped down! It's the back right one and is a pain to get off. After losing two, I tied the current one with an extension string-pull that came with one of my LED shop lights. I hooked the string to a post by the washer fluid reservoir. The clips were around $6 each on FCP Euro!

I disassembled to the point where I need to pull out the alternator yesterday. Easier the second time. The 120-tooth ratchets helped. I spent about half an hour trying to wrestle out the alternator without success. My friend, who is fifteen years older and has shorter arms, eventually managed to do it the previous time.

Any tips on getting it out?

It seems that the second (back) post that the long, bottom bolt goes through is hitting against the part of the alternator that sits behind it, and the bolt screws into. This prevents the alternator from sliding out.

In one video I watched, it said to move the alternator up and to the right (while facing the car), but there doesn't seem to be enough room to get it far enough to the right.

Edit: In this image the back part on the bottom right is where the long bolt screws into (rotate it about 90 degrees to get its installation position). My understanding is, immediately in front of that, there is a bracket on the engine that the bolt goes through.

https://www.realoem.com/bmw/photos/12317540992

An innovation I came up with, for lots of bright light, is hanging a four-foot shoplight from the hood. I split one of the chains it came with, 9 segments each side, and put the s-hooks on them:

Air cooled or water cooled Alternaror? On the M62s I've worked on they were water cooled and very easy to remove.

I always remove the fan and shroud makes it 10x easier to access the front.

When I took wife's alternator out last week I had to remove the bracket that holds the aux water pump and also disconnected the aux water pump to pull it though the space it occupied.

She has the 3.0 so it's quite different but think along the same lines.

Is the power steering hose in the way or the coolant reservoir? Unbolt and move aside etc. Lots of parts are on flexible hoses and can be moved out of the way.

It's air cooled. I've removed the fan and shroud. I removed belt and the lower pulley that's bolted on to the alternator (T50) (to the third bolt hole on the alternator, in the middle right in the picture in my previous post, near the green dot).

The power steering hose is in the way once it's slid forward, but the main challenge last time was getting it to that point.

On the 3.0, the alternator comes straight up. Have to move a few things out of the way. I didn't work on V8 with air cooled alternator so I can't think of specific help.

The TIS page isn't much help either.

https://www.newtis.info/tisv2/a/en/e...-parts/Fz5faNW

This step - "Remove alternator (2)".

Very useful... :rolleyes:

Reminds me of this

https://uploads.tapatalk-cdn.com/201...5760bf142f.jpg

LOL. Maybe you're supposed to remove the whole engine beforehand, as in the TIS diagrams. That would make it easier! :rofl: :rofl:

There's no way I can see to remove anything in the first TIS illustration before sliding out the alternator.

I think the back part that's stuck from moving forward must either get around the bracket on the engine by tilting up the front of the alternator and moving it to the right. Or, moving the whole alternator to the right and then turning it clockwise. I'll give it another shot today, if the weather gets better.

I got the alternator out yesterday... well, almost. I had to take the plastic cover off because I can't get the plug out. I removed all the silicone that we put on because of the broken clip, but still no luck.

The brushes are probably seated fine. I can't press the cap down further. My current theory is that the single little wire in the plug isn't connected, as suggested by Andrew. I know it's thin because I pulled off the protective rubber cap when trying to get the plug out ( also found a thread of what can happen if that wire is faulty, in that case at the other end, with some good pictures in post #8 https://www.bimmerfest.com/forums/sh...d.php?t=966587 ).

I'm trying to source a replacement plug. I've sent a question to this seller to check compatibility: https://www.ebay.com/itm/30339114461...m=303391144617

If any one knows a good source or the part number, please let me know.

If you have it out, test it they don't need the plug. Junk yard cut the plug off and butt splice

Good suggestions, Andrew, thanks.

I took a picture of the place the lower, long bolt goes, in case it's any help for any future reader working on getting the alternator out. I think this spot is the main pain point. There's not much room to get the part of the alternator that goes over the back and the bolt screws into over to the right to free it up. Also, the cylindrical piece, not sure what it is, behind it with the square metal protrusion on it, is closer than it appears on the picture.

https://i.imgur.com/oV6u1Xb.png

Today's novice question:

At what point can I test the alternator by cranking the engine?

A. When it's connected to the B+ and plug connectors and securely held in place and the B+ terminal won't touch anything metal, but not bolted in.

B. When it's bolted in, but without the belt.

C. When the belt is reinstalled.

D. When the large intake fan is reattached to the radiator and both its connectors are plugged-in.

I want to make sure everything is working before putting the silicone sealant this time. I'm taking the alternator to AutoZone tonight to have it tested.

Thanks!

Option C - with no rotation, you'll get no output. :thumbup:

Thanks, wpoll. I was afraid of that. Bolting it back in is the hardest part.

I may be able to reach the alternator plug from the left side now that I've take off the engine cover and the right side cover (facing the engine).

Did you have it tested at auto parts store? That's the most important test. Make sure it works before bolting in since that's the hardest part.

You can run the engine without the cooling fan. Not sure if your model has both fans like mine. I'm going to remove my mechanical fan for the winter.

That reminds me.

https://share.icloud.com/photos/081P...zA#Chicago,_IL

I've always wondered if I can stop the fan with my fingers I've always used a piece of foam or rolled up paper etc.

I took it to AutoZone. The clerk found the testing code, but when he put it into the DuraTest (?) machine, it said that test wasn't supported. He suggested I go to O'Reilly's down the street. When I talked to the clerk there, he said he couldn't do the test without the plastic shield with the connector on it. He was happy to sell me a remanufactured alternator, which he could get by tomorrow, for $280 + tax. Lifetime warranty. No thanks!

Thanks. Just the one big fan as far as I know.

Don't think I'll be trying that!

I'll point out a couple things:

1) I'm far crazier than average
2) I juggle fire, broken glass, radial saw blades
3) engine was cool so the clutch wasn't engaged
4) I tested with something else first.

It hurt less than a high/five. Seriously, but I've done similar before hundreds of times including petting plastic house fan still under power. It's very important to come in from the back side (that's what she said).

[emoji1787]
Why do I get the feeling that someone found their Christmas Bourbon?

No pressure, but do you have an empty Listerine bottle and my address?

Sent from my SM-A730F using Tapatalk

Got the connector off, finally!

Today's novice question: Is there a way to check continuity between the gold contact on the plug and the wrapped gray wire in the second picture, without stripping off some of the wire covering?

I looked to see if I could find the other end of the gray wire. Getting the cover off where it is on the top of the engine has proven unsuccessful so far. The plastic tabs are brittle and some are against a metal rail which makes them tough to release.

You can stab a pin through the wire's insulation to do a continuity test. Leaves a tiny pin-hole that won't need insulating.

Or... measure to pin #19 on the main DME connector - X60003. This is where that grey wire runs to. It also runs down to the oil quality sensor but the DME is easier to get at.

https://www.newtis.info/tisv2/a/en/e...4i-sav/sq82UoS

Thanks for the tips, wpoll.

I was able to get continuity from four of the eight pins on pins in the receptacle on the picture below (upper left & right, middle center, left bottom). All the red wires... does that make sense?

Oddly, the gray connector on the wire, which corresponds to lower right on the receptacle, doesn't have continuity.

This page, linked from the one you gave me shows that it's a two-pin (which the plug has, but there's only one wire and one pin on the receptacle end).

https://www.newtis.info/tisv2/a/en/e...4i-sav/Uvkk0p0

I'm pretty sure my alternator has two wires going to the two conductor plug.

I'm pretty sure there's only one for mine. There's only one gold connector on the plug in my post #76.

The post with pictures I linked to on bimmerfest, #8, only shows one wire as well. (645i N62).

https://www.bimmerfest.com/forums/sh...d.php?t=966587

In post #78, I wrote:

I was able to get continuity from four of the eight pins on pins in the receptacle on the picture below (upper left & right, middle center, left bottom). All the red wires... does that make sense?


Can someone please confirm that having continuity on these four red wires is correct for the gray wire? The plug pictured is on the right top of the engine, under the cover (I removed the top and right covers). It is where the gray wire from the alternator comes into the top of the engine via the front of a long plastic box.

Thanks!

Where are the four red wires? I can find no reference to that connector you pictured in post #78. :dunno:

I just watched a very interesting YouTube video that may pertain to your situation.

https://youtu.be/szc5zuK9Bo4

The video shows the signal from alt going to instrument panel not DME.

Watch the video it might have a connection to your problem.

Thanks for all the help guys! We got a brand new alternator from the eBay seller I linked to below installed this afternoon. Everything looks good so far :thumbup:

We'll have to wait until I take it for a jaunt tomorrow and then see how it behaves when I take a trip across town next week when the cold mornings come back.

On the connector, wpoll, it's under middle of the right panel (facing the front of the engine) that comes off after you remove the middle engine cover with four T25 bolts. The plug goes in sideways (near where you'd remove the valve cover I think). The gray wire from the alternator goes in the long plastic box from the front to the back of the engine.

Off to a dinner party but going to use my better half's vehicle tonight since it's over the mountain and I want to do a short trip in mine first.

I appreciate all the help!

A short update: I've taken four trips since replacing the alternator with a brand new one. Each time I checked the voltage and it has been around 13.8 V almost immediately.

Today it was a rare day below freezing and no warning lights or error codes. A little delay before seeing the voltage display because of the low temperature warning. The lack of warning lights staying on and lack of error codes is a good sign.

Thanks to everyone who helped me resolve this!

Hooray! You nailed it.. great result. :thumbup: