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

[haigha]

Originally Posted by wpoll

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) ...

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

[crystalworks]

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.

[haigha]

Originally Posted by crystalworks

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.

[wpoll]

Originally Posted by haigha

… 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?
…

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.

[haigha]

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.

[haigha]

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

[wpoll]

Originally Posted by haigha

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).

[haigha]

Originally Posted by wpoll

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

...

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.

[wpoll]

Originally Posted by haigha

… 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. ...

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.

Ohms law...

[haigha]

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.