Electrical woes
 

2008 X5 4.8 died on my wife yesterday morning. It started, drove just fine with no warning lights and then suddenly 4x4 and other warning lights and as she was pulling into a parking spot it completely died.

At this point the battery was almost completely dead, can't remember but 11 point something volts and the car would reset when the start button was pushed. While removing the battery I noticed the negative terminal was corroded and slightly loose.

I charged the battery up with an AGM compatible charger and it was at 12.7V. Cleaned the terminal and reinstalled. Car drove just fine, no warning lights. Two trips yesterday afternoon roughly 15 miles total with no problems.

This morning the wife takes it and it dies again less then a mile from the house.

I'm going to charge the battery again and take it to Autozone and have it tested as it's only about one year old but really having a hard time wrapping my head around the fact that a battery has enough power to start a car and then die less then a mile later. These have warning lights if the alternator isn't working right?

Any ideas welcome!

William.

Intermittent / loose connection somewhere other than at the terminal?

Get the battery charged, tested and replaced if needed.

Also keep in mind these cars do not really have a Voltage regulator per say.

The battery needs to be registered and programmed as the DME controls the charging Voltage and a good battery and proper programming is key.

Not a problem if the same Amp Hour battery used.

Do you have an AGM battery in the vehicle?? Not sure I would use one of these in one of these vehicles.

Also have you checked the charging Voltage??

I think you can bring up the Hidden OBC menu and display the charging Voltage on the dash?? Search here or on the M5 forum for Hidden OBC Menu.

Proper charging Voltage should be around 13.5 Volts.

A poor mans load tester to to turn the headlights on with the vehicle off, leave the lights on for 2 minutes and the battery Voltage should not drop below 12.2 Volts on a half way decent battery.

And yes, when the battery or charging system goes haywire in these cars, your dash turns into a Christmas Tree!

Thanks for the input guys.

The original battery was AGM so that's what I replaced it with.

Good idea on the charging voltage. I've also got a power supply I'm going to set to 12.7V and hook it up in place of the battery and watch the current draw, obviously with engine off. Does anyone know what it should be? I'm mostly doing it to make sure it drops pretty low when the car is supposed to completely go to sleep, 15 minutes maybe?

Do not do this.

Leave well enough alone.

The modules typically shut down at about the 20 minute mark as I recall.

You have a bad battery, loose connection and/or a charging problem.

Since there is corrosion on the terminal, this tells me the battery is over charging and/or has a leak.

Just because the battery is only 1 year old does not mean it is still good. A 1 month old battery can be bad.

If the alternator isn't charging the car wouldn't there be a warning light?

The corroded loose terminal is the only reason I gave it another chance but those are all clean and tight now.

Alternator will not always give a warning, it should but not always.

Also sometimes the Alternator is working somewhat, slipping belt, bad diode, loose connection and this may not trigger a warning.

But also a bad/low battery causes all sorts of problems when the car is started the cranking Voltage drops too low and then the many modules in the car do not communicate properly.

I had a battery with a bad cell in my E46 and the dash lit up like a Christmas Tree. ABS, Traction Control, Brake light and some others.

I was surprised how much a bad battery impacted the car as a system.

Rule the battery out then go from there. You could have something draining the batter as well, this can EASILY be checked with a Voltmeter after an overnight rest.

I have a GMC that has a bad Onstar unit that will drain the battery if the truck sits for more than a few days. I pulled the fuse, but plan on just installing a relay to control the circuit.

So I charged up the battery and got the car back home. Checked with the car running the V across the battery is only 11.99 volts regardless of rpm so it seems like the alternator.

Something else strange though. I've got this battery:

Duralast Platinum/Battery H8-AGM at AutoZone.com - 6 reviews

And am using this charger:

Amazon.com: NOCO Genius G26000 12V/24V 26A Pro Series UltraSafe Smart Battery Charger: Automotive

The charger said 100% but I took the battery to Autozone and their tester said it was good but needed charging as it was only at 63%. They are charging it now and they'll test it again when it is supposedly done in an 1 1/2 hours. Now just deciding whether to wait or just start removing the alternator. They have a Valeo for $242.

A few things, do not toss in the towel on the alternator yet. 11.99 Volts at the battery means the battery is not fully charged and/or has a problem. Granted this is with the engine running and a semi healthy draw on the battery, but still 11.99 Volts is a dead battery at no load. Not sure what the no load Voltage was, but my guess not what a fully charged battery would be.

A fully charged battery should have a Voltage of 12.6 Volts at the terminal. If more than 12.6 Volts is measured, there is a surface charge on the battery that needs to be removed, usually 1-2 minutes with the headlights on, then wait 5 minutes and see where the battery Voltage stabilizes. If the battery continues to read more than 12.6 Volts, there is a problem, likely an internal short, somewhere in the battery causing the cell Voltage to read too high assuming the Voltmeter is reasonably accurate.

These cars are crazy the way they work and if the battery is low they may not charge properly, especially if the battery is sulfated or has a weak cell.

I am not a fan of the "smart" chargers as much as I am of the old school analog chargers. Matter of fact I am rewiring my first battery charger I purchased almost 40 years ago, long before I could drive, need replace the battery side cable as the insulation is old and cracked. What happens with the smart chargers they often drop back when the Voltage gets higher on the battery. If the battery has a problem it can cause the charger to no fully charge the battery. But if the battery has a problem, it needs to be changed anyway.

The battery testers the parts stores use are typically Resistive/Inductive testers. They do a good job for the most part, however, if the user does not enter the correct battery size, they can and will sometimes condemn a good battery or pass a bad battery.

I have a number of the Resistive/Inductive testers along with the good old 500 Amp carbon pile load tester. Often I use a combination of the 2 before I am 100% happy.

Interesting, thanks for taking the time to type all that. Straight off the charger it read 12.7 but I did not test it again after I took it out of the car. I was surprised at the 11.99 but it does somewhat coincide with their reading of 63%. I was going to pull the alternator and have them test that when I picked up the battery but I decided just to wait and see what happens with the battery first. I'm thinking there's a chance it simply won't charge up much more and they'll deem it bad and give me a replacement.

Of course none of this really explains why it died in the first place.

Smart move to wait and see. I just replaced the water pump on my 4.8L yesterday, not sure I would look forward to removing the alternator.

One thing I have noticed with many of the BMW's if you make a lot of short trips with it, best to charge the battery every 2-3 weeks.

My guess is either the battery is bad, or the vehicle is used for a lot of short trips with a lot of starts and stops.

You really should consider an OBDII smart phone App or a UltraGauge.

I have an UltraGauge that I move from car to car, but it is nice because you can set threshold alarms and keep and eye on Engine Temperature and Charging Voltage.

It is used for mostly 5-10 mile trips. I've had the alternator out when I changed the oil thermostat housing gasket. Not that difficult really but HEAVY.

I have INPA but a smart phone app would be simpler.

I have just heard about the dreaded oil thermostat housing gasket, might have to study up on this one.

INPA is not easy due to the need for a cable and laptop in the car.

The smart phone Apps allow Logging of the OBDII datastream and it allows you to keep the interface in the car and you will always have an OBDII with you while you are on the road.


Get an OBDII smart phone/tablet App and interface, typically $30 or less. These Apps are usually best for drivability issues and they support Emission Readiness Monitor Status, Freeze Frame and Live/Realtime data. They are also great for Logging data for review after the car has been driven and can really help find unusual problems.

Android - Touch Scan for $5.00 and ELM327 OBDII to Bluetooth interface.

iProduct - OBD Fusion for $9.99 and ELM327 OBDII to Wifi interface.

Some people prefer to have an extension cable to keep the interface away from their feet.

Something like these cables are often of interested:

http://www.amazon.com/gp/product/B00...A13I33IUTGJ9BK

http://www.amazon.com/OBDII-Extensio...Q9HPSGWZ2SB34Q

I usually suggest getting the OBDII interfaces from Amazon if you are located in the US/North America. Make sure you choose an interface that indicates that the order will be "Fulfilled by Amazon" otherwise you may be waiting for WEEKS for an interface to arrive from Asia. Ebay is another option, but pay attention where the interface will be shipped from, again weeks for an interface from Asia, so if you can wait and want to try to save some money, go for it, but if you need an interface soon, choose wisely.

Went back to Autozone to pick up my battery. Their charger said "charged" but tester said %74 need charging so they gave me a new battery.

New one measured 12.75V no load and with the car running the V across the battery was 14.1 V and steady regardless of rpm.

Everything seems fine now so crossing my fingers it was just the battery.

Sounds like it was good you listened and did not pull the alternator.

Until you get a "Known Good Battery" installed, it is hard to determine what is going on.

Keep an eye on the battery Voltage after about 3 weeks of driving to make sure the battery is getting a good charge and not running low due to short drives.

Get yourself an smart phone OBDII App, you will be happy you did.

I sprung for the BlueDriver setup. Will definitely be monitoring it for the next few days as the wife is pretty razzled about having it die on her... TWICE.

The oil thermostat housing gasket is for cars with an oil cooler. Look inside the lower driver side grill and if you have one of those it's pretty easy to change. If you don't have an oil cooler then you have an alternator bracket gasket and that thing is a nightmare to change.

Thanks again for your help!

Wish you would have asked before jumping on BlueDriver.

Over hyped and over marketed IMHO.

The $5-$10 Apps I recommend do a very good job.

The silly color graph they show on the website is for all intensive purposes totally useless. Almost ALL on tool/device graphing SUX. I export everything to .CSV and graph externally. Bluedriver supports this, but so do the $5 and $10 Apps I recommend.

I have been dealing with the Apps, OBDII tools and Pro Scan tools for a LONG time. I have 5 figures of tools and software so this is not my first rodeo.

I will be interested to see if Blue Driver properly supports Wideband O2 sensors or if they have made the same amateur mistakes most of the other App vendors have made.

I have had to straighten out a number of App problems for a number of different App vendors.

Anyway, will be interested to see your take and BD and what it can do.

Do not be surprised if you end up buying a $5-$10 App at the end of the day!

I have the oil cooler on my 4.8l X5 so hopefully I will not have a problem with the oil housing/alternator bracket leak I have read about.

I will need to look and see what is different on the models with the oil cooler.

The engine block is the same and has the mount on the side for the oil thermostat. On cars that do not have an oil cooler they made the alternator bracket larger to include a blanking plate to cover the holes. Both use the same gasket so are prone to the same leaking. The problem is that one of the bolts for the alternator bracket is underneath the engine mount so you have to take the weight off the mount and remove it to ultimately remove the alternator bracket and replace the gasket.

I received the BlueDriver yesterday. I just plugged it in and it worked so that's good, I haven't read the instructions yet but just browsing around the only V thing I could find was "module voltage". Not sure what that is and it can't be battery V as the car is running and it's only reading 12V... and then I start to get this sinking feeling... I get out my DIMM and sure enough, I'm back to 12 point something with the car running so it's not charging again and apparently I've apparently got an intermittent problem!

Current plan is to take the battery back out and charge it completely and while I'm doing that see if I can determine if I have excessive drain with the car off.

After it is charged I'm going to take it back to Autozone and have them test it as I really want to know if my charger is charging it completely.

Then re-install battery and go from there.

I had not researched this one to death, but I recall running across the problem and read about the alternator bracket. This is like the BMW I6 Oil Filter Housing Gaskets that leak all the time, same thing. But it sounds like the good news is with the oil cooler, I do not have the larger alternator bracket. I will check into this a bit more for future reference.

Yup. I have an E46 too, an 06 ZHP. Have done the VC, OFHG and CCV on that as well.

The problem/issue with any of the OBDII tools is they derive the Voltage from the OBDII port. This can be OK in some cases, but in others can be a bit misleading and you may have to come up with a "correction" factor.

I have not fully researched the E70 charging system, but it is very different then earlier models, this is why the battery registration is important. As I recall the alternator may not actually have a Voltage regulator and the DME controls the charging. There are some electrical interfaces back near the battery as I recall, I will see if I can find the info I have on the E70 charging system.

I just checked it again before I started tearing everything apart and it back to 14.24V car running, 12.7V car off!

I'd rather it just be dead than an intermittent problem!

I'm taking these measurements across the battery terminals with my Fluke meter. They are also exactly what the BlueDriver reported for "module voltage".

This may be of use - http://www.bmwmotorsports.org/pdf/e7...0and%20Bus.pdf

Not what I was looking for, but very close.

You also need to be aware that many of the newer vehicles do not always run the alternator as well. My 2005 GMC truck actually will turn the alternator off quite often and run just on the battery. This is the way the vehicle is designed and has often caused a lot of confusion for people trying to troubleshoot charging issues.

This is where the Logging features in tools like BlueDriver, Touch Scan and OBDFusion are very helpful. You can actually Log what is going on and see if there is a pattern and what is actually going on.

Yeah that's taken out of TIS. I have that and I'll look for info on the charging system. The thing you're talking about where the alternator cycles on/off BMW calls Brake Energy Regeneration where the alternator only kicks on during braking, coasting or deceleration. I'm like 99% certain my E70 doesn't have it but I'll double check. The newer models that have it actually have a light on the dash that tells when it's active.

I do not know if BMW shuts off the alternator, they may. My GMC truck does this for fuel economy and reduced load on the engine. There is actually a current loop on the accessory side of the battery cable that monitors current draw and will actually shut the alternator off.

At times you can see the Charging/Battery Voltage drop to like 12.4 Volts, which is NORMAL the way the system is set up on my GMC.

GM had to send out all sorts of Technical Service Bulletins because dealer technicians were replacing alternators left and right for no reason because they did not pay attention to the training info when these models came out.

I also know some performance cars also have full throttle alternator cut outs as well to reduce the load on the engine and try to get more power to the road.

You have to be careful on some of these newer cars and trucks before you write off and alternator and even then many shops have a hard time testing the alternators if they do not have internal Voltage regulators.

When I plugged it in to my charger the 100% light was flashing, the next lower light is 75% so all this tells me is it was between 76-99%. When my charger said it was 100% I took it to Autozone and their tester also said 100% so I'm now confident my charger does work properly and can charge it completely, making some progress.

While it was charging I've been doing some thinking and have a theory:

This is just a THEORY, PLEASE DON'T HESITATE TO SHOOT HOLES IN IT!

Couple things I'm certain of:

1. I know there was something wrong with the battery
2. Our cars have an Intelligent Battery Sensor on the battery (IBS)
3. The output of the alternator is controlled by some module and not a simple voltage regulator.
4. When installing a new battery you need to reset the charge adaptation in INPA.

When I read 12.x volts with the car running my old school brain tells me the alternator is not working, but what if instead of not working or deactivated as the new cars do, it's actually working just not trying to charge the battery.

It would work something like this:

When the system is charging the battery it knows the alternator output voltage and via the IBS it knows how much current is going through the battery to charge it. As the battery voltage rises the current will decrease and eventually plateau when that battery reaches it's maximum charge. As the battery ages the max output voltage decreases. Let's say for a specific battery it now at 12.5V. The car will remember that and when it gets back to 12.5V it will reduce the output of the alternator to 12.5V. At that point it will no longer be trying to charge the battery (better for battery) and it will be the minimum load needed on the alternator to operate the electrical system (better mpg).

There would also be an amount of hysteresis to prevent the alternator from constantly turning on/off. Lets say it's .1V, that would mean on my example above that the voltage would be allowed to drop down to 12.4V before the system would kick back in to charge mode and the alternator would put out 14.x volts until the battery was brought back to it's max of 12.5V where the system would kick back in to "cruise" mode and only output 12.5V.

This would explain why I'm getting reading that seem lower than expected and also why it's necessary to reset the stored battery info when installing a new battery.

And I haven't yet reset the battery in INPA. When I put the new battery in and read 14.x volts I assumed the problem was solved and haven't driven or had time to work on it again until now so that's the project for today along with adding the trailer hitch I installed a while back to the vehicle order.

My understanding is if you install pretty much the same AH battery you do not need to register/program for it. I would just for kicks check fuses. I think my 2008 4.8l charges all the time, but be careful and let the car run or drive it to make sure there is no charging going on. Some of the BMWs take up to 30-60 to start charging.

And through all of this there has never been an indication that there is a Charging/Battery/Alternator problem from the car?? Something is wrong here and I do not think it is actually the alternator, but I would have to study up on the power distribution system.

I also charge pretty consistently around 13.8 watching my UltraGauge.

Might humor me and try this, not sure it will resolve anything.

Disconnect the battery and short the battery cables together for at least 30 seconds.

Reconnect battery terminals, start vehicle and see what if anything is different.

You must be as old as I am. I do that whenever I change a battery. No idea if it does anything on newer cars but couldn't hurt.

Actually does more on the newer cars than the older cars.

Often times one or more of the cars modules can go stupid and often the capacitors all need to be discharged and put back in a "known" logic state.

Not sure if this is a problem with these cars, but sometimes certain programming/configuration can be lost or corrupt.

Before I would pull the alternator, I would be trying to re-register the battery first.

What is a bit strange/unusual is you do not mention that there is any sort of indicator that there is a charging/electrical problem.

So this morning battery read 12.54V started car and it dropped to 12.4V. I let the car idle with headlights on and it steadily dropped for a good 1/2 hour then at 11.95V it jumped to 14.x. I immediately shut off the car and battery read 12.7 and car fired right back up. Acting normal again now.

You need to monitor the Voltage to see what is going on.

There may be an intermittent problem still.

Use the OBDII App and Log the engine RPM, Speed and Voltage for a few days.

If it was me, I would confiscate the car from the wife for a few days to make sure things work properly, otherwise your X5 will be traded for a Silver Honda Odyssey!

I have been logging it since yesterday. Nothing strange till this morning. When it had gotten down to 11.95V I was certain the car wouldn't start, then when I shut the engine off I was surprised to see the voltage jump to 12.7 and even more surprised when it fired right back up.

The whole time it was idling in the garage I had both the BlueDreiver and my Fluke meter attached and they both read the same.

Why would you be so mean to someone you don't know?

All the women go to the same school and do the same thing. If the BMW strands her again, its/your days are numbered! :nanana:

Well that has been an interesting read so far.
I will add a point of reference. I got a 2012 e70 v8 back in the spring. The battery in it is the original OE. In May or so I checked the battery voltage a few times and it was always in the 11.9 range. Before a weekend camping trip I threw an older charger on it for a couple hrs, got it over 12v, and since then will connect my small trickle charger on it for a couple days here and there. I don't think the trickle charger puts out more than ~12.7 v but the battery got up to around 12.3v or so. The last few weeks its been off the charger completely. I need to check it again to see where it's at.

I drive 3 miles to work, 3 miles back, daily. So prime candidate for these issues.
But IN ALL THIS TIME I have never had an issue with starting, electronics, or any electrical indications of low voltage.
Despite that I did purchase a Jebsen voltage indicator that plugs into the cigarette outlet and I watch the voltage on that daily. Other than a few secs at startup I almost never see readings under 14v. I assume you have spotted the other thread on this but my post on it is here:
http://www.xoutpost.com/bmw-sav-foru...problem-3.html

Thanks for your input. It's seen more than three weeks now of daily usage on trips from 1 mile to 40 miles and no problems. It's definitely not constantly charging the battery, my old school brain finds this troubling but haven't found any concrete evidence that this is not the way it was designed so I just keep driving it and crossing my fingers lol.

Would really like to know for sure before the ski season starts.

6 miles of driving a day is not so good for these vehicles.

I usually put the charger on my cars overnight every few months just as a maintenance task.