E61 battery not charging
Discussion
My friend has just bought a 2006 E61 520D. Very cheap, as it has an electrical fault. If we can't fix it, the plan is to break it.
Previous owner says the car was working fine, then the battery wen't flat. Starts OK on jump leads, dies if disconnected.
He fitted a new battery, then a new alternator, then gave up and sold the car.
We have both batteries, and they charge up OK off the car on my C-Tek. We don't have the original alternator.
With a fully charged battery in the car, it will start and drive - no errors on the dash - but the voltage on the battery doesn't go up (stays at 12 - ish volts). Not charging at all. Battery holds charge in the car overnight. Voltage readings are the same when measured on the battery itself, and on the jump terminals under the bonnet.
We've checked that the alternator is connected OK (cables removed and refitted). The serpentine belt is installed correctly, and the crank pulley isn't slipping.
We've disconnected the IBS data plug, which apparently should make the car charge using a default program?
We've pulled the DDE (ECU) to check for signs of corrosion.
Code reader shows alternator and IBS errors, as well as several other faults from when the battery last went flat.
Any ideas what else it could be, apart from a faulty replacement alternator or the DDE?
Previous owner says the car was working fine, then the battery wen't flat. Starts OK on jump leads, dies if disconnected.
He fitted a new battery, then a new alternator, then gave up and sold the car.
We have both batteries, and they charge up OK off the car on my C-Tek. We don't have the original alternator.
With a fully charged battery in the car, it will start and drive - no errors on the dash - but the voltage on the battery doesn't go up (stays at 12 - ish volts). Not charging at all. Battery holds charge in the car overnight. Voltage readings are the same when measured on the battery itself, and on the jump terminals under the bonnet.
We've checked that the alternator is connected OK (cables removed and refitted). The serpentine belt is installed correctly, and the crank pulley isn't slipping.
We've disconnected the IBS data plug, which apparently should make the car charge using a default program?
We've pulled the DDE (ECU) to check for signs of corrosion.
Code reader shows alternator and IBS errors, as well as several other faults from when the battery last went flat.
Any ideas what else it could be, apart from a faulty replacement alternator or the DDE?
Is the engine earth strap connected properly, at both it's ends? Mine had corroded through at the engine block end and had come out of the terminal block connected to the stud.
Is the new battery coded to the car?
Has everything been connected back up properly?
Does the battery gain and hold charge in another car?
Is the new battery coded to the car?
Has everything been connected back up properly?
Does the battery gain and hold charge in another car?
He has swapped the battery with the one in his e39. Both batteries work OK in there.
He has disconnected and reconnected the alternator cables.
We have tried it with the IBS sensor and positive cables unplugged.
Car starts and runs fine from it's own battery, as long as it has been fully charged before trying. Holds a charge overnight and will start the car the next morning. No voltage increase at all with the engine running though.
We haven't physically checked the engine ground strap, as we assumed it wouldn't crank if it was bad. We will check it though, if we can find it.
Original and replacement batteries are both standard lead acid, so coding shouldn't be an issue in the short term
He's been in contact with the previous owner again. He actually tried 2 reconditioned alternators - one from ECP, one from eBay.
It's possible that the altetnators are incompatible with his car. We've found at least 5 different BMW part numbers being sold as suitable for E61 models by sellers, slthough RealOEM says that the one currently fitted is for an E64.
Since the alternator is controlled by the engine ECU, we are wondering if the "computer" part of his alternator just can't talk to the ECU properly, so never gets energised.
Oh, we also pulled the DDE ECU to check for water damage. No sign of corrosion.
He's trying to put together a 3 way deal on another 525d of the same age that has a fuelling issue. If it comes off, we'll rob the items he needs, and sell the rest of the car to someone who needs body panels and interior trim.
I can see how cars like this get scrapped because of relatively minor faults. Previous owner put £3k into the car and only got 2 months use out of it. Sold it to my mate for £850. Got to be worth £2.5k if we can fix it, £1500 if he ends up breaking it.
He has disconnected and reconnected the alternator cables.
We have tried it with the IBS sensor and positive cables unplugged.
Car starts and runs fine from it's own battery, as long as it has been fully charged before trying. Holds a charge overnight and will start the car the next morning. No voltage increase at all with the engine running though.
We haven't physically checked the engine ground strap, as we assumed it wouldn't crank if it was bad. We will check it though, if we can find it.
Original and replacement batteries are both standard lead acid, so coding shouldn't be an issue in the short term
He's been in contact with the previous owner again. He actually tried 2 reconditioned alternators - one from ECP, one from eBay.
It's possible that the altetnators are incompatible with his car. We've found at least 5 different BMW part numbers being sold as suitable for E61 models by sellers, slthough RealOEM says that the one currently fitted is for an E64.
Since the alternator is controlled by the engine ECU, we are wondering if the "computer" part of his alternator just can't talk to the ECU properly, so never gets energised.
Oh, we also pulled the DDE ECU to check for water damage. No sign of corrosion.
He's trying to put together a 3 way deal on another 525d of the same age that has a fuelling issue. If it comes off, we'll rob the items he needs, and sell the rest of the car to someone who needs body panels and interior trim.
I can see how cars like this get scrapped because of relatively minor faults. Previous owner put £3k into the car and only got 2 months use out of it. Sold it to my mate for £850. Got to be worth £2.5k if we can fix it, £1500 if he ends up breaking it.
The second 520 that he was going to do a deal for parts on turns out to be a 320. Strange that the potential seller didn't know what he had.
The car has now been checked with computer diagnostics (INPA?), all existing faults cleared, and driven for a few miles on battery power. No faults showing at all, but no life from the alternator. Very strange.
The chap who came round with the computer managed to get his tiny hands onto the back of the alternator and pull off the low voltage cable. Apparently the plug just had a single wire, and the plastic plug housing was in poor condition.
Need to find out if this connector is only supposed to have one wire, as there was space for 2 pins in the plug body.
The car has now been checked with computer diagnostics (INPA?), all existing faults cleared, and driven for a few miles on battery power. No faults showing at all, but no life from the alternator. Very strange.
The chap who came round with the computer managed to get his tiny hands onto the back of the alternator and pull off the low voltage cable. Apparently the plug just had a single wire, and the plastic plug housing was in poor condition.
Need to find out if this connector is only supposed to have one wire, as there was space for 2 pins in the plug body.
Sounds like you need to get another E61 beside it and do some compare and contrast - and possibly swap in the known good alternator for your one. If INPA is showing an alternator fault that may simply be as you say - the ECUs are not talking to each other properly. Is there a coding requirement for a new alternator when it is fitted?
I know what you mean re scrapping these things. My 2006 530i (E61) has cost £3k in work in the last year - starter, battery, rocker cover gasket, water pump etc. Luckily (touch wood) the electrical elements seem to be holding up so far - the mechanical bits, whilst expensive, are easy to diagnose and fix...
I know what you mean re scrapping these things. My 2006 530i (E61) has cost £3k in work in the last year - starter, battery, rocker cover gasket, water pump etc. Luckily (touch wood) the electrical elements seem to be holding up so far - the mechanical bits, whilst expensive, are easy to diagnose and fix...
Parts swap would be easiest. Shame the "520" we had lined up for that purpose turns out to be a 320.
INPA was showing an alternator fault at the start, but after clearing all the codes and driving the car, it showed no faults at all. This despite the battery voltage staying at 12.2 with the engine running. This is something that seems really odd, unless faults like this take longer than a few minutes to get logged?
Good to know that the plug should only have one wire, and that the fuel pump is on the same network. We are trying to find out the exact part number of the alternator that should be in the car, see if we can just get the correct regulator assembly for it. I assume the regulator pack includes the computer bit?
We will also have a closer look at the wiring back to the DDE, make sure it's in good condition. I wasn't there when the chap checked it earlier, it may just be a dodgy housing, or it may be the contacts or wire that he commented on.
Unfortunately we don't have access to a 'scope to look at the data stream.
My mate has been in contact with the seller again. Apparently he replaced the alternator when the fault first appeared, and it did seem to fix it for a few days, then it stopped charging again. Alternator replaced again, this time the fault didn't go away. Maybe the DDE interface to the alternator got "spiked"?
INPA was showing an alternator fault at the start, but after clearing all the codes and driving the car, it showed no faults at all. This despite the battery voltage staying at 12.2 with the engine running. This is something that seems really odd, unless faults like this take longer than a few minutes to get logged?
Good to know that the plug should only have one wire, and that the fuel pump is on the same network. We are trying to find out the exact part number of the alternator that should be in the car, see if we can just get the correct regulator assembly for it. I assume the regulator pack includes the computer bit?
We will also have a closer look at the wiring back to the DDE, make sure it's in good condition. I wasn't there when the chap checked it earlier, it may just be a dodgy housing, or it may be the contacts or wire that he commented on.
Unfortunately we don't have access to a 'scope to look at the data stream.
My mate has been in contact with the seller again. Apparently he replaced the alternator when the fault first appeared, and it did seem to fix it for a few days, then it stopped charging again. Alternator replaced again, this time the fault didn't go away. Maybe the DDE interface to the alternator got "spiked"?
Reading up on how the alternator and DDE interact, I get the impression that the alternator will continue to charge if communication with the DDE is lost.
Seems to suggest that the alternator will work in a default charge mode if the BSD cable is disconnected?
If this really is the case, that would help with fault finding.
Seems to suggest that the alternator will work in a default charge mode if the BSD cable is disconnected?
If this really is the case, that would help with fault finding.
Check also you have 12v + on the big cable coming from the alternator whilst not running (a small load would be better) taking your earth ground connection from the alt body then your checking both - and + connections at the same time 
wouldn't be the 1st time I have seen lack of continuity on this cable between alternator and battery + possibly broken cable or termination or blown main fuse 
the small plug like mentioned already does only have one comms wire to the DME , failing that get the alternator bench tested 
wouldn't be the 1st time I have seen lack of continuity on this cable between alternator and battery + possibly broken cable or termination or blown main fuse the small plug like mentioned already does only have one comms wire to the DME , failing that get the alternator bench tested 
Checked the alternator to starter cable by putting a stop lamp bulb onto the back of the alternator. Got the same voltage reading there as going directly onto the battery, so the main cables seem OK.
Sealed the broken coolant hose (tee stub to expansion tank snapped off) with a screw and PTFE tape, disconnected the BSD cable from the alternator, and started the engine. Voltage stayed steady at 11.8v. I'm reasonably sure that the alternator should put out some charge with the data cable disconnected, so it looks like the alternator is faulty. Mate reckons he has one with a noisy bearing that we can try. Will check that the mountings are all clean at the same time.
Strangely, at no point did we get any fault messages on the dash or iDrive display, and the battery light didn't come on at all.
After doing the above, we tried to remove the broken top hose. The clips came out OK, but the hose ends wouldn't pull off.
Sealed the broken coolant hose (tee stub to expansion tank snapped off) with a screw and PTFE tape, disconnected the BSD cable from the alternator, and started the engine. Voltage stayed steady at 11.8v. I'm reasonably sure that the alternator should put out some charge with the data cable disconnected, so it looks like the alternator is faulty. Mate reckons he has one with a noisy bearing that we can try. Will check that the mountings are all clean at the same time.
Strangely, at no point did we get any fault messages on the dash or iDrive display, and the battery light didn't come on at all.
After doing the above, we tried to remove the broken top hose. The clips came out OK, but the hose ends wouldn't pull off.
We fitted the spare noisy alternator today. Bit of a struggle, but got there in the end. Fitted a new top hose, connected everything up, and it's charging fine.
The alternator that came with the car is hopefully going back to be replaced under warranty. My mate will get it taxed and insured, then run it for a few weeks. If it's all good, he's got a bargain car for his mrs.
The alternator that came with the car is hopefully going back to be replaced under warranty. My mate will get it taxed and insured, then run it for a few weeks. If it's all good, he's got a bargain car for his mrs.
One slightly concerning issue:
The previous owner thought he'd fixed it having replaced the alternator twice, also a new battery. Not sure exactly in what order he replaced things.
He also jump started the car a lot during this process, using another car with the engine running, rather than just a jump pack or spare battery.
We know the battery is now good, as it's fitted with the one from my mate's E39. We also know that the alternator is good, as it was taken out of another 520d because the bearing is a bit rough (no charging issues at the time).
I believe that running an alternator with no load can kill it, but is there anything on the car that can cause an alternator to fail?
We are hoping that the owner was just a bit rubbish as a mechanic, and killed both replacements by bad practice when jumping it, or having a duff battery in the car and disconnecting the jump leads with the engine running.
I've never had an alternator fail in over 40 years and a million miles of driving. This car has had 3 die in a couple of thousand miles.
Also, despite everything appearing to work now, there was no sign of a battery light on the dash when the ignition was switched on. Does the E60 have a battery warning light that comes on with the ignition before the car is started? The car has the widescreen iDrive nav display, and did have "charging fault" on the display in one of the seller's pics. Does having the full iDrive system mean that the car doesn't have a battery warning indicator until there's a fault condition?
I used to have an E61 525D, but I can't remember.
The previous owner thought he'd fixed it having replaced the alternator twice, also a new battery. Not sure exactly in what order he replaced things.
He also jump started the car a lot during this process, using another car with the engine running, rather than just a jump pack or spare battery.
We know the battery is now good, as it's fitted with the one from my mate's E39. We also know that the alternator is good, as it was taken out of another 520d because the bearing is a bit rough (no charging issues at the time).
I believe that running an alternator with no load can kill it, but is there anything on the car that can cause an alternator to fail?
We are hoping that the owner was just a bit rubbish as a mechanic, and killed both replacements by bad practice when jumping it, or having a duff battery in the car and disconnecting the jump leads with the engine running.
I've never had an alternator fail in over 40 years and a million miles of driving. This car has had 3 die in a couple of thousand miles.
Also, despite everything appearing to work now, there was no sign of a battery light on the dash when the ignition was switched on. Does the E60 have a battery warning light that comes on with the ignition before the car is started? The car has the widescreen iDrive nav display, and did have "charging fault" on the display in one of the seller's pics. Does having the full iDrive system mean that the car doesn't have a battery warning indicator until there's a fault condition?
I used to have an E61 525D, but I can't remember.
Edited by clockworks on Friday 13th July 20:13
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