30d 2002 BMW X5 parasitic battery drain solved!!!
Discussion
I Have to share my absolute joy, at last the thing that has spoiled a pretty good car has a last been solved.
I've been plagued by flat battery's for nearly three years, BMW had the car to look at when the problem first arose and straight away diagnosed a heater fan final resister as the culprit.
well this stopped the fan speed rising and falling at will but the battery would still go flat if not driven for 24 hours.
This meant carrying a power pack in the back just incase of the embarrassing failure.
The last weekend found the battery going flat overnight, so enough is enough back to BMW with it.
They have always said they could't find a problem, and this week for the first day of looking they could not find a drain' so they left it over night with an oscillascope attached and hey presto!! the thing came to life in the middle of the night, they recorded a 2 amp drain. Next day they left it asleep or so they thought in the corner of the workshop.
The mechanic wandered over to check if anything had been going on just at the right time, as he looked the thing flickered into life, so while it was active he started pulling the different module fuses out and when he pulled the telephone command module fuse it stopped drawing.At last problem sorted, as i don't use the phone in the car it won't be a problem not to have it anymore.Just glad to have found the problem, I hope this helps someone out there who is having the same problem.
A Very Happy Bizzy
I've been plagued by flat battery's for nearly three years, BMW had the car to look at when the problem first arose and straight away diagnosed a heater fan final resister as the culprit.
well this stopped the fan speed rising and falling at will but the battery would still go flat if not driven for 24 hours.
This meant carrying a power pack in the back just incase of the embarrassing failure.
The last weekend found the battery going flat overnight, so enough is enough back to BMW with it.
They have always said they could't find a problem, and this week for the first day of looking they could not find a drain' so they left it over night with an oscillascope attached and hey presto!! the thing came to life in the middle of the night, they recorded a 2 amp drain. Next day they left it asleep or so they thought in the corner of the workshop.
The mechanic wandered over to check if anything had been going on just at the right time, as he looked the thing flickered into life, so while it was active he started pulling the different module fuses out and when he pulled the telephone command module fuse it stopped drawing.At last problem sorted, as i don't use the phone in the car it won't be a problem not to have it anymore.Just glad to have found the problem, I hope this helps someone out there who is having the same problem.
A Very Happy Bizzy
Have you not just cured the symptom, not the cause though? The vehicle has been woken from sleep mode, allowing the telephone module to power up a draw current. Obviously, you've reduced the draw buy removing the phone. However, I seriously doubt the phone module is able to send a message to wake the vehicle from sleep mode (unless there is a safety critical reason why it would be able to - possible for tracking purposes?), so something else is likely to be waking it from sleep. All the time it is awake it's drawing more current than it should - it's quite possible the other modules (esp the body controller and major CAN gateways) will flatten the battery after a couple of weeks. I wouldn't want to be leaving it in an airport carpark while you go away for a couple of weeks as is.
Worth trying to find what the cause is - now if you had access to the BMW CAN spec you could monitor the bus and look for certain message ID's to figure which module was waking it out of sleep, but I guess only BMW could do that. There might be previous of this in BMWs records?
Sorry to be a bringer of doom on a rainy Friday night BTW
Worth trying to find what the cause is - now if you had access to the BMW CAN spec you could monitor the bus and look for certain message ID's to figure which module was waking it out of sleep, but I guess only BMW could do that. There might be previous of this in BMWs records?
Sorry to be a bringer of doom on a rainy Friday night BTW
muckymotor said:
A friend of mine is having a similar problem with his 05 Cherokee. The Jeep dealer can't find a fault and neither can an auto electrician, he now removes the battery negative lead every night...
tell him to get a "discarnect"......And OP, hate to busrt your bubble, but I am not sure you should belive them at BMW just yet.....
And there is clearly still an underlying issue....
Fingers croseed but let us know how you go on!
A good point VxDuncan, will pass your thoughts on to BMW, i'll let you know what they say, meanwhile i'm the happiest i've been with the car.
They had it on test for another 24 hours after they took out the fuse for the TCM, they recorded no more activity.Maybe they were waiting for something different to wake up.
It will be a while before i trust it 100%, there will always the dought in my mind that it won't start after a long weekend of no use.
Will keep you posted
Bizzy
They had it on test for another 24 hours after they took out the fuse for the TCM, they recorded no more activity.Maybe they were waiting for something different to wake up.
It will be a while before i trust it 100%, there will always the dought in my mind that it won't start after a long weekend of no use.
Will keep you posted
Bizzy
Edited by Bizzybirdy on Saturday 14th November 11:00
Have to say if I was not technical and not maintained this car personally I would have been broke long ago. Based on other posts I have replaced the final resistor the other day and the car was dead the next morning, another waste of money on part not necessary. Last battery was less than 3 years old and it was basically destroyed by the draw, new battery now only 3 months old and still dies over night. Just pulled the Telephone fuse and I guess will see if this is was the cause of the issue. Wanted to mention other problems related to this issue which nobody has been covering. After the car dies and you jump it or recharge the battery the car start first time with no issues. When you park and turn it off, it will not turn on even with the battery still fully charged. Only thing which works is to try to turn it on once or twice and then lock and walk away from the car for about 10-15 minutes and the car will then start, so much fun. About to install a second battery permanently for now till I figure this out, have been carrying two extra batteries fully charged for about 4 months now. If anybody has had issues related to any other part causing a draw on the battery would like hear. Have not got into going fuse by fuse to figure things out. Next if the telephone fuse does not take care of the issue.
Don
Don
Our X5 has a similar issue, sudden none starting when warm, leave for 30 mins and then starts no probs, I have replaced the fuel filter, fuel pressure regulator, fuel pressure sensor. It's a reet pain in the Jackson,now I am thinking it's a down to a budget battery that was fitted, any thoughts on this?
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