Battery drain on bmw 545i

[b21playa]

Hi all

After a few hours my car will drain the battery up to the point it will not start the car, and over night will completely kill it. I have changed the battery for a brand new 110ah and still the same. Had the alternator checked and was deemed to be charging the battery correctly.

Its been parked up for 2months now, and need this sorting, so looking for a mobile auto electrician to find the fault.

Anyone recommend one in the Birmingham area?

Thanks in advance

 

[plugsandsparks]

Not sure which model you have but a common fault is the "hedgehog" its basically the interior fan controller. If you google BMW Hedgehog you will get the idea, its almost a simple DIY job. Sorry I am 70mls north. lol

 

[b21playa]

Not sure which model you have but a common fault is the "hedgehog" its basically the interior fan controller. If you google BMW Hedgehog you will get the idea, its almost a simple DIY job. Sorry I am 70mls north. lol

Hi,

sorry should have mentioned it's an e61. I know the e39s were common for hedgehog.

what sort of rates should I be paying per hour?

 

[plugsandsparks]

Oh , there is a lot on google about that model. e.g High Battery Drain - Solved! - Bimmerfest - BMW Forums I cannot answer the hour rate question but I have found in practice that the cheapest solution is one where the diagnosis is done definitively rather than by trail and error of parts. I would look for a respected BMW specialist (not a dealer) in your area, cheers

 

[b21playa]

Oh , there is a lot on google about that model. e.g High Battery Drain - Solved! - Bimmerfest - BMW Forums I cannot answer the hour rate question but I have found in practice that the cheapest solution is one where the diagnosis is done definitively rather than by trail and error of parts. I would look for a respected BMW specialist (not a dealer) in your area, cheers

Cheers, I saw that but don't have comfort access.

 

[telectrix]

Oh , there is a lot on google about that model. e.g High Battery Drain - Solved! - Bimmerfest - BMW Forums I cannot answer the hour rate question but I have found in practice that the cheapest solution is one where the diagnosis is done definitively rather than by trail and error of parts. I would look for a respected BMW specialist (not a dealer) in your area, cheers

just scanned that link. should be retitled " 100 reasons not to buy a bmw".

 

[b21playa]

just scanned that link. should be retitled " 100 reasons not to buy a bmw".

I've had a fair few bmw's and on the whole have been great, its just this one.

 

[plugsandsparks]

TBH, its not really a problem with BMWs. If you have the software to interrogate all the ECUs that are in the car (and there are a lot) then its straight forward. Without a laptop and software you are peeing into the wind. If you are IT savvy , just get a copy of the BMW INPA software and a connector for the laptop to the diagnostic port and enjoy having a poke around. Has saved me shed loads, even managed to setup the turbo vanes as it gives real time boost and target boost .

 

[b21playa]

TBH, its not really a problem with BMWs. If you have the software to interrogate all the ECUs that are in the car (and there are a lot) then its straight forward. Without a laptop and software you are peeing into the wind. If you are IT savvy , just get a copy of the BMW INPA software and a connector for the laptop to the diagnostic port and enjoy having a poke around. Has saved me shed loads, even managed to setup the turbo vanes as it gives real time boost and target boost .

I have Bmw inpa and a launch x431 diagun, I will post the codes when I find them

 

[b21playa]

[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]DME 0027A0: Fan, electronics box - open circuit
LM 009CBC : Short circuit in a lamp unit - short circuit to positive
SINE 009D11 : DWA-data baus - short circuit to batt+
IHKA 00E714 : Message (battery voltage 0x3BE) faulty, receiver IHKA, transmitter[/FONT]

 

[plugsandsparks]

Have you measured the drain with an ammeter yet just to see how much current is actually being pulled. It can be a paff but the way I do it is to connect ammeter where I can see it through the rear window. Then lock the car up using remote, allow it to go to sleep and watch as the amps drop , taking notes of the readings at first connection, doors / windows closed, locked and alarmed etc. A cheap DC ammeter which measures up to 10 amps should be more than enough just don't put any real load on it while testing, like the windows or lights. Once you have those readings, you have the drain figures for real and sadly its now down to pulling fuses (although this can be quite difficult to get a cause and effect as you are constantly waking the car up ) it can take a good few hours to go through this and a well charged battery. With those error messages I would identify the fan and light fuses first to rule out the obvious

 

[b21playa]

Have you measured the drain with an ammeter yet just to see how much current is actually being pulled. It can be a paff but the way I do it is to connect ammeter where I can see it through the rear window. Then lock the car up using remote, allow it to go to sleep and watch as the amps drop , taking notes of the readings at first connection, doors / windows closed, locked and alarmed etc. A cheap DC ammeter which measures up to 10 amps should be more than enough just don't put any real load on it while testing, like the windows or lights. Once you have those readings, you have the drain figures for real and sadly its now down to pulling fuses (although this can be quite difficult to get a cause and effect as you are constantly waking the car up ) it can take a good few hours to go through this and a well charged battery. With those error messages I would identify the fan and light fuses first to rule out the obvious

I did try and measure drain once car had gone to sleep, and ammeter was registering only 0.01A IIRC.

What would cause an open circuit? I'll take the e-box fan out over the weekend and when its working along with its fuse.

 

[plugsandsparks]

The error messages can be a bit hard to interpret sometimes, basically the ECU is expecting a signal of some type and its not getting anything so it says open cct. It could be a wiring fault or whatever is supposed to send the signal could be broken. Can your software operate stuff like fans, etc and can it see inputs from switches and sensors ?

 

[b21playa]

The error messages can be a bit hard to interpret sometimes, basically the ECU is expecting a signal of some type and its not getting anything so it says open cct. It could be a wiring fault or whatever is supposed to send the signal could be broken. Can your software operate stuff like fans, etc and can it see inputs from switches and sensors ?

Tried to activate fan and nothing, maybe it needs a new fan