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Hi All.

My father in law's 2002 MkII has a problem with a rapid battery drain.

He has had the ECU and BECM replaced, and has now been told it could be the "Body Module"??
When he leaves the car in eith P, N or 1, the little light next to the gear lever remains on, but in any other gear it stays off.
Also, more often than not, when he locks the car, all of the indicator lights stay on. If he unlocks it and locks it again, they may go off, they may not!!

The battery will drain to dead within a few hours of being parked and armed.

Any ideas on what may be the cause??

Thanks
Kieron
 

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THe P38/Mark II had no body module. In addition, wouldn't a 2002 be an L322/ Mark III on your side of the pond?

Which ever is the case he is being taken advantage of by morons that have no clue. Whomever is working on his rig is blindly tossing parts... very expensive parts at an issue instead of tracing the actual draw.

If it is a P38 it could be RF interference for a start. Well covered, search is your friend. From there, as with any draw you need to test the fuses to see which circuit actually is at fault.

If it is a L322/Mark III then he has no BeCM, but does have a body module. Again, the circuits need to be tested before tossing parts at it and supporting the mechanics family any further. Smaller things like the final stage resistor would be a more likely issue than the body module.
 

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1995-2002 Range Rover P38A
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RRTH- we do have 2002 P38's over here, crossover year.
Kieron- the BECM won't sleep unless the car's in Park. As RRTH says, battery drain is well documented on here. Use the red suggestions at foot of your post and search Battery drain in the box in top right corner
 

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1995-2002 Range Rover P38A
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I've known RF interference drain a battery but usually the indicators aren't affected.

If it is parked, why is it not in park?! You don't want it shifting and pulling on the park pawl or whatever.

I believe the red LED on the shift lever is usual on the auto.

I wonder is a door latch or microswitch is acting up making it think a door isn't properly closed so it doesn't go to sleep? If he peers in is the display lit up with any messages? Or an interior light still on afterwards?
 

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1995-2002 Range Rover P38A
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AFAIK the BECM should sleep if it's left in any gear - The BECM info document I have details a bit of the 'sleep' and 'activation' modes, and it says that the BECM will sleep after all the timers have timed out, and all of the activation inputs have been inactive for 2 minutes.

So in theory, no matter what state you leave the vehicle in - as long as it is left for 2 minutes, and none of the activation inputs have changed state, then it should sleep. That being said it also then says a few pages later that the activation inputs have to be inactive (which I am guessing is in the case of the light switches etc.)

Interestingly enough, the XYZ/gearshift switches aren't on the list of activation inputs, so shouldn't affect it sleeping.

If you are having the indicators left on all the time, then it does sound like an internal issue in the BECM, or possible a wiring fault, but if the BECM has already been swapped then I doubt it was the problem in the first place, as that's the bit that controls all the indicators etc.

Either way, whoever has been looking at it seems to be more interested in swapping parts on a hope of fixing it, rather than actually diagnosing the problem. It's a pity I'm away for work a lot over the next couple of months, otherwise I would have said to bring it down to me and I'd take a look!
 
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