P38 battery drain

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
P

P38rangerover

New Member
Posts
5
Location
Yorkshire
Just bought a 2002 p38 4.0. When parked up overnight the gear selector stays lit up like a Christmas tree and the battery goes flat. I have unplugged the aerial on the rf receiver and this did not solve it.
 
P38rangerover said:
Thanks. I have tried that now. The barrel pops out fine. The gear selector is still lit up overnight. Any other ideas?
Click to expand...
Welcome to LandyZone.
If you've just bought the car then may be worth checking the battery voltage, earth straps and if there's any damp in the cabin or engine bay electrics. These are all the usual suspects on our beautiful motors. Let us know how you get on.
Tricky.
 
Have a good read of the attached BECM SID. Page 10 lists all the inputs that affect sleep mode.
 

Attachments

  • BECM SID CONSOL.pdf
    2.2 MB · Views: 240
pwood999 said:
Have a good read of the attached BECM SID. Page 10 lists all the inputs that affect sleep mode.
Click to expand...
I know it wasn’t my thread but this is brilliant information. It reads almost exactly how I understood the system with all the details. Many thanks.
Tricky. :)
 
One more point on the RF Receiver. If there's a mobile mast nearby, even disconnecting the antenna doesn't always work. (my local Wickes car park always caused issues until I fitted Marty's filter box) Easiest check is to drive to a location with crappy phone coverage, and then try the sleep test again. Alternative is to disconnect the receiver completely. Then lock the car with the key, and wait for sleep with zero RF to interfere.

Otherwise go through all the inputs in the SID and find the culprit. You can fake the door closing when door is actually open by putting the latch into the closed position with a screwdriver. Bonnet switch can simply be disconnected. Other stuff is harder, but with door & bonnet bypassed and open, you can easily measure the battery drain current with a cheap DC Clamp meter. Much easier then spotting the gear light tell-tale in daylight !! Same clamp can also be used to check other circuits for undesirable current stopping sleep.
 
pwood999 said:
One more point on the RF Receiver. If there's a mobile mast nearby, even disconnecting the antenna doesn't always work. (my local Wickes car park always caused issues until I fitted Marty's filter box) Easiest check is to drive to a location with crappy phone coverage, and then try the sleep test again. Alternative is to disconnect the receiver completely. Then lock the car with the key, and wait for sleep with zero RF to interfere.

Otherwise go through all the inputs in the SID and find the culprit. You can fake the door closing when door is actually open by putting the latch into the closed position with a screwdriver. Bonnet switch can simply be disconnected. Other stuff is harder, but with door & bonnet bypassed and open, you can easily measure the battery drain current with a cheap DC Clamp meter. Much easier then spotting the gear light tell-tale in daylight !! Same clamp can also be used to check other circuits for undesirable current stopping sleep.
Click to expand...

Didn't help with my wireless weather station sensor either.
 
You must log in or register to reply here.

Similar threads

B
P38 auto gearbox problem.
Replies
9
Views
440
Datatek
Datatek
P
L322 Battery Drain
3 4 5
Replies
82
Views
2K
ABRon
A
Cyrus 200
Battery Drain
Replies
6
Views
473
Cyrus 200
Cyrus 200
O
p38 2.5 diesel
Replies
6
Views
789
omlette
O
Paul Coddington
P38 throwing a tantrum?
2
Replies
20
Views
609
Datatek
Datatek
Back
Top