Battery drain on my P38 Range Rover 4.6 HSE auto

Please can you help me, I have been suffering from a dead battery on my Range Rover 4.6 HSE 1998 Auto, if it not used for 2-3 days.
I have checked the following items:

• Replace the battery and it still only lasts 2-3 days
• Checked alternator out put with multimetre, and all is well (13.8 volts on tick over)
• Checked the BeCM, and it is only pulling less than 0.05A, and does not seem to be wakening for any unknown reason
• Disconnected the RF receiver to discount any interference at night.
• Checked ear thing

Only one thing I can not explain is that there is a faint red light on the gear selector when in the parked position, which stays on when the car is locked up.
This Range rover has had a LPG conversion on it.


Any help please Dolly……..

There is already another thread on this subject, check replies from there.

There are many sources of battery drain you are expriencing on the P38.

Check www.rangerovers.net which cover many of them, and also suggest fixes.

Matt.

Thank for that, i have now found out that my volt meter was faulty,and the real current draw is 0.6 Amps.Have pulled all the fuses,but still it is drawing 0.6 Amps,with the alarm on or off.

Regards
Dolly

sounds like youve covered most causes. when parked do you leave the rangy in the park position otherwise this can cause battery drain. just a thought.

Yes i do leave it in the park position, i will try it in a different position.

Thank you for your input.

Dolly

BECM fault

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Still trouble with battery drain on RR 4.6 HSE have narrowed this down to the Becm not "going to sleep mode" after the normal 2 minutes.
Drain is 0.6amps and should be 0.06 Amps when in sleep mode.
Any sugesstions about repair, I believe it could be a blown Diode.
Could a competent Electrial engineer fix, and does anyone know of a repairer in the UK.
Any suggestions

some usefull info here.............
www.rangerovers.net/repairdetails/electrical/batdrain.html

• Disconnected the RF receiver to discount any interference at night.

Hi,
Could you please tell me where to find this RF receiver?
Do you have any pictures?
I would like to try the same thing on my Range.

Thank you.

Have you disconnected the rf receiver since you have sorted your multimeter ? The current drain when the becm is asleep should be less than 30ma,usually 20-25ma.You can also determine if it is an underbonnet fault that is keeping it awake by removing the three large 60a maxifuses from the engine compartment fusebox.Beyond that the next stage to push it on further is to stick it on testbook and do a sleep test,it wont make it go to sleep but it will monitor all the relavent switch states to make sure everything is in place to let it sleep.

Check my thread about bad alternator... i had strange drain issues. This could be different issue, due to my BECM goes sleep and current drain goes less than 0.05A.

http://rangerovers.net/forum/viewtopic.php?t=5827

dolly said:

BECM fault

--------------------------------------------------------------------------------

Still trouble with battery drain on RR 4.6 HSE have narrowed this down to the Becm not "going to sleep mode" after the normal 2 minutes.
Drain is 0.6amps and should be 0.06 Amps when in sleep mode.
Any sugesstions about repair, I believe it could be a blown Diode.
Could a competent Electrial engineer fix, and does anyone know of a repairer in the UK.
Any suggestions

Click to expand...

Hi - very interested in this as well. Same drainage on my P38 (2001) because the Becm not going to sleep. The auto-electrician I took it to said I need a new Becm , I'm abit sceptical though. I tried to look into this myself by measuring the drainage but the alarm just keeps bl00dy going off everytime I disconnect the battery and am just frightened of it going into "key lockout" mode. Is it worth paying Land Rover lots of dosh to diagnose it, as they may find the actual problem, not necassarily the Becm. I've already tried disconnecting the RF receiver, doesn't make any difference.

Cheers.

This is a common problem.

The best fix is to replace the RF Reciever under the parcel shelf on the drivers side. This picks up outside signals from transmitters, even as simple as wireless doorbells can wake up the onboard computer draining the battery.
Land Rover updated the part in 2004 so unless you have allready upgraded this, no P38 has it.

It is simple to replace and saves messing with solutions of using switches under the bonnet or disconnecting the RF Reciever over night. The part costs around £100 but it worked a dream on my 2000 model and it is the correct part.

James.

seasider said:

Hi - very interested in this as well. Same drainage on my P38 (2001) because the Becm not going to sleep. The auto-electrician I took it to said I need a new Becm , I'm abit sceptical though. I tried to look into this myself by measuring the drainage but the alarm just keeps bl00dy going off everytime I disconnect the battery and am just frightened of it going into "key lockout" mode. Is it worth paying Land Rover lots of dosh to diagnose it, as they may find the actual problem, not necassarily the Becm. I've already tried disconnecting the RF receiver, doesn't make any difference.

Cheers.

Click to expand...

If disconnecting the reciever didnt work then the new part number wont help you,what you need to do is to get someone to work their way through all the cars circuits - disconnecting each one in turn to work out what is taking the current.It may even be that the Becm is sleeping,it is something else drawing current.The last one I did turned out to be the CD changer and the Radio memory taking far more than they should,and the Lpg Ecu was taking 120mA all the time as well.
What you need is an accurate diagnosis.