P38 battery discharge

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my p38 drains battery after 4 days ingnition says key in when not so what is the right lube to use on ingnition switch and were to get it jellyspanners and any body
 
P Sykes said:
my p38 drains battery after 4 days ingnition says key in when not so what is the right lube to use on ingnition switch and were to get it jellyspanners and any body
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I made the mistake of using WD40 and that made it worse to be honest, Electrical contact cleaner to clean and a blow with an air line if you had one available it may be ok dry but some on here have said about a graphite lube, Im not that clear on the lube myself but mine is working dry at the mo....

I think its fluff from pockets that gets on your key that does the harm...?
 
thanks jellyspanners will try air line its not showing ingnition key in at moment and battery at 12.90 so no drain lack of use prob course intermit bat drain so will try blow line thanks
 
JellySpanners said:
There is so much on a p38 its hard to tell, it could be a relay stuck and not shutting a system down..?

if yours it an automatic there is a red led light by the gear selector, observe this when its dark as it shows if the becm has shut down by going out, you will need to sit in the car with all electrics off for a while...

Has your car got any accessories fitted to it...amp towing relays etc...?
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With an automatic switch to a Led lamp which exits a few seconds and then again softly illuminated. When car is closed this led lamp must be off?
 
I have the usual battery discharge problem on my P38 4.6 HSE and so am going to replace the RF receiver with the latest version. It looks a fairly simple unscrew/screw-up job, the question I have is does the key or anything else need to be recoded?
 
Robin Jones said:
I have the usual battery discharge problem on my P38 4.6 HSE and so am going to replace the RF receiver with the latest version. It looks a fairly simple unscrew/screw-up job, the question I have is does the key or anything else need to be recoded?
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No, the code is in the BECM, the RF receiver just what it says on the tin, it receives the code from the fob and sends it to the BECM.
 
True, my mate is coming to dig and brick a service pit in my barn so I can work standing up and wheel the transmission out on a transmission jack. The spare gearbox will come out of the breaker complete with the engine on the end of my excavator.
 
mikeateves said:
Hi,

Thanks for all the replies. The battery is less than a year old and I have had it tested and told it was fine so I suspect the car isn't going to sleep. Hadn't thought of the alarm not arming - will have to get this checked.

On another line I've just noticed this morning that the (gearbox) oil cooler has sprung a leak. Can anyone tell me how difficult this would be to replace?

Thanks,
Mike
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Hey Mike, just on the gearbox cooler issue. Easy to replace, just make sure you do both pipes with cooler as the threads will probably strip on removal!!! Only a couple of nuts to take off, bit fiddly getting the new pipes in... might as well do the gearbox filter while you have the oil drained too, very cheap and easy to do also.
 
I realise this thread is several months old but thought I'd share my experiences of a similar problem:-

My P38 4.6 HSE battery was going flat in 2 days due to the BeCM not going to sleep, drain current never dropped below 600mA.

The BeCM was being kept awake by the remote/alarm receiver constantly detecting a signal.
As I live in a rural area interference from other cars was unlikely.

I finally tracked the problem down to a device in my house. My Philips wireless TV extender transmits on exactly the same 433MHz frequency as the P38 key fob/remote/alarm system. I have several of these in the house which were never switched off. If I do switch them off the BeCM goes to sleep properly. :D

Note: lots of wireless consumer electronics use this 433MHz frequency including IR extenders for tv remotes so before condemning your BeCM make sure you have eliminated other sources of 433MHz.
 
eightinavee said:
To perform a becm sleep test on an LP RR,you need to connect a multimeter on a 10a range - between the battery neg lead and the neg post on the battery.If you are careful you can do this without losing the radio code/window settings etc.
After the interior lights go out,the current drain should drop down to less than 30ma after a few mins - sit and watch it,if the drain suddenly goes back up something is waking the Becm.If it stays at less than 30ma then all is well. If it refuses to sleep or constantly sleeps then reawakens,something is upsetting it.Try parking the car in a field in the middle of nowhere and redo the test.If it will sleep in a field then you have something working around where you park your car that is operating on or around 433mhz that is triggering the rf reciever.If you dont have a handy field,you can try disconnecting the rf reciever inside the rhr window.The new rf reciever - pn YWY500170 seems to sort out the issue,all the cars I have fitted them to I have not heard of since.
If the current drain is always above 30ma it is not always the Becm at fault,I have a 4.0se in at the moment which the cd changer always takes 150ma and the lpg ecu takes 120ma - even with a diesel spec battery it still needs driving every few days to avoid a non start.Once you go beyond wether the Becm is sleeping,it can get a bit tricky diagnosing where the power is going,the correct ETM and lots of time/patience are a must.Hope this helps:)
Click to expand...
Yes it does help. Our P38 has this battery problem recently. You say the rf of 433 MHz causes this. Well, we installed a Maplin Weather Station (Fine Offset WH1080) and this transmits at 433.9 MHz. What a blinking nuisance! Will have to move the P38 out into one of the fields. Thanks. Toby M.
 
@TobytheFarmer .... or, fit a jog unit (c. £7 to buy) and have the RF receiver "switched-off" so it ca't get the spurious signals and wake the BeCM up.
Then you just switch it back on when you want to turn the alarms off and open the car with your RR fob.
Search on here, for the answer. I fitted one this week. So far.... Bliss! An alarm enabled car and no more flat-battery.
 
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