P38 BeCM help

Does anyone know any quick fixes for my Range Rover P38 BeCM, everything works but the central locking and air con, oh and the information you get for mpg etc on the message centre.

The central locking works on the key but the interior light does not come on, the man at Ranger 4x4 says check the switch, if thats faulty then its not triggering the BeCM. What does he mean by switch? Is it the outstations in the doors or the solinoid on the latch inside the door.

I had the condensor changed for the AC but still no joy, my man said there was not a live feed going to the compressor, we tested the unit bypassing it straight from the battery and it works fine. Is this down to the BCM? Is it worth sending the unit away to have the transistors replaced and repaired or does anyone think it might be something really simple im missing.

The interior light goes on when you open any other door but the driver door.

Thanks for any help.

regards Vince:doh:

WITH AIRCON SWITCHED ON AND ENGINE RUNNING SEE IF THE AIRCON PUMP SPINS THE MIDDLE BIT OF THE PUMP PULLEY, IF NOT HIT IT WITH A BLOCK OF WOOD

oops sorry bout caps.

i doubt the issues are the becm that your having.

if hitting it doesnt work, have a look on rangerovers.net theres a fix but its a long winded explanation.

interior light, sounds like your door lock mech needs stripping out, work the internals with a bit of vaseline clean the connections and try it without putting it back in the door, this should sort it!

mpg/msg centre, is it just the mpg or all the display, you need to take it out and see what the score is. to do this you should take battery off but if you do that then you will need eka code. make sure door lock is fully functional before you take battery off!!

if you dont take bat off you could end up with airbag fault or blowing air bag!

interior light sounds like the switch in the door is jammed in the open position

The mesage centre works fine with everything else except from the stalk I press the buttons and nothing, I must say ive not tested the steering stalk for fault. The aircon works fine with a live feed from the battery but when connected to the loom there is no power.

As with the door switch further investigation will be needed on my next day off thanks guys.

vinnylondon said:

The mesage centre works fine with everything else except from the stalk I press the buttons and nothing, I must say ive not tested the steering stalk for fault. The aircon works fine with a live feed from the battery but when connected to the loom there is no power.

As with the door switch further investigation will be needed on my next day off thanks guys.

Click to expand...

With the aircon can you see a book symbol in the bottom right of the HECAC unit (the bit that shows what temp you and your passenger are selecting) if there is one you need a diagnostic to reset a fault code which will enable the aircon to work. Other points are:
a) Did the chap who replaced the big condensor (big alloy rad in front of the main radiator) also re-gas the system?
b) Don't forget its winter weather and you need a difference in temp. Select LO LO on the HEVAC give it some fan speed MAX. select FACE distribution control, open FACE vents, open the doors, selct RECIRC, engine running to 1500 and look at the aircon compressor in the engine bay one pipe comming off it should be warm the other freezing.
c) Your chap said no direct feed, there will only be one and it will be switching if the system is running as it should.
d) Look at you compressor again without engine running the gap between the compressor and its clutch should be just under a millimeter. This is critical on early cars as there was known fault with the wiring that didn't give max volts to hold it in, slipage caused wear and if the gap is too big the compressor stops working - LR did a kit with an additional relay and loom to the alternator - fitted on later cars.
e) The diagnostic check and reset may show other reasons for failure. ie: loose drive belt, solar sensor, int and external temp sensors - the interior has a high failure rate, expansion valve sticking, low refrigerant charge (you may have a leak regardless of having it just done - you can get a leak sealant nowadays that goes in with the gas and can get older systems going again by reviving the seals and you can get one that does both seals and metal leaks.

Wow what a great reply. You have givem me plenty to look at and play with.
When we put a direct feed from the battery the compressor works fine and you get one pipe hot and the other cold as you said. He done a test on the wiring and there is no power so thinking a fuse or broken wire.

thanks again you have been really helpful.

Regards Vince

vinnylondon said:

Wow what a great reply. You have givem me plenty to look at and play with.
When we put a direct feed from the battery the compressor works fine and you get one pipe hot and the other cold as you said. He done a test on the wiring and there is no power so thinking a fuse or broken wire.

thanks again you have been really helpful.

Regards Vince

Click to expand...

I suppose that you have the Aircon turned on? The switch on the HEVAC unit turns the aircon on when the light is OFF. If the light on the switch is ON, the aircon is OFF

very confusing!!! you should hear/see the compressor kick in with a click when the light is off!!!

dunno what fuse the aircon is on, i remember seeing an ice crystal symbol in the fuse box, but with LR logic its prolly the fuse for the clock!

just thought, will the aircon stop if the fan's fuses are blown or the relays?