Gearbox fault and electrical issues, P38A Diesel.

Also, forgot to mention that over night it immobilised itself, for no reason. My wife went out to it this morning and it was immobilised. Unfortunately I was at work and couldn't help her. When I got home earlier and before I changed the fuse box I used the EKA code and unlocked it and it was fine, apart from all the above issues that is the main problem.

Bad earths, corrosion in side the sleeve of the battery cables, corroded connectors at the BECM due to damp carpet for starters.

Well, I've already checked and cleaned the engine earths and tried putting a jump lead from the engine to the body, no joy. Also I did the following checks for continuity and voltage drops at the start ;
Alternator direct at idle - 13.98v,
Negative cable loss check under load - 0.27v,
Positive cable loss check under load - 0.19v,
Voltage drop between negative terminal at battery and first body earth point - 0.01v,
Voltage drop between first body earth point and engine block - 0.17v,
Voltage drop between bolck and alternator housing - 0.06v.
So, any of those help point us in the right direction?
I intend to open the BECM in the morning to see if there is any damp inside it.

B16FUN said:

Well, I've already checked and cleaned the engine earths and tried putting a jump lead from the engine to the body, no joy. Also I did the following checks for continuity and voltage drops at the start ;
Alternator direct at idle - 13.98v,
Negative cable loss check under load - 0.27v,
Positive cable loss check under load - 0.19v,
Voltage drop between negative terminal at battery and first body earth point - 0.01v,
Voltage drop between first body earth point and engine block - 0.17v,
Voltage drop between bolck and alternator housing - 0.06v.
So, any of those help point us in the right direction?
I intend to open the BECM in the morning to see if there is any damp inside it.

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Alternator voltage is low, should be 14.2 volts, could be an intermittent alternator fault.

I'll run another check on it in the morning and if it's low I'll look to replace it but in the mean time tomorrow I'll still split the BECM down to check for damp. Cheers for your advice Data!
Andy.

FIGURED IT OUT! There is a break in the power feed to those fuses. If I put a power feed into the three fuses everything powers up fine and the faults go away! Speaking to an auto electrician and he advised the loom that runs to the BECM under the drivers carpet corrodes and you get breaks in the wires about 6" forward from the seat base. So, I can now attack it with avengance in the morning!!! SO HAPPY!:amen::bounce:

NICE NICE NICE

Nice one mate

Cheers mate. Just been working through the electrical troubleshooting section of the RAVE CD and I'm looking to trace the brown and the brown/light green wires to look for any breaks.

B16FUN said:

FIGURED IT OUT! There is a break in the power feed to those fuses. If I put a power feed into the three fuses everything powers up fine and the faults go away! Speaking to an auto electrician and he advised the loom that runs to the BECM under the drivers carpet corrodes and you get breaks in the wires about 6" forward from the seat base. So, I can now attack it with avengance in the morning!!! SO HAPPY!:amen::bounce:

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Take the plastic finisher off and you will find the loom under it. It has no protection the wires are a loose bundle with the odd bit of tape. On mine the channel they sit in was full of water from the "O" rings and an assortment of screws and other bits that must have been there since the car was made. There was some damage to the insulation but it had not caused a problem. Cleaned it all up and dried out then added some protective tape on the damaged bits.

Well, checked the loom out, nothng wrong with it, no damp and no corrosion of the wires and no issues getting the power to the BECM. So, I took the BECM out and opened it up, no damp and nothing I could see as an issue. Took the top PCB out and couldn't see any burnt or damaged tracks. So, I thought about putting some ignition fed live feeds into the circuits as they worked when I put a direct feed into them. I decided to put it back in the car while I figured out where to take the feeds from but when I turned the ignition on, it's all working again. I at least now know the fault lies within the BECM but I can't see an issue. The only main bit's that I disturbed when opening the BECM was the ribbon cables so I could lift the top PCB up and I know that the fuse 6,7 and 17 circuits (or at least one of them) runs through one of these so I'm hoping that the iffy connection was in these and by reattaching them it has sorted it. If not and it happens again then I have two choices, see if somene can offer a repair on the existing BECM although I would need a quick turn around as the car is my wife's daily driver or I can get a replacement BECM, Engine ECU and Key from my local breakers for £150. We'll see how it goes but who does BECM repairs?
Cheers,
Andy.

B16FUN said:

Well, checked the loom out, nothng wrong with it, no damp and no corrosion of the wires and no issues getting the power to the BECM. So, I took the BECM out and opened it up, no damp and nothing I could see as an issue. Took the top PCB out and couldn't see any burnt or damaged tracks. So, I thought about putting some ignition fed live feeds into the circuits as they worked when I put a direct feed into them. I decided to put it back in the car while I figured out where to take the feeds from but when I turned the ignition on, it's all working again. I at least now know the fault lies within the BECM but I can't see an issue. The only main bit's that I disturbed when opening the BECM was the ribbon cables so I could lift the top PCB up and I know that the fuse 6,7 and 17 circuits (or at least one of them) runs through one of these so I'm hoping that the iffy connection was in these and by reattaching them it has sorted it. If not and it happens again then I have two choices, see if somene can offer a repair on the existing BECM although I would need a quick turn around as the car is my wife's daily driver or I can get a replacement BECM, Engine ECU and Key from my local breakers for £150. We'll see how it goes but who does BECM repairs?
Cheers,
Andy.

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Rick the Pick

Check the white connectors behind the kick panel on the door side of the drivers foot well.
Fractured wires can be a devil to find as they make and break inside the insulation where you can't see them.
defective solder joints in the BECM is another possibility, you need a good magnifier to see them and know what you are looking for.

Cheers guys. Well, having been oput in it it has thrown the faults back again. I'm pretty sure that it is the BECM that has the problems as apposed to broken wires in the loom as when I run external feeds into the three fuses (6,7 and 17) it clears the faults and I take the feed from the posts that the wires from the under bonnet fusebox run to. If I replaced the BECM, Engine ECU, and key my question is would I also need a gearbox ECU or will my existing one talk to a replacement BECM? I'll pm Rick as well to ask about getting my existing one repaired (my preffered option I think).
Cheers again,
Andy.

Ok, latest update from this morning. If I power up just one of any of the three fuses that it says have failed (6, 7, 17) using an external 12v supply (taken from one of the three power posts either side of the under seat fusebox) then all three circuits power up. However, even when all three are powered up I still get the gearbox fault once the engine is started (not on when the ignition is on, only when the engine is fired up. When it is just the ignition I get the gear selector indicator on the dash (D,N,R,etc) but once the engine is started it goes away and it gives the gearbox fault message and goes into limp home mode - 3rd gear only). So, do people think I am still right in thinking there is a fault within the BECM on these three circuits?
I need to figure this out and get it rectified ASAP or I am at risk of burning the damned thing!
Cheers,
Andy.

Gear box fault message is often the sign of low battery voltage.

I'd try running a supply to all three inputs, even if it's just jumpers from one to another. 'Something' might be switching inside the BECM when the engine starts and shutting one of the circuits off from your one input. There must be a reason for the three inputs.

Brand new battery Datatek and it's not just the message, it's the full limp home mode. I've tried it with just the one feed and equally the three feeds, same results Dogsbody but if you look at page 305 of the electrical trouble shooting part for the 1995 Range Rover on the Rave CD you'll see the circuit that all three fuses take power from and it's all on a common power feed, just that there is relay 10 inside the BECM in the fuse 17 circuit.
Cheers,
Andy.

So, can anyone advise if I'd also need to change the gearbox ecu if I changed the BECM, Engine ECU and Keyfob (changing the blade to the existing one allowing me to ue the original door locks and ignition)?
Cheers,
Andy.