P38 Diesel ecu - control unit internal fault

So my car had issues, I bought it to an auto electrician, and he diagnosed the large connector under the header tank as the issue and soldered all those wires together.

the car is driving now thankfully.

But 50% of the time when i start the car, it goes into an over-rev condition, where it idles way too high at 3000 RPM.

These are the EDC faults from the nanocom:

(I managed to repair a broken wire the electrician missed, and get rid of the boost error tonight)



I would love some guidance regarding what to try.

I am thinking of swapping the EDC since I have a spare.
I read some threads on here about syncing the edc to the becm, and looked through the nanocom Diesel ECU guide for the P38.
So far as I can gather the procedure goes like so:

1. Locate the 4 digit code thats hard coded into the diesel ecu.
2. Enter that 4 digit code into the BECM
3. Copy the pump calibration settings from the old diesel ecu and copy those to the new ecu

Any and all insight appreciated. I disabled the immobiliser a few weeks ago, not sure if that matters.

Your problem is the CPS losing signal to ECU.

Thanks Wammers. Crankshaft Position Sensor. Will have a read into that.

ned_ said:

Thanks Wammers. Crankshaft Position Sensor. Will have a read into that.

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Whatever you do NOT remove the bracket it bolts to, just remove sensor from bracket. One bolt. If CPS fails ECU uses signal from number four injector that is what gives the high RPM.

Okay, willdo, awesome cool. I have a spare so can try that.

This is the sensor that came out of my driver. These are hard to get back in without damaging.

Just be careful with the bracket on the vehicle.
It sets the air gap at the business end and has a very small tolerance. If that gets put out you need a silly price tool to reset it.

I smeared the hole and the sensor in oil and wriggled it back in with the vice grips.

It did not fix the over-rev issue. The sensor I fitted was from my spares car. I'll buy a new sensor and fit that.

Check then both with a dvm and compare the results, mind you they both could be buggered or good!!

We have had at least one member where it was a break in the wire to the sensor rather than the sensor itself.

Will check the sensors and the wires, cheers guys, appreciate it.