[Engine] ECU, sensor, wiring??

[mkp2963]

Hello all,
I'm having problems with my 2.0hdi multispace 04 reg. First fault, engine stalled and failed to start, diagnosed as engine speed sensor. Replace and ran for approx. 4 wks. Same fault, this time crankshaft sensor, replace and ran for another few weeks. Same fault again, this time sent ecu away for checking, no faults found. Garage had car for 2 wks of testing, they also checked ecu, no faults found. Finally replaced ecu with another unit. Car ran for another few wks. Same fault, another cam shaft sensor replaced. Car ran for a wk, same fault! I have no hair or money left! Any ideas?

[JohnM]

I would check the engine wiring from the sensors and to the ECU for splits or chafing especially where it is near to the engine and check for poor connections. Very frustrating.

[Ol'Jeffers]

Agree!! A damaged wiring harness will give you random faults.

[addo]

First things first. I'd check the alternator and battery, you need to load test the battery for proper information on its health. The alternator has to have its output assessed by looking at the voltage "wave" as a blown rectifier diode or faulty regulator will give an ECU pink fits.

When you know the voltage supplies are good and steady, some time with a "Lexia" factory diagnostic tool is the safe option. Also, if you test all the engine harness with a multimeter you may find damage from crushing or corrosion. Some motors do sneaky things like push antifreeze up the wires so the ECU rots internally.