Hello everyone.
prior to purchasing my 2003 diesel ZT last November I had found this forum whilst trying to educate myself about potential problems to look out for.
Having learned about the plenum issue I made it a point to check my drains with every wash. I would pour some water down the side drains and feel confident as I watched it all came out from under the car. Little did I know how naive I was being as I thought that this was what was being referred to and never checked the middle drain, under the ECU.
A few days ago my car lost power during a drive. After coasting to a safe parking spot, I tried restarting the car. Turning the key would crank the starter confidently but alas the car would not start. Had I not refueled earlier on I would have suspected that I ran out of diesel.
I noticed that I no longer heard the whine of the diesel pump when turning the ignition on. Theorising that it might be an electrical problem, I fiddled around with the fuses next to the battery, and tried turning the key again. To my surprise, the car started!
Alas, the happiness provided by my newfound electrical genius was short lived as the car turned off again within a few seconds. Another fiddle with the fuses let me start it up again, only to have it turn off once more after roughly the same amount of time. No amount of further prodding to the fuses and relays led to the car starting again, so I had to have it towed to the garage, defeated and disheartened.
I'll try to relay the troubleshooting steps that my mechanic described as well as I can:
He first tested the in-tank fuel pump. Supplying a direct charge made it turn however no fuel was reaching the engine bay before the high pressure pump. It may be of importance to mention that (I believe that) he noticed that when the ignition was off the fuel would arrive into the engine bay, but with the ignition, it wouldn't.
Computer diagnostics apparently gave nonsensical error messages consisting of a string of numbers rather than the usual letter followed by a number.
Upon accessing the ECU box he saw that there was water beneath it. A corner of the ECU box shows a water mark (diagonal lines on lower left corner):
The ECU itself looks like this (doesn't look bad):
Close-ups of lower-left corner:
There seems to be some mineral build-up along some of the traces. To my beginner electronics-hobbyist eyes it looks like the only components in this corner are resistors, diodes and what seem like transistors. Would these have been damaged upon contact with water, or would shorting these have caused damage further up-field?
Would this explain the fuel pump issue or could it be caused by something else? What about the strange error messages? Have I fried my ECU? Should I try cleaning with denatured alcohol?
Thanks to this forum I already repaired the leaking boot, solved a coolant leak issue that turned out to be broken O-rings, and I also replaced 3 rusted door trim panels with replacements from Rimmer Bros.
Losing use of the car to this is bumming me out.
Any advice would be very much appreciated.
Cheers