jw9424

Well the ECM is back from ACS. There are stickers on this thing saying the truck has a short in it. We’ve already checked for a short to ground on the 5v circuit and didn’t find one. Something else we need to check? We did however end up having to have the alternator rebuilt after getting it checked during this process. Is it possible that bad alternator took out the ECM 5v reference?

Update: Everything we tested seemed to point towards a cam position sensor but after swapping it out twice, the voltage was never right after plugging in the cam sensor. Had an electrical specialist look at it and they were able to confirm it’s the ECM causing this. Said the vref signal was not supplying enough current with all sensors plugged in. They quoted me north of $2k to fix it. I see on here guys have used Autocomputerspecialist.com with success having their ECM repaired so unless someone has a better idea, I’ll be sending mine off and hope for the best.

I was afraid of that. Thanks for the reply

Truck runs but not well. Tach does not work. Will not build more than 10PSI of boost. CEL is on. Has 7 codes total but seems that most if not all can be attributed to that 5V required for the WIF, Oil pressure, cam position and map sensor. Codes are P1693, P0236, P0522, P0341, P1488, P0342 and P1295.

Can the cam position sensor be tested with a DMM for the correct resistance? If so, what should the value be? This is on an 01 2500 auto. Trying to track down what's causing a P1488 code among others. The trouble-shooting procedure tells us to replace the cam position sensor but we've done that a couple times. Any help would be appreciated. Thanks.