Join Date: Apr 2019
Ryan Krizan is offline
No power to fuel relay, ECM issues?
I've got an issue with my 2000 S10 with a 2.2L in it. It drove home just fine on Wednesday night after I filled up the tank. Parked it, tried to start it Thursday morning to head to work, and it would not start. It cranks just fine, but will not fire, no kick, no backfire, nothing.
The fuel pump I replaced with an AC Delco unit 3 years ago. I listened for it to run for the 2 second kick when I roll the key on, I get nothing. So I checked to see if my relay was clicking, and got nothing. I tested the relay, and it tested OK. I swapped out another relay just to be sure (used my horn relay) and still got nothing. Using a volt meter I checked the voltage to the relay using the diagnostic port along side the relay, and got .348 volts continuous when the key is on. No 12 volt for 2 seconds at all, but a continuous .348 volts. I checked the ECM-B fuse, it's fine. Voltage to the fuse was a bit low, but that's because the battery was only at 11.9 volts after a bunch of cranking and testing. So I broke out my OBD-2 scan tool to scan the ECM, and it would not communicate with the ECM. I tried another scan tool, and it too would not communicate. I checked to make sure I had power to the OBD-2 plug, and I do, just no communication from the ECM.
Now, at this point, it's worth pointing out I had an ECM failure on this pickup before, about 8 years ago. 2 of the drivers for the fuel injection went out on the original ECM, and after a noid test I replaced the ECM with a remanufactured ECM from NAPA (over 200 dollars), and the problem was solved.
So at this point, I'm assuming this reman ECU has failed since I can't get any scan tool to communicate with it, but I wanted to ask here before I spend more money, and get some insight from the guys that really know these trucks. It's been a great truck. 302,000 miles and counting, and I haven't had to do much to it! I originally got it with intentions on stuffing a v8 under the hood, but after driving it awhile, I've decided to leave this truck alone and get another truck for a v8 swap.