Capt301Ret
Newbie
I have a 98 k2500 with the 5.7. Two weeks ago the truck started running bad. First noticed it would shut down for a split second, mostly during light throttle. I would describe it more like it skipping a beat. And the idle was rough. It happened while towing my camper through a state forest in MD which really put a strain due to the hills and it was running hot. Not overheating though. Same thing the next morning when it was cool. Checked for error codes, had a P0102, MAF sensor. Checked for power and ground, they were OK. Didn't have a meter to check the output, but it was only a few months old and covered by warranty so I replaced it. Same thing. Checked for continuity on the signal wire and it was OK between the sensor and the PCM. Fuel economy also tanked. This continued the next day. Through the catskills on the third day, it started pinging really bad. I was down to 3/4 of a tank, I filled up and it continued, third tank of gas and it still was pinging. For two years I've towed this camper all over the country and never had a ping/knock problem.
I checked for codes with an OTC scanner and got a Camshaft position sensor low code. Distributor is also fairly new. I also now have a P0122 TPS error. I had Autozone check codes, only the P0102 and P0122, no CPS code. I did get a multi-meter that read hz and I have a signal that varies with rpm to the PCM, so I don't think it's a bad MAF or wiring problem.
I have a tablet with Torque always displaying stats. I noticed that my Load, MAF, and IAC all read 0 when I used to get readings.
I think the PCM has failed, but a mechanic friend suggested that with the CPS bad, it could be in some kind of default mode and running real rich. But that doesn't explain all the sensor failure codes and 0 readings.
Any thoughts before I replace the PCM?
I checked for codes with an OTC scanner and got a Camshaft position sensor low code. Distributor is also fairly new. I also now have a P0122 TPS error. I had Autozone check codes, only the P0102 and P0122, no CPS code. I did get a multi-meter that read hz and I have a signal that varies with rpm to the PCM, so I don't think it's a bad MAF or wiring problem.
I have a tablet with Torque always displaying stats. I noticed that my Load, MAF, and IAC all read 0 when I used to get readings.
I think the PCM has failed, but a mechanic friend suggested that with the CPS bad, it could be in some kind of default mode and running real rich. But that doesn't explain all the sensor failure codes and 0 readings.
Any thoughts before I replace the PCM?
