I'm in the process of doing over the valve cover plug wires and my ALDL cable came in today. I hooked it up to the car and turned key on engine off and it did not pull any codes. I cannot start it right now because I haven't crimped all of my plug wires yet. Do I need the engine to start to start getting values off of the PCM?

Thanks,
James

 

With key on engine off Freescan should be reading the engine sensors and parameters out of the PCM. The PCM puts out a couple dummy readings with the engine off such as RPM = 50 and desired idle speed reads 3187. The rest are actual readings..MAP should be near 99 KPA (baro pressure), all BLM's s/b 128, TPS=0, TPS voltage s/b accurate, coolant temp, IAT (MAT) and battery voltage s/b accurate, MAS air flow s/b = 0. Sometimes my O2's read 700-800 MV depends on O2 temp and how long key is on. It's good practice to check them in this condition to verify the sensor operation before starting the engine.

 

onefastmx5:
"it did not pull any codes"
If you mean stored error codes, it should have found them if there were any. If you disconnected the battery before doing your work, I think the PCM loses any stored codes if power to it is interrupted.

 

Update: Freescan sucks. It would act like it was communicating with the PCM and was showing no data at all. I played with it for like 10 minutes and gave up. Downloaded TTS datamaster to the laptop and instantaneously got results. Pulled a code 13 -left o2 sensor, going to buy one tonite. Erased code, will see if it comes back.