Re: My new "old" truck with some CEL
Code 18- There's a plug near the distributor that may be unplugged. It's grey.
Code 21-Engine coolant temperature voltage is out side the range of 0.2 to 4.84 volts. PCM pin #7, wire color is Light Green/Yellow. Possible bad sensor.
Code 31-EGR valve position (EVP) sensor signal is below 0.20 volts. PCM pin #27, wire color is Brown/Light Green. Possible bad sensor.
Code 41-Maybe it wasn't run long enough to heat it up?
Code 85-Canister purge solenoid did not respond.The self test looks for battery voltage during the solenoid off command and voltage under 1 volt during the solenoid on command issued during the self test. Solenoid resistance is 40-90 Ω. PCM pin #31, wire color is Grey-Yellow.