Engine light is on .. code reader wont access codes, is this a wiring problem?

Dennis Mulford

• 1055 Answers
• Posted on Jan 24, 2009

SOURCE: 91 s10 blazer engine surges warm and cold, stalls

tps sencor or maf sencor

SOURCE: P0172 and P0128 Error Code 2003 Trailblazer 4WD

PO172 means that an oxygen sensor in bank 1 detected a rich condition (too little oxygen in the exhaust). I would replace the thermostat first. The computer could be injecting too much fuel because it thinks it never gets to operating temperature. That may keep the light off.

SOURCE: S10 has very high idle when cold and sticks to the gas when warm

you need to replace the throtle body controll sensor. Also you may want to make sure all your linkage from the pedal to the throtle body is cleaned and lubed correctly. While playing in this direct area. Your throtle body is only 4 bolts away. Why not get some carb cleaner and get to know your truck just a litle more.

If this is a carborator, then you need to turn my warmup idle down. there are 2 sets of idles on carborators. the one to warm up the engine, automatic choke or pin settings. Get a Chilton, find out which idles pin is for what. and play a litle bit.

I think you have a throtle body so I would also check the automatic air intake sensor. It could be going bad. Check your filter and make sure its clean.

hope all this helps.

tepfy

SOURCE: PCM Troubleshooting Check light on with no code reader power

You can't jump the connector to get codes on OBD II. (Pre 1996) Try hooking back up you code reader. If it doesn't communicate, check the fuse for the cig lighter. This fuse should also power up the diagnostic plug.

SOURCE: idle out of control.

check all your vacuum hoses and the throttle body itself for a vacuum leaks if the hoses replace as nessasary if to check for throttle body get can of carb cleaner and spray around base of throttle body and sides not in it if idle raises you have a vacuum leak goto a good parts store and ask for a rebuild kit don't goto auto zone or advance they don't carry them