crazydad

I can't get the above mentioned monitor to set as ready so I can get the car inspected. There are no codes so it's not listing an error. It used to be one of the first ones that would always set. (I have never been able to get the evap sensor to set as ready either which is why I need this one.)

I did the exact procedure desribed in the GM drive cycle. The car has also been driven around 400 miles since we last cleared the codes (dirty MAF issue).

Car is a 2002 Camaro SS with the SLP upgrades. Everything else is stock. Any ideas?

AL SS590 M6

Over my head. Maybe you should ask in the computer/tuning section?

If you want I can move this thread there.

crazydad

Move it if you think it will help. At this point I can't figure it out and am looking for any help whatsoever. Thanks, Steve

Kraest

I'll move it.

bobdec

Not sure if I can help or not.. When you turn on the key the under hood 20a Engine Sensor Fuse supplies +12 V to the four O2 sensor heaters. This allows the O2's to reach operating temp (usually 600* F) faster and the PCM to enter closed loop (AKA: less emissions during open loop) quicker. What the OBD2 heater ready test does is see how fast the O2's heat up by checking the O2 output voltage compared to a fixed time criteria. The test is performed only during a cold start, the coolant temp must be between 40 and 90*F AND the outside temp must be within 10* F of the coolant temp. Bottom line your ready is not setting because the PCM does not think one or more of the O2's voltages is reaching a expected criteria ? fast enough after a cold start. Could be a slow switching O2, open heater in an O2 or a defective heater circuit to the O2(s). Ya probably need a real service manual or someone with more 2002 information to narrow this down.. Maybe someone could chime in..

crazydad

Thanks for moving this post.

Bob, thanks for your response. However, if it had one of those conditions, wouldn't it set some sort of code?

Also, if the OH2 monitor doesn't run, doesn't this prevent other monitors from completing? The only other one not complete is the evap one which never has completed.

bobdec

Monitor tests are not necessary tied to each other. EG the O2 heater test only runs during a COLD start. But the Evap ready test runs during operating criteria. The monitor test failures do not throw codes, but help if you do have a code. In other words since you do not have any DTC's your O2 is reaching 600 degrees and is switching and operating correctly even though the monitor test says the heater is not operating to required criteria. Could be your exhaust is hot enough to keep it @ 600* w/o a heater or something is wrong in the testing circuit/algorithm. I'm sorry I'm talking in general terms here because I personally do not have OBD2 practical experience, nor the shop books to explain how to diagnose this failure on this specific vehicle. Technically I'm getting over my head and I don't want to string you along.