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check engine soon light for emission problems? 2002 AV

vett82

Full Member
Joined
Jul 20, 2009
Messages
47
Hey,
does the check engine soon light post at the dash for emission problems (bad o2 sensor,bad fuel mix, etc., etc.), or is that another light that post and says something different. Auto zone's code reader couldn't pick up any faults on the computer but my "check engine soon light" is posted on the dash.
 
The SES light posts for any multitude of reasons. Fuel issues, sensor issues, clogged/non-functional evap return system, low battery, you name it and the computer probably has a code for it. There are literally hundreds of codes if you ever see the actual printed list. Sometimes only one of the really comprehensive, expensive code readers will pick up certain codes. Cheapy readers are of marginal use.

Also, don't go out buying parts "per code." A numbered code relating to "02 Sensor" for example, can mean any number of a hundred things other than the 02 sensor. You most often need more comprehensive diagnostics wiht actual tesst equipment than what the codes indicate. Think of codes as "starting points."

Try another facility or auto parts store for a code reader effort, maybe even the chevy dealer. Or try to go to an ASE certified shop; they are likely to have a more suitable comprehensive reader. There should be a code if the SES light is on.

If you can post a code here, there are folks who can chime in and tell you that "code #xxxxx" usually means you have a bad ______. Some codes are very familiar common problems to us; other codes are not.
 
interesting thing just occurred on the vehicle. I had read online that there was a difference between "check engine soon" light and "service engine soon" light.

According to the read, it said the "service engine soon" light was for maintenance issues based on mileage and to clear it you disconnected the negative terminal for 5 minutes.

So...I did this and the "service engine soon" light went away but immediately the "service engine soon" light posted and is not going away!! So I went to Auto zone and they said their code reader would not communicate and acknowledge the AV computer. So then I went to Advance auto parts, but they had the same experience with non-acknowledgement. Any ideas?
 
check fuses for cig lighter as it probably blown and hence they cannot read code
 
No that's working fine because I've been charging my cell phone through that jack.
 
Are you charging your cell phone through the "Cigar Lighter", or one of the "Auxiliary Power Outlets"? There's a difference. And, different fuses.
"Cigar Lighter" is the far right outlet (with the lighter plugged in), Fuse #47 "Cigar" in the Underhood Fuse Block.
"Auxiliary Power Outlet"s are the 2 on the left. They run through Fuse #41 "AUX POWER", in the Underhood Fuse Block.

HTH,
EJ
 
Av-n-Taz said:
Are you charging your cell phone through the "Cigar Lighter", or one of the "Auxiliary Power Outlets"? There's a difference. And, different fuses.
"Cigar Lighter" is the far right outlet (with the lighter plugged in), Fuse #47 "Cigar" in the Underhood Fuse Block.
"Auxiliary Power Outlet"s are the 2 on the left. They run through Fuse #41 "AUX POWER", in the Underhood Fuse Block.

HTH,
EJ

you were right. fuse was blown. took it back to autozone for a check and the code turned out to be po440. I knew that's what it would be. I had an 04 av once and never got the po440 code resolved. I hate those annoying po440's.
 
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