my SES soon light comes on only when idiling, when it comes on, it kicks on my fans too. possible coolant temp sensor??? No fault codes are present at all not even when the light comes on! its a 94 z28. anybody diagnose anything similiar?

 

Many codes cause the fans to come on with the SES light, not just the coolant temp sensor.

How are you scanning it? If you aren't getting codes you aren't doing it correctly.

 

I have been scanning it with my scanner. obd1 scanner. its saying no active or logged codes or present.

 

Highly unusual. Has the scanner picked up codes on the car before?

Check the fuse for the AIR pump. That's a common code that turns on the fans.

 

I haven't had the scanner pull codes off that car car before, but i've done diffrent vehicles with obd1 and 2, thanks i'll check that out!

 

Does your scanner need a power source? The port on the '94 doesn't supply power.

I had an Autoxray once that "failed to communicate". Turns out there was an internal flaw in the scan tool. I was allowed to turn it in for the newer model, which was a much better unit. I did have to pay $100 because I wanted the extra cables and enhanced mode. Still a good deal.

 

I'm pretty sure my scanner is fine, but i'm thinking of taking it too a shop too pull codes, I have a can obd1 and obd2 scanner. Its the same one as snap on and many auto parts stores have.

 

You just can't beat a simple Auto Xray OBD-I scanner, a ScanMaster LT1, or the TTS DataMaster, Freescan, and pcmcomm scanning software for pulling codes.