Checking Codes

[Bonnell]

I have a stock '88 coupe. It has headers but I supoose that is still stock?

Should I use the simple paper clip method to test for codes periodically or will the SES light always come on if a code is thrown?

Thanks.

 

[Hrtbeat1]

Ses

I would think that the ECM would trigger the SES light for any code ... unless the bulb is burned out.

I check my 90 every now and then just to see.

C ya

 

[vader86]

If you notice your engine is running rough or that your fuel mileage has suddenly dropped, which indicate O2 sensor and/or MAF sensor/relay failure, it may not trigger an SES light. Not always.

Otherwise the ECM triggers the SES when it senses something wrong.

 

[C4CRAZY787]

I would think that the ECM would trigger the SES light for any code ... unless the bulb is burned out.

Yes, and the SES light should allways come on when the key is turned to the on position.

 

[Bonnell]

Thanks for the replies. The SES light does come on during starting. It does not stay on but I simply did not know if it would always come on if there are any codes available. My car seems just a little rough - not much - but the gas milage stays at about 20.5 with mostly highway driving but not long ago it was closer to 22mpg.

 

[86PACER]

http://www.c4vettes.com/ecm.htm

 

[Bonnell]

That is a very informative site. Thanks.