i have a cel, but there is no codes. i had a header and downpipe on my car for about a month, so i knew there was a code for the secondary air injection. i put the stock header and downpipe back on monday on and cleared the codes. but the check engine light keeps on coming on and there is no codes. will it go away after a number of key starts? help!

 

Unplug your battery. That will clear it. If it comes back then something is up.

Edit: I guess I missed the part where you said you already had it cleared. That is strange there is no code.. Have you tried different code readers?

 

ya thats strange that your cel light would come on but no codes. how are you checking for the codes though because bcm codes will set a cel as well. so if your only scanning the ecm and there is no problems with the ecm side of things then there would be no code. try scanning the bcm and the chassis system and see if there are any codes in there.

 

the autozone code reader lol

 

ya i don't know what that one all scans. some scanners only scan the ecm as the bcm and chassis system are kinda secondary in comparison. are you taking it to autozone and having them scan it?

 

yeah autozone scaned it

i unplugged the battery for about 2 hours. started the car and it was off. i went to school, takes about 30 min to get there, no cel. when i left school, i started my car and it was off for about 3 seconds then it came on. any ideas?

 

yeah. dont worry about it until there is a code. i had a crack in my IM and had a lean code. patched up the mani and it took about 30 miles for the light to turn off.

give it some time

 

its been on since monday and i drove over 200 miles since. im trying to get rid of the car and i cant till this stupid cel goes off

 

bump HELP!

 

take it to the dealer. you could have an electrical problem or short somewhere.

It shouldn't be on without codes.

 

You car hates you jon..lol.

 

i gotta make a appointment for the new steering rack, ill have them look at this too

it really does lol. it gives me problems now right before im trying to trade it in

 

i still think that the autozone guy is only scanning the ecm and not scanning the bcm or the ebcm which can throw codes as well. so if there's nothing in the ecm then that means there's something in the other systems

 

Only the Tech II scanner can read the BCM. There is no possibility of the Autozone scanner reading the codes from the BCM. And the BCM will not throw a CEL afaik. The BCM has it's own displays, i.e ABS light, E-Brake light, and the DIC.

 

Did u delete the SAI? or did you find a header that accomidated it?

 

well that clears up the autozone scanner issue. but i know the bcm will throw codes such as radio codes, and a few others (not many) abs and such are controlled through the ebcm (electronic brake control module)

 

i just used a regular header, but now i have my sai header back on

 

the BDM throws codes, yes, but the only way to read them afaik is at the dealer with a TechII. It's throws low voltage coeds etc regarding the radio, the wheel speed sensors, trunk ajar sensors, etc. etc. It knows when you jump the car and when you remove the battery.

 

will i know how a tech 2 works. i worked for a dealer for 4 years. i just didn't know that autozone and other parts stores readers couldn't read them.

 

oop. Sorry boss. Takes a special scanner to read BCM. Most are manufacturer specific as far as i know.

 

awesome and don't sweat it. i still think thats what the OP's problem is, since the CEL light won't come on for no reason.

 

Any good scanner like a modis or master tech or a solus pro can read gm bcm PCM and chassis systems not just a tech two

**** I can read gm bcm and chassis systems with a ford ngs scanner gm has one of the simplest operating systems when it comes to diagnostics