The other day, I got a code 34, and it turned out my burnoff function was not working. So I replaced my maf burnoff, and power relays, along with a new oil pressure switch.
I also checked for continuity on the burnoff control wire from the ecm to the relay, and it's fine.
Now it sometimes burns off, and sometimes doesn't.
BTW, does anyone know how long the maf is supposed to burn off for? When I hear the relay click, it doesn't sound like it stays on for long.
Thanks for any help...

 

The MAF burnoff circuit will operate the hot wire at full voltage until the ECM receives a 5.0V signal from the MAF electronics. The MAF electronics produce an output signal to the ECM based upon the current applied to the hot wire. Since there is no air flowing while the MAF burnoff cycle is underway, there is no air flowing to cool the hot wire. It becomes incandescent and flakes off any accumulated debris, contamination, film, oil, etcetera.

That cycle may take 20 seconds,or may only take 3-5 seconds.

 

Thanks for your reply. Update: The burnoff relay only clicks on for less than 1 sec. and even then only produces 2V on the signal wire - even if I manually engage the relay, and no matter how long it's on. The power wire is getting 12V at the same time too.

 

Ok. every component tests out good, all connections and grounds are all good, but the computer just won't send the burnoff signal for more than about 1/2 - 3/4 sec. Am I correct iin assuming the computer is the culprit ?

 

Maybe not. Is the ECM storing a code 36?

 

Code 36 is for the Burn-off function, which is what your were trying to diagnose, but in your first post, you said you had a Code 34 which is something else with the MAF.

 

No code 36, but a code 34, which I thought was due to the burnoff not working properly. I get the code ( and the car runs like garbage) about every 3 times I start the car.

 

I'd be checking the MAF power relay and not losing sleep over the burn off function just yet.