Thread: MAF problem - need diagnostic help...

Usually when sensors go bad (or unpluged) they read 99 on the scanner.

I know this for a fact that the iac and the map does.

On a thread from another forum, I learned that there should be 12 V plus going to the MAF:

Pink = Batt +
White/Black = Ground
Yellow = voltage out

Well, the white/black is a good ground, but I'm getting no voltage to the pink wire. I'm thinking this is the root of my problem.

Anyone know why that 12 V source would all of a sudden go bad?
Anyone know if anything else is on that 12 V circuit?
Anyone know if the computer supplies voltage or the key/ignition circuit does?

Any help greatly appreciated.

Thanks...Boatman.

This is starting to become clearer. Went through the wiring diagram and found that the MAF and Evap purge solenoid both share the same "pink wire" 12 V source. And my car is throwing both MAF and Evap codes. It's got to be the 12 V source.

Wiring diagram says that the source is the "Underhood Electrical Center 1". But is does not show that the source from the PCM is fused, just that is passes through this box.

Anyone know if it's fused?

Anyone know where the Underhood Electrical Center 1 is?

Thanks...Boatman.