I just got my car a few weeks ago, and when i bought it the mass air flow sensor was bad. I replaced it and now after the car sits over night, the battery is dead the next morning. The battery is brand new, i replaced it as well. I did a search on here and came across a similar situation, said that if the relay for the MAF was bad that it would cause the MAF to run constantly causing the battery to die. IF this is the case, which relay is for the MAF?? And also, how can i tell if i fried my new MAF sensor??

 

Either relay beign energized constantly (or having contacts stuck) can drain the battery, although the burn-off relay would do it faster. You can either:

1. Meter through the contacts to determine if they are stuck or arcedl
2. Remove, open, and inspect the relays;
3. Or replace the burn-off relay. If the problem still occurs after replacing the burn-off, use the old relay to replace the MAF power relay.

There is also the possibility that the output transistor in the ECM has an E-C short and is keeping a relay energized constantly, or that the wire harness has problems, and is doing the same thing. I'd start with the relays themselves, since they are the most likely candidates for "Troublemaker of the Week" and are the easiest.

 

well to narrow it down to the MAF when you shut the car off for the night just unplug the MAF and see if it starts the next day. if it starts you know it's the MAF and if it doesn't then you know know it's something else.

 

Yea, i have already narrowed it down to that, i just unplugged it all together and now its starts fine of the mornings