[Z86Trev]

Parked the car today around 3. Moved it around 730 and the service engine light was on. There were no current codes on my code reader, but in the code history is 78 (number 2 cooling fan). When I clear it it comes right back on. Both cooling fans are on as soon as I start the car. It runs fine, but obviously something is wrong. Any ideas?

 

[DiGGM95]

Try swapping the fan relays in the underhood fuse box, and clear the code.

If the car then throws a code 77, its the relay. If it throws another 78, the secondary fan may be on its way out.

 

[Z86Trev]

I swapped them out, but didnt clear the code. Nothing changed. I will swap em and clear the code tomorrow. I think I have an extra secondary fan laying around so I may throw that in. Its weird, the car actually seemed to be running better than usual tonite which scares me, lol.
Thanks for the help.

 

[Z86Trev]

Dam, did all of the above. no change.

 

[Z86Trev]

Changed the sensor on the front of the water pump. No change. Cleared the codes and then got a code for maf/map sensor. Cleaned the maf, still no change. Changed the map sensor and all is well. BUT, the fans still come right on. No check engine light though. Guess we will see what happens tomorrow.