So to get started I have a 97 Camaro Z28 with the 5.7 L LT1 engine. I just recently began having problems with the car overheating 240+ range.

I narrowed down my problem to be the cooling fans. The fans are not coming on when the cars temperature gets to operating range (185-220).

The fans do come on when I turn my A/C on so the fans are good.

I tested all three fan relays each on of them tested good.

I hooked up the OBD II reader to the car and got good reading on temperature from the temp sensor in the water pump. The temperature that I got from the OBD II was always within 10 degrees of the temp gauge on the dash which is controlled by another temp sensor.

So then I removed my PCM and did a continuity check on the wires that run from the PCM to the fuse / relay box. And both wires check good (Drk Green / Drk Blue)

The way I see it this leaves me with only one option left. My PCM has gone bad. The fans work, the fan circuit is good, the temp sensor is good, and the wiring to the pcm is good!!!

I am hoping that someone here maybe can see something I may have missed and if not then support my bad PCM idea. Thank you for any and all help!

-Rob

 

Are you sure the temp sensor is working? Fans don't kick on until high temps. You could be havin a low voltage failure with your temp sensor. Try running your car until it's warm then take a volt meter to check it.

 

The fans are set to come on when the coolant is above 220 degrees.