Thread: Cooling Fans Always Running

I'm really pulling my hair out over this issue. I cannot figure it out. No matter what, the both cooling fans start and run at full speed a few seconds after the car is started. They never turn off. Doesn't matter if HVAC is on or off. The fans do not turn on unless the engine is running.

There's no hackery in the car, no jumpered relays, nothing like that.

I searched around some, and someone suggested the Coolant Temp Sensor, but I don't see any odd readings or behavior, it all appears to be functioning correctly. The fan temps in the tune are correct.

Any other ideas anyone can think of? Pretty sure this was happening with a different PCM as well, it's been happening for some time now.

Strangely enough the coolant key off feature works perfectly per the temperature set in the tune.

Well after reading reviews on AAP's website, it looks like it might be related to the BWD temp sensor in the car.. I had to install a new one when I broke the one in the old LIM during the Gen V swap..

Guess I'll be hitting up the dealer tomorrow. If they want $Texas, Amazon has them pretty cheap.

Well, the coolant temp sensor was not the problem.

The issue ended up being the PCM. Not the tune.. the actual, physical PCM. That's the second PCM I've had fail in a totally bizarre way.