Truck's done this since I've got it, and it's that time of year again that the light will come on and not go off...flickers some, but the grids never quit. That's why they're unplugged right now. Wondering what tells them they can stop cycling. Thanks,

Brian

 

There is a temp sensor somewhere in the intake (on a second gen anyways) that tells the grids if/how long they need to be on.

 

I dont think they are supposed to come on until it gets below 40 degrees but im not sure. The light will always come on though because of the simple light test it does.

 

I was reading a post somewhere...I forget where, but the fella had a similar problem and it turned out to be a dirty IAT sensor. The fella r&r`ed it and cleaned it and no more grid cycling...worth a try in my book.

 

The PCM should shut them off after 5 minutes of cycling no matter how cold the temp sensor is reading. Are you sure they NEVER shut off?

 

Some info on the cycling: Here and here


Den