I have a 2002 f150 with the 4.6L Windsor motor in it. My engine is running fine and cool, but the gage on my dashboard is reading nothing, hence tripping the idiot light. While not a big deal I would like to fix this, I know I have a sending unit on the cylinder head itself, but I am also supposed to have one on the intake according to my chilton manual right beside the alternator. I simply cannot find it, and wondered if anyone else had the same problems at all. Thanks for your guys time, any help is greatly appreciated.

 

The PCM sends the signal to your gauge with input it receives from the cylinder head temperature sensor, normally this requires scanning for codes and following a flow chart to determine the problem, however, I have personally seen all it takes to fix the issue is to disconnect the PCM connector and reseating it.

You should be able to do this with minimal trouble as the PCM is located top of the firewall under the hood. 104 pin connector. It either has a bolt in the center of it or flip lock levers, I don't remember which.

If that proves ineffective you will want to pull codes and see what if any are stored.

 

Thank you very much for the response, this however still does not solve the problem. I already had pulled the codes, and none are stored. I pulled that connector and cleaned it using the connector spray, let it all dry well and then put it all back together. When I turn the truck on the gauge will register for about 5 seconds, and then shuts off as completely bottoms off. I would really like to get this problem fixed if possible. Anyone have anymore suggestions?

 

It would make sense to me that this truck would have two sending units, with no codes being stored. I just need to try and locate it. I think this weekend I am going to pull my intake off and see if there is anything. If I can't find anything at least I can just change that cht while I am in there and see if that helps....

 

If the CHT sensor was bad you would absolutely have a code and your truck would likely run rough, I'm beginning to think you have a gauge problem, I don't know for certain if you can change the gauge because in 1997 when they changed the body style they also went to a non serviceable cluster, we would have to send the whole thing out for repair. Pull the cluster out and check the connector pins for corrosion.