Fuel gauge quit working and pcm gives me p0462 code. If I unplug the sending unit I get p0463 code. I pulled the sending unit out of the tank and measured ohms and got 20-200 with no dead spots in between. With the sending unit in the tank I got 150 ohms at the plug on the tank and at the pcm. I also did the cluster test by holding down the trip reset button and cluster works fine. Cluster and sending unit appear to be good so could pcm be the problem?

 

dont be cheap replace the pcm

 

You don't say what year of truck and I don't know if that matters,I don't think the PCM has anything to do with fuel gauge.

Floyd

 

Well on 2nd gen 12v and 24v the sender sends ohms to the pcm then the pcm turns it into an algorithm that is sent to the cluster and comes out as fuel level. They did this so you didn't have issues with fuel gauge bouncing around giving you inaccurate reading? If you would of read he said it was a certain amount of ohms all the way from the sender at the tank all the way to the pcm? So that, in its self would tell me the pcm does have something to do with it? Just my .02 cents

 

Replacing an ecm is an expensive fix for a bad fuel gauge.

I'd look at the sender again and make sure the resistance is within range. There is a lot of threads on bad senders for the fuel gauge.

The code is new to me. Most guys just r/r the sender when the gauge gives up. If the ecm is the culprit you are looking at around a grand IIRC.