I am receiving 5 volts on the TPS signal wire. I cut the wire near the PCM to and confirmed that it is coming from the PCM. I just replaced the PCM with remaned one from AutoComputerExchange.com and have the exact same problem. I tried replacing the brake switch and it made no difference. Are there any other sensors that would cause the PCM to send 5 volts out on the signal wire? I have been at this for a couple of weeks now and I am losing my mind...

 

What year truck?

 

Sorry about that, forgot to do the signature. Trying to figure out how to now, but its a 1996 Dodge Ram 2500 A/T 4x4.

 

Ok, I happen to have a 96 FSM, so here goes.

I will attach this info as well.

Your 5V supply goes from pin A17 on the PCM to 1 on the TPS and should be a white wire

Your Signal wire ( the one you say has 5V all the time ) Goes from Pin A23 on the PCM to 2 on the TPS and should be a Dark Blue wire.

Your 5V ground comes form pin A4 on the PCM and goes to 3 on the TPS and should be a Blue/Light Brown wire.

Sound about right?

If so then the only possible source of the constant +5V on the signal is from the PCM internally.

That would be very unusual indeed.

 

You are a little off on the wire colors, the colors you gave are the tracer colors. But other than that everything else sounds and looks right. I have tried using my FSM as well, but haven't be finding it of much help in this particular issue. Does any one know if it is possible to have a sensor go bad causing it start sending voltage down the wrong wire, causing it to show up on my signal wire for the tps?

 

Man, the only possibility would be if it were a Cali smogged truck. They do reference the EGR control module splicing into the signal wire.

It isn't a Cali EGR equipped truck is it?

 

I don't believe that it has California emission standards, I also don't see an EGR tube. Where are they normally located? I called Computer Auto Exchange yesterday and asked them to send me another computer, should be here in the next day or so.

I was wondering if a sensor malfunctioning could cause this? Maybe it is sending voltage backwards through the circuit? I know its a shot in the dark but I am getting desperate here. What is every ones opinion on this theory?

 

If the problem goes away with the TPS unplugged then yes. If you have 5v on the signal wire with the TPS unplugged there is a problem elsewhere.

 

I get the 5v with the wire cut 6-8" away from the PCM. Could it be that I just received another computer with the same problem as mine?

 

The EGR tube runs right over the top of the engine, you can't miss the ugly monstrosity. Also, the air horn is completely different. It's not triangular-shaped, it's just square. I have a 1996 CA truck, EGR deleted.