Well I have been trying to get this fixed for over a year now. I am at my wits end and am literally about to torch the truck. I have tried 4 different sensors with no avail. I get the 5 volts on the VREF wire but nothing on the other two when I hook the leads from my multimeter to the two as described in this link. http://fordfuelinjection.com/?p=30

When I pull the code off its for the tps sensor and thats the only code. I have to emissions it but I cant get the CEL to stay off so its going to fail. Any ideas? You guys are my last hope.........

 

Post the TPS code Number.

How are you trying to measure/probe for the TPS signal return voltage????

 

you've got reference voltage. those other wires are send and return feedback to the ecm. or signal wires. but without a scanner that you veiw the data while its runnin' is pretty hard to diagnose. you can have a bad one and not know it. and TPS'S are tricky to catch. have you tested the wiring? as in disconnect the harness from the ecm and your sensor and do a continuity test on the harness itself. and see if you have a broken wire. and check your grounds at the frame and body and engine. a dirty ground will cause problems as well. and donnot run resistance thru the ecm you will ruin it.
you have to rule out all other possibles. i have seen ECM'S go south due to moisture. and they do all kinds of weird stuff.

 

It is a p0121 code.... Some good ideas.... the only thing I haven't tried is a continuity test. Do you know which wires at the ecm they are???

 

no i don't! sorry!

 

The P0121 code says that the TPS voltage does not agree with the MAF sensor.

Seeing as how you've tried so many new TPS sensors, thats not likely the problem, so I like Ford Rangers idea to pull the computers firewall connector & do a continuity test on the TPS wiring.
You could do a search for the computers pin connection, I think i've recently seen it posted on this forum.
Or just look for the same color coded wire.

If the continuity checks out ok & to rule out Murphys Law, check the TPS resistance with an analog meter, it should read 3-4K ohms at closed throttle & should smoothly change, no jumps or discontinuity, to about 350 ohms at WOT.

If that checks out ok, reconnect the TPS electrical connector & back probe the center TP SIG wire with the test meters + probe & the SIG RTN wire with the testmeters - probe. (the sig rtn wire is on the opposite side of the TPS connector from the 5 volt ref contact/wire).

At KOEO & closed throttle, you should have 0.5-1.0 volt between the TPS SIG & SIG RTN wires. At WOT you should have 4-5.0 volts on those leads.

If you have the proper 5 volt ref to the TPS, but don't have those measured values, then suspect the TPS.

If all that checks out & with the code you have, saying that the TPS voltage doesn't agree with the MAF sensor, maybe suspect a dirty MAF sensor!!!!
So remove & clean the MAF sensor with CRC MAF Spray Cleaner & see how it goes.

A bunch more thoughts for consideration, Let us know how it goes.

 

no sir,
there shouldn't be any dead spots threwout the throttle climb. with a meter. but if you can get you hands on a scanner that would be a big help. because you can look at the data. that code will cause your automatic tranny to shift funny.
i like PAWS idea as well. do that test as well. just so you can rule out and find the problem and get it repaired so you can take the truck thru DEQ.
and do let us know what the progress is please.