P0120 P1120 Fault but not the sensors

Hello,

Ive had an intermittent fault for the last year or so where my throttle peddle would die and the check engine light would come on showing the P0120 P1120 Faults. We would turn the truck off and back on and it would drive again. I replaced the pedal position sensor and throttle position sensor as per the instructions in the Haynes manual and used my scan tool to set the tps to 15%. Truck started up and off I went on a test drive, the first couple of times i accelerated it kinda stuttered above 3000rpm and then it went back to limp mode and now its stuck there. I have noticed that my scanner tool now show throttle at 0% and i can't pull any voltage off any of those sensor wire. Im looking at the electrical diagram and see that these sensors are tied into the Vapor Pressure sensor too could that be affecting it? Is pin 2 (VC) the wire i should be getting voltage from? any help would be greatly appreciated.

Kane

 

Just got mine back on the road and had this happen on the way back from a shop so I don't have a solution but curious to hear how you solve the issue.

 

p0120 is a tps excessively low circuit voltage related dtc. p1120 is a tps out of range dtc. Since you replaced tps, was it an oem? or an aftermarket?

 

I traced it back it a bad crimp in the connecter between the 2 pieces of wiring loom that head towards the the actual tps not the accelerator pedal position sensor, there should be 5V on the green-black wire as it meets the tps if not look back until you find it. Jiggle the wires a-bit because my fault was intermittent. I believe there should be ground on the green-white wire too. Returned both tps and apps to the store and trucks running smooth as silk

 

5 v ref , ground and signal if its 3 wire.

 

Once you ID’d the spot with bad crimp, how did you fix? I faced a similar issue. Changed out entire throttle body and still get P1120, so I’m thinking wiring as well.

 

If anyone can point me to a good YouTube on this process for checking the wiring like this, I would appreciate it. I am having a nearly identical problem to what you described. Just need some tips about the process. Thx.