PO122 Code Please Help

[Vince1057]

I just pulled PO122 code from my 2000 Tahoe 4.8l 4X4. The book says it is a:

Throttle/Pedal Position Sensor/Switch A Circuit Low input.

Does anyone know what may have caused this code and how to fix it. Any input is appreciated.

[777stickman]

As stated the code is caused by low voltage sensed at the TPS(Throttle Position Sensor) by the VCM. Need to get a scanner on it that can read TPS voltage from idle to WOT. This test needs to be done with the engine off and the key in the run position. The idle position voltage should be around 0.45-0.85 volts. The voltage should smoothly increase as you push the pedal to over 4.5 volts at WOT. If this doesn't happen then it's probably the TPS gone bad. The TPS is located on the throttle body and is driven by the throttle cable input.

Other problems could be wiring. Chaffed or broken wires.

PS: The post you did in the Suburban forum was almost 3 years old so I doubt you'll be getting an answer from there. It's good to check post dates before posting.

[Vince1057]

Thanks for the reply.
I'm going to bring it in, I'm not comfortable with wiring issues. If it was just a simple replace sensor fix I can handle that. Would replacing the TPS fix the problem?
Thanks again

[MT-2500]

Originally Posted by Vince1057

Thanks for the reply.
I'm going to bring it in, I'm not comfortable with wiring issues. If it was just a simple replace sensor fix I can handle that. Would replacing the TPS fix the problem?
Thanks again

Code does not say replace sensor .
It says check it out.

First as said check the voltage reading with a volt/ohm meter.
A lot of tps sensor problems can be the wiring or plug in on it.

If the voltage reading is good chances are the wiring is good.
But also you need to see what it is reading to and in the computer.

A volt/ohm meter reading will give you the voltage readings but will not catch a glitz or drop out in the tps sensor.

The only true TPS sensor test is with a labscope.
MT