What is a p0122 trouble code and what to do to fix it on a 2000 Chevy cavalier?

Answer 1

Throttle Position Sensor circuit low input. Testing procedure is complicated,but I would say the sensor is not putting out enough current to the computer so it don't know if you are wide open or sitting at a red light.. They are easy to replace but hard on the pocket. There should be plenty of them in a salvage yard cheep. Or get a whole throttle body on eBay for even less. But I would replace the TPS, its rare but they do go bad.

Update....

1. With the engine OFF and the ignition ON , check the voltage at the signal return circuit of the TP sensor by carefully backprobing the connector
2. Voltage should be between using a DVOM,,,(aka...Volt Meter) 0.2 and 1.4 volts at idle.
3. Slowly move the throttle pulley to the wide open throttle (WOT) position and watch the voltage on the DVOM. The voltage should slowly rise to slightly less than 4.8v at Wide Open Throttle (WOT).
4. If no voltage is present, check the wiring harness for supply voltage (5.0v) and ground (0.3v or less), by referring to your corresponding wiring guide. If supply voltage and ground are present, but no output voltage from TP, replace the TP sensor. If supply voltage and ground do not meet specifications, make necessary repairs to the harness or PCM.
5. Erase the trouble code with your "handheld".Don't have a "handheld"..?... Try erase all memory of the computer by pulling the underhood fuse marked "ICM" for about 30sec. ,It should be a 20amp fuse... it may run a little rough at first (10 sec. max)until it relearns the things it needs to know.