P2122: Throttle/Pedal Position Sensor/Switch "D" Circuit Low Input

Is your scanner showing P2122?
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P2122: Throttle/Pedal Position Sensor/Switch "D" Circuit Low Input

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What Does The P2122 Code Mean?

A P2122 code means that the the car’s computer has detected that the TPS (throttle position sensor) is reporting too low a voltage. On some vehicles that lower limit is 0.17 – 0.20 volts (V). The “D” refers to a particular circuit, sensor, or area of a particular circuit.

Did you adjust it when you installed it? If the signal value is less than .17V then the PCM sets this code. Could be an open or a short to ground in the signal circuit. Or you may have lost the 5 Volt reference voltage.

P2122 wiring diagram

P2122 wiring diagram

What Are The Symptoms Of The P2122 Code?

Symptoms may include:

  • Rough or low idle
  • Stalling
  • Surging
  • No/little acceleration
  • other symptoms may also be present

What Are The Potential Causes Of The P2122 Code?

A code P2122 may mean that one or more of the following has happened:

  • TPS not mounted securely
  • TPS circuit short to ground or another wire
  • Faulty TPS
  • Damaged computer (PCM)

How Can You Fix The P2122 Code?

Some recommended troubleshooting and repair steps are:

  • Carefully check the throttle position sensor (TPS), wiring connector, and wiring for breaks, etc. Repair or replace as necessary
  • Check the voltage at the TPS (refer to a service manual for your vehicle for specific information). If the voltage is too low that is indicative of a problem. Replace if necessary.
  • If recently replaced the TPS may need to be adjusted. On some vehicles the installation instructions call for the TPS to be properly aligned or adjusted, consult a repair manual for specifics.
  • If there are no symptoms at all, the problem may be intermittent and clearing the code may resolve the issue temporarily. If this is the case then you should definitely check the wiring to be sure it’s not rubbing on anything, grounding, etc. The code may come back.

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> Throttle Position Sensor (generic)
>>> Twippo 372Pcs Waterproof Wire Connectors Kit
>>> INNOVA 5210

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Check This Video For Reference

Reference Sources

Diagnostic Trouble Code (DTC) Charts and Descriptions for P2122 – Page 137.

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