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Ron Z.
Ron Z., - Jeep Tech -
Category: Jeep
Satisfied Customers: 18792
Experience:  18+yrs experience. State Inspector & Jeep Diagnostics/Repair
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How to fix code p0123?

Resolved Question:

How to fix code p0123?

Submitted: 7 years ago.
Category: Jeep
Expert:  Ron Z. replied 7 years ago.

This is a pretty straight forward code pointing to a fault in the Throttle Position Sensor. Replacing this sensor should solve the problem. The TPS is mounted to the throttle body.



  • Disconnect TPS electrical connector.graphic
  • Remove TPS mounting screws.

  • Remove TPS.



The throttle shaft end of throttle body slides into a socket in the TPS. The TPS must be installed so that it can be rotated a few degrees. (If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs). The TPS will be under slight tension when rotated.

  • Install TPS and retaining screws.
  • Tighten screws to 7 Nm (60 in. lbs.) torque.
  • Connect TPS electrical connector to TPS.
  • Manually operate throttle (by hand) to check for any TPS binding before starting engine.
Customer: replied 7 years ago.

We already replaced TPS oem parts.

Expert:  Ron Z. replied 7 years ago.

Ok. The next step is to check the wire harness from the TPS to the PCM for broken wires, or rubbed through wires grounding out. Also check all the fuses. If the wire harness and fuses look good, then unfortunately, the problem is going to be internal of the PCM. Also- make sure the installation was lined up correctly (see install procedure above). If the "tangs" are not lined correctly, this code will set.

Here is JEEP's official diagnostic of the P0123:


  • TPS voltage change not smooth
  • TPS harness/connectors intermittent problem (D)
  • TPS harness/connectors intermittent problem (C)
  • TPS harness/connectors observable problem
  • Throttle position sensor ground circuit open
  • TPS signal or S/C switch signal circuit shorted to voltage
  • Throttle position sensor signal circuit open
  • TPS signal circuit shorted to 5-volt supply circuit
  • TPS (voltage < 1.0 volt )
  • Powertrain control module
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