LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 2009 >> Commander Overland, 4WD >> Repair and Diagnosis >> Engine Performance >> System >> DTCS P000B To P0123 - NGC >> P0123-Throttle Position Sensor 1 Circuit High >> Diagnostic Test
September 30: LEMON manuals is back up on a temporary server! Slowness is possible

Diagnostic Test

  1. ACTIVE DTC 
    NOTE: When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode.
    NOTE: Make sure the throttle is fully closed and free from binding or carbon build up.
    NOTE: If a 5-Volt Supply DTC has also set, diagnose the 5-Volt DTC before continuing.
    NOTE: If P2101 is also set, then make sure that the blade moves freely and does not hang up near Wide Open Throttle before trying to repair P0123.
    1. Start the engine and allow it to reach operating temperature.
    2. With the scan tool select View DTCs.
      NOTE: If the DTC does not reset it may be necessary to test drive the vehicle.
      NOTE: If the P2123-APP Sensor 1 Circuit High DTC is also Active, diagnose the P2123 before continuing with the P0123 diagnostic procedure.

      Is the DTC Active at this time?

      Yes 

      • Go to step  2

      No 

      • Go to step  8
  2. THROTTLE POSITION SENSOR 
    Fig 1: Throttle Body Harness Connector
    GC0090679Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the Throttle Body harness connector.
    3. Ignition on, engine not running.
    4. With a scan tool, monitor the TP Sensor No. 1 voltage.
    5. Connect a jumper wire between the (K22) TP Sensor No. 1 Signal circuit and the (K922) TP Sensor Return circuit in the Throttle Body harness connector.
      NOTE: The sensor voltage should be approximately 0.0 volts (plus or minus.1 volt) with the jumper wire in place.

      Does the scan tool display the voltage as described above?

      Yes 

      • Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, replace the Throttle Body Assembly. Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, using a scan tool select the ETC RELEARN function.
      • Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .

      No 

      • Go to step  3
        NOTE: Remove the jumper wire before continuing.
  3. (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO VOLTAGE 
    Fig 2: Checking TP Sensor Signal Circuit
    GC0090680Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the C2 PCM harness connector.
    3. Ignition on, engine not running.
    4. Measure the voltage on the (K22) TP Sensor No. 1 Signal circuit in the Throttle Body harness connector.

      Is there any voltage present?

      Yes 

      No 

      • Go to step  4
  4. (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT OPEN 
    Fig 3: Checking TP Sensor Signal Circuit
    GC0090676Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
      CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install PCM Pinout Box 8815 to perform diagnosis.
    2. Measure the resistance of the (K22) TP Sensor No. 1 Signal circuit from the Throttle Body harness connector to the appropriate terminal of special tool #8815.

      Is the resistance below 5.0 ohms?

      Yes 

      • Go to step  5

      No 

  5. (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT 
    Fig 4: Checking TP Sensor Signal Circuit
    GC0090681Courtesy of CHRYSLER LLC
    1. Measure the resistance between the (K22) TP Sensor No. 1 Signal circuit and the (F855) 5-volt Supply circuit in the Throttle Body harness connector.

      Is the resistance below 100 ohms?

      Yes 

      No 

      • Go to step  6
  6. (K922) TP SENSOR RETURN CIRCUIT OPEN 
    Fig 5: Checking TP Sensor Return Circuit
    GC0090682Courtesy of CHRYSLER LLC
    1. Measure the resistance of the (K922) TP Sensor Return circuit from the Throttle Body harness connector to the appropriate terminal of special tool #8815.

      Is the resistance below 5.0 ohms?

      Yes 

      • Go to step  7

      No 

  7. POWERTRAIN CONTROL MODULE (PCM) 
    1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM).
    2. Look for any chafed, pierced, pinched, or partially broken wires.
    3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors.
    4. Refer to any Technical Service Bulletins that may apply.

      Were there any problems found?

      Yes 

      No 

  8. THROTTLE FOLLOWER TEST 
    1. With a scan tool, perform the ETC Throttle Follower Test.
    2. Monitor the TP Sensor No. 1 voltage.

      Does the voltage start at approximately 0.7 of a volt and increase to approximately 4.3 volts with a smooth transition?

      Yes 

      No 

      • Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If OK, replace the Throttle Body Assembly. Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, using a scan tool select the ETC RELEARN function.
      • Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
scientia non olet · About LEMON Manuals