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Home >> Jeep >> 2024 >> Gladiator Nighthawk, Part Time T/Case Control, Automatic Trans >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> 3.6L (GPEC 2A) - DTCS P2118 To P2172 >> DTC Troubleshooting >> P2127-Accelerator Pedal Position Sensor 2 Circuit Low >> Diagnostic Test
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Diagnostic Test

  1. READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN 
    1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
    2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
    3. With the scan tool, erase all DTCs.
    4. Turn the ignition off for a minimum of 10.0 seconds.
    5. Turn the ignition on.
    6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
    7. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go To  2

      No 

  2. CHECK FOR OTHER DTCS 
    1. Refer to the recorded DTCs.

      Are there any 5-Volt Sensor DTCs active or pending?

      Yes 

      No 

      • Go To  3
  3. CHECK THE APP SENSOR HARNESS CONNECTOR AND TERMINALS 
    1. Turn the ignition off.
    2. Check the APP Sensor harness connector for proper connection at the APP Sensor.
    3. Verify that the connector is completely plugged in and locked prior to disconnecting.
    4. Disconnect the APP Sensor harness connector and check for pushed out or spread terminals, brineling on terminals, discoloration from excessive heat, or corrosion and water intrusion.

      Were any issues found with the connector or terminals?

      Yes 

      • Repair the found issues in accordance with the service information or properly connect and lock the APP Sensor harness connector.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK THE (K854) 5-VOLT SUPPLY CIRCUIT FOR PROPER VOLTAGE AT THE APP SENSOR HARNESS CONNECTOR 
    1. Turn the ignition off.
    2. Disconnect the harness connector at the component of the circuit being tested. Note:  The ECU harness connector should still be connected during this test step.
    3. Turn the ignition on.
    4. Set the DVOM to measure DC voltage.
    5. Connect the negative lead of the DVOM to a known good ground.
    6. With the positive lead of the DVOM, measure the voltage of the circuit being tested at the component harness connector.
    7. If it is necessary to probe a terminal at a PCM harness connector, connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
      NOTE:

      Normal operating voltage should be between 4.8 and 5.2 volts.

      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 the GPEC Diagnostic Adaptor to perform the diagnosis.

      Does the circuit have the proper voltage present?

      Yes 

      • Go To  5

      No 

      • Repair the (K854) 5-Volt Supply circuit for an open circuit or short to ground.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. ISOLATE AND CHECK THE APP SENSOR (K29) POSITION SIGNAL 2 CIRCUIT FOR A SHORT TO GROUND 
    1. The ignition must be off when checking a circuit for continuity to ground.
    2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
    3. Connect the negative lead of the DVOM to a known good ground.
    4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
    5. If it is necessary to probe a terminal at a PCM harness connector, connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
      NOTE:

      There should be no continuity between ground and the circuit being tested.

      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 the GPEC Diagnostic Adaptor to perform the diagnosis.

      Is there continuity between ground and the circuit being tested?

      Yes 

      • Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  6
  6. ISOLATE AND CHECK THE APP SENSOR (K29) POSITION SIGNAL 2 CIRCUIT FOR A SHORT TO THE (K400) SENSOR GROUND 2 CIRCUIT 
    1. The ignition must be off when checking for a short between circuits.
    2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
    3. Connect the test leads of the DVOM and check for continuity between the circuits being tested at the component harness connector.
    4. If it is necessary to probe a terminal at a PCM harness connector, connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
      NOTE:

      There should be no continuity between the circuits being tested.

      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 the GPEC Diagnostic Adaptor to perform the diagnosis.

      Is there continuity between the circuits?

      Yes 

      No 

      • Go To  7
  7. ISOLATE AND CHECK THE APP SENSOR (K29) POSITION SIGNAL 2 CIRCUIT FOR A SHORT TO THE (K167) SENSOR GROUND 1 CIRCUIT 
    1. The ignition must be off when checking for a short between circuits.
    2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
    3. Connect the test leads of the DVOM and check for continuity between the circuits being tested at the component harness connector.
    4. If it is necessary to probe a terminal at a PCM harness connector, connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
      NOTE:

      There should be no continuity between the circuits being tested.

      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 the GPEC Diagnostic Adaptor to perform the diagnosis.

      Is there continuity between the circuits?

      Yes 

      No 

      • Go To  8
  8. ISOLATE AND CHECK THE APP SENSOR (K29) POSITION SIGNAL 2 CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. The ignition must be off when checking the continuity of a circuit.
    2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
    3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note:  The meter leads can add resistance to the measurement value.
    4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
    5. Connect the other lead to the circuit being tested at the GPEC Adaptor and measure the resistance of the circuit.
    6. If it is necessary to probe a terminal at a PCM harness connector, connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
      NOTE:

      The GPEC Diagnostic Adaptor can add up to 1.5 Ohms of resistance to the circuit.

      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 the GPEC Diagnostic Adaptor to perform the diagnosis.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  9

      No 

  9. ISOLATE AND CHECK THE (K400) SENSOR GROUND 2 CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. The ignition must be off when checking the continuity of a circuit.
    2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the component harness connector containing the circuit being tested. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
    3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note:  The meter leads can add resistance to the measurement value.
    4. Connect one lead of the DVOM to the circuit being tested at the component harness connector.
    5. Connect the other lead to the circuit being tested at the GPEC Adaptor and measure the resistance of the circuit.
    6. If it is necessary to probe a terminal at a PCM harness connector, connect the (special tool #10436, Adapter, GPEC Diagnostic) to the appropriate PCM harness connector.
      NOTE:

      The GPEC Diagnostic Adaptor can add up to 1.5 Ohms of resistance to the circuit.

      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 the GPEC Diagnostic Adaptor to perform the diagnosis.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  10

      No 

  10. CHECK RELATED PCM AND APP SENSOR CONNECTIONS 
    1. Disconnect all related in-line harness connections (if equipped).
    2. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions: Repair any conditions that are found.
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Brineling on terminals of sensor or harness connector.
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Check for spread terminals and verify proper terminal tension.
      NOTE:

      Before reconnecting the harness connectors, clean the terminals with Mopar electrical connector cleaner and apply a light application of dielectric grease to the face of the connector with your finger. This will aid in preventing any future issues with the sensor terminals and connector pins; excessive amounts of dielectric grease can cause damage to the sensor terminals, connector pins, and weather seals.

    3. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    4. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    5. Reconnect the APP Sensor harness connector. Be certain that the connectors is fully seated and the connector locks are fully engaged.
    6. With the scan tool, erase DTCs.
    7. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    8. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go To  11

      No 

      • The wiring or poor connection problem has been repaired.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  11. CONNECT A FUSED JUMPER BETWEEN THE APP SENSOR (K29) POSITION SIGNAL 2 CIRCUIT AND THE (K854) 5-VOLT SUPPLY CIRCUIT AT THE APP SENSOR HARNESS CONNECTOR - VERIFY ABILITY OF THE PCM TO DETECT THE SENSOR SIGNAL 
    1. The Electronic Control Module (ECU) harness connectors must be connected to the ECU during this test step.
    2. Disconnect the sensor harness connector.
    3. With the ignition in the off position, connect a fused jumper between the sensor signal circuit and the 5-Volt Supply circuit at the sensor harness connector.
    4. Turn the ignition on.
    5. With the scan tool, read APP Sensor data.

      Does the scan tool display approximately 5 volts?

      Yes 

      • Replace the APP Sensor in accordance with the Service Information. After installation is complete, perform the ETC RELEARN function.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

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