LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 2021 >> Grand Cherokee Trackhawk >> Repair and Diagnosis >> Engine Performance >> System >> 6.2L - DTCS C053D To P0141 >> DTC Troubleshooting >> P0111-Intake Air Temperature Sensor 1 Performance >> Diagnostic Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Test

  1. CHECK FOR AN ACTIVE CONDITION 
    1. Turn the ignition off.
    2. Allow the vehicle to sit with the ignition off in an environment where the temperature is consistent and above -7°C (19.4°F) until the engine coolant temperature is equal to ambient temperature.
    3. Turn the ignition on.
    4. With a scan tool, compare the IAT Sensor value with the other temperature sensor signals.

      Is the IAT Sensor value within 15°C (59°F) of the other sensor values?

      Yes 

      No 

      • Go To  2
  2. CHECK FOR HIGH RESISTANCE IN THE IAT SENSOR (K21) TEMP SIGNAL CIRCUIT 
    1. Turn the ignition off.
    2. Disconnect the IAT Sensor harness connector.
    3. Disconnect the PCM C2 harness connector.
      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.

    4. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
    5. Measure the resistance of the IAT Sensor (K21) Temp Signal circuit between the IAT Sensor harness connector and the GPEC Adaptor.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  3

      No 

      • Repair the IAT Sensor (K21) Temp Signal circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  3. CHECK FOR high RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT 
    1. Measure the resistance of the (K900) Sensor Ground circuit between the IAT Sensor harness connector and the GPEC Adaptor.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  4

      No 

      • Repair the (K900) Sensor Ground for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  4. CHECK THE ABILITY OF THE PCM TO READ THE IAT SENSOR TEMP SIGNAL 
    1. Turn the ignition off.
    2. Connect the PCM C2 harness connector.
    3. Turn the ignition on.
    4. With the scan tool, read the IAT Sensor signal voltage with the connector unplugged.
    5. Connect a jumper between the (K900) Sensor Ground circuit and the IAT Sensor (K21) Temp Signal circuit at the IAT Sensor harness connector.
    6. With the scan tool, read the IAT Sensor signal voltage with the jumper in place.
      NOTE:

      The voltage should read 5.0 volts with the connector unplugged and below 0.1 volts with the jumper in place.

      Does the voltage read as described above?

      Yes 

      • Replace the IAT Sensor in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  5
  5. CHECK RELATED PCM AND COMPONENT CONNECTIONS 
    1. Perform any Service Bulletins that apply.
    2. Disconnect all PCM harness connectors.
    3. Disconnect all related in-line harness connections (if equipped).
    4. Disconnect the related component harness connectors.
    5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • 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.

      Repair any conditions that are found.

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

      Did the DTC return?

      Yes 

      No 

      • The wiring or poor connection problem has been repaired.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
scientia non olet · About LEMON Manuals