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Home >> Chrysler >> 2011 >> 300 C, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1656 (5.7L CNG - DTCS P000B To P0198 - 2500 Hd) >> DTC Troubleshooting >> P0073-Ambient Air Temperature Sensor Circuit High (Without DDM) >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FOR AN ACTIVE DTC 
    NOTE:

    Diagnose any CAN C Bus Communication DTCs before continuing.

    1. Turn the ignition one.
    2. With the scan tool, read DTCs.

      Is the DTC active or pending?

      Yes 

      • Go To  2

      No 

  2. CHECK THE (G31) AAT SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE 
    1. Turn the ignition off.
    2. Disconnect the Ambient Air Temperature Sensor (AAT) harness connector.
    3. Turn the ignition on, engine not running.
    4. Measure the voltage on the (G31) AAT Signal circuit in the AAT Sensor harness connector.

      Is the voltage above 5.2 volts?

      Yes 

      No 

      • Go To  3
  3. CHECK THE (G31) AAT SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Turn the ignition off.
    2. Disconnect the BCM harness connector.
    3. Measure the resistance of the (G31) AAT Signal circuit between the AAT Sensor harness connector and the BCM harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  4

      No 

      • Repair the (G31) AAT Signal circuit for an open or high resistance.
      • Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  4. CHECK THE (G931) SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE 
    1. Measure the resistance of the (G931) Sensor Ground circuit between the AAT Sensor harness connector to the BCM harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  5

      No 

      • Repair the (G931) Sensor Ground circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. CHECK THE ABILITY OF THE PCM TO READ THE AAT SENSOR SIGNAL 
    1. Reconnect the BCM harness connector.
    2. Turn the ignition on, engine not running.
    3. Connect a jumper between the (G31) AAT Signal circuit and the (G931) Sensor Ground circuit at the AAT Sensor harness connector.
    4. With a scan tool, read DTCs.
      NOTE:

      The scan tool should display the P0072-AMBIENT AIR TEMPERATURE SENSOR CIRCUIT LOW DTC as active or pending with the AAT Sensor harness connector unplugged.

      Does the scan tool display the DTC as described above?

      Yes 

      • Verify that there is good pin to terminal contact in the AAT Sensor and Body Control Module (BCM) connectors. If ok, replace the Ambient Air Temperature Sensor.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  6
  6. CHECK RELATED BCM AND COMPONENT CONNECTIONS 
    1. Disconnect all BCM harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. 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.

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

      Did the DTC return?

      Yes 

      No 

      • The wiring or poor connection problem has been repaired.
      • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .