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Home >> Jeep >> 2021 >> Grand Cherokee L Laredo, RWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Heating & Air Conditioning (ATC) - DTCS B11CB-15 To B1E9B-92 >> DTC Troubleshooting >> B11CB-4B-Front Left Temperature Door 1 Control-Over Temperature >> Diagnostic Test

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 Heating Ventilation Air Conditioning Module (HVAC) 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. PERFORM THE APPROPRIATE HVAC ACTUATOR CALIBRATION / AUTO ADDRESSING ROUTINE TEST AND CHECK FOR THE DTC TO RETURN 
    NOTE:

    NO HVAC mode or temp functions will perform as desired unless auto-addressing was successful. 

    NOTE:

    NO Heated/Vented Seats functions will operate unless auto-addressing was successful. 

    NOTE:

    Auto-addressing needs to be done every time a CSM/CSWSM/CRSM or an Actuator is replaced. 

    NOTE:

    Diagnose and repair all LIN Bus related DTC's before performing this test procedure. 

    With the scan tool, perform the appropriate HVAC Actuator Calibration/Auto Addressing Routine and recheck DTCs.

    Did any of the above test routines fail?

    Yes 

    • Replace the faulty component that failed the HVAC Actuator Calibration/Auto Addressing Routine and or LIN issue in Accordance with the Service Information.
    • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .

    No 

  3. CHECK FOR A SHORTED CONTROL HEAD 
    1. Disconnect the power supply from the control head for a minimum of 2 seconds and reconnect.

      Operate the HVAC as designed. Is the customer complaint still present??

      Yes 

      • Go To  6

      No 

  4. ISOLATE AND CHECK THE (C211) ACTUATOR FEED 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 Heating Ventilation Air Conditioning Module (HVAC) 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.
      NOTE:

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

    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 HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .

    No 

    • Go To  5
  5. ISOLATE AND CHECK THE (C211) ACTUATOR FEED CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT AT THE FRONT LEFT TEMPERATURE DOOR 1 ACTUATOR HARNESS CONNECTOR 
    1. The ignition must be off when performing a resistance check to find a short between circuits.
    2. Isolate the circuit by disconnecting the Heating Ventilation Air Conditioning Module (HVAC) and every component harness connector containing the circuit being tested. At this time leave all in-line connectors connected. Note:  Use the wiring diagram as a guide to follow the path of the circuit.
    3. Connect one lead of the DVOM to the circuit being tested at the HVAC harness connector.
    4. With the other lead of the DVOM probe all other circuits at the HVAC harness connector.
    NOTE:

    With the circuit isolated there should be no continuity between the circuit being tested and any other circuit.

    Is there continuity between the circuit being tested and any other circuit?

    Yes 

    • Repair the short between the circuits that have continuity. Use the wiring diagram as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
    • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .

    No 

    • Go To  6
  6. REPLACE THE FRONT LEFT TEMPERATURE DOOR 1 ACTUATOR AND RETEST FOR DTCS 
    1. Turn the ignition off.
    2. Replace the component in accordance with the Service Information.
    3. Connect the component and Heating Ventilation Air Conditioning Module (HVAC) harness connectors.
    4. Turn the ignition on.
    5. With the scan tool, erase all DTCs.
    6. Turn the ignition off for a minimum of 10.0 seconds.
    7. Turn the ignition on.
    8. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
    9. With the scan tool, read DTCs.

    Did the DTC return?

    Yes 

    • Go To  7

    No 

    • Replacing the faulty component repaired the fault.
    • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  7. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all HVAC 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. Connect all HVAC harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    7. Connect 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 

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