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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-77-Front Left Temperature Door 1 Control-Commanded Position Not Reachable >> 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 HVAC Actuator Calibration Test and recheck DTCs.

    Did the DTC return?

    Yes 

    • Go To  3

    No 

  3. INSPECT THE DOOR, DUCTS, AND LINKAGE FOR CONDITIONS THAT COULD CAUSE BINDING 
    1. Inspect the door and linkage for conditions that could cause the door to not move freely across the total travel of the door.
    2. Check for debris or objects in the ducts that could hinder the door movement.
    3. Inspect the door stops for damage.
    4. If necessary to gain access to the applicable door and ducts. Refer to HOUSING, HVAC, REMOVAL AND INSTALLATION .

      Were any problems found?

      Yes 

      • Repair the binding condition as necessary.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .

      No 

      • Go To  4
  4. REPLACE THE FRONT LEFT TEMPERATURE MODE DOOR ACTUATOR AND CHECK FOR THE DTC TO RETURN 
    1. Replace the Front Left Temperature Door Actuator in accordance with the Service Information. Refer to ACTUATOR, BLEND DOOR, FRONT, REMOVAL AND INSTALLATION .
    2. Connect the Front/Left Temperature Mode Door Actuator, HVAC, and any other disconnected harness connectors.
    3. Turn the ignition on.
    4. With the scan tool, erase DTCs.
    5. Using the Environmental Data and When Monitored conditions, operate the vehicle within the conditions that set the DTC.
    6. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go To  5

      No 

      • Replacing the Front Left Temperature Mode Door Actuator corrected the condition.
      • Perform the HVAC VERIFICATION TEST. Refer to HVAC VERIFICATION TEST .
  5. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all HVAC Module 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.
      • Perform a terminal drag test on each connector terminal to verify proper terminal tension.

      Repair any conditions that are found.

    5. Reconnect all HVAC Module 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. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    10. With the scan tool, read HVAC Module DTCs.

      Did the DTC return?

      Yes 

      No 

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