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Pinpoint Test Aa : U0253:00

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  1. Automatic Climate Control System for schematic and connector information.

    Normal Operation and Fault Conditions 

    The HVAC. Uses information contained in messages from the APIM sent on the HS-CAN3 for 5 seconds.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    HVAC U0253:00 Lost Communication With Accessory Protocol Interface Module: No Sub Type Information This DTC sets in the HVAC module if data messages received from the APIM are missing for 6 seconds.

    Possible Sources 

    • Vehicle communication bus
    • APIM
    • HVAC control module

  2. AA1 CHECK THE COMMUNICATION NETWORK

    • Ignition ON.

    • Using a diagnostic scan tool, perform network test.

    Does the APIM pass the network test? 

    Yes  GO to  AA2
    No 

  3. AA2 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE APIM (SYNC MODULE) SELF-TEST

    • Using a diagnostic scan tool, perform APIM self-test.

    • Check for Diagnostic Trouble Codes (DTCs) from the APIM self-test.

    Is DTC U3003:16 or DTC U3003:17 recorded? 

    Yes  DIAGNOSE the battery voltage Diagnostic Trouble Codes (DTCs). Refer to AUDIO SYSTEM for the procedure.
    No  GO to  AA3

  4. AA3 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE HEATING, VENTILATION, AND AIR CONDITIONING (HVAC) CONTROL MODULE SELF-TEST

    • Check for recorded Diagnostic Trouble Codes (DTCs) from the HVAC module self-test.

    Is DTC U3003:16 or DTC U3003:17 recorded? 

    Yes  GO to Pinpoint Test V 
    No  GO to  AA4

  5. AA4 RECHECK THE HEATING, VENTILATION, AND AIR CONDITIONING (HVAC) MODULE DIAGNOSTIC TROUBLE CODES (DTCS)

    • Clear all Diagnostic Trouble Codes (DTCs).

    • Ignition OFF.

    • Ignition ON.

    • Repeat the HVAC control module self-test.

    Is DTC U0253:00 retrieved again? 

    Yes  GO to  AA5
    No  The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.

  6. AA5 CHECK FOR DIAGNOSTIC TROUBLE CODE (DTC) U0253:00 SET IN OTHER MODULES

    • Using a diagnostic scan tool, clear all Diagnostic Trouble Codes (DTCs).

    • Ignition OFF.

    • Wait 10 seconds.

    • Ignition ON.

    • Using a diagnostic scan tool, retrieve all Continuous Memory Diagnostic Trouble Codes (CMDTCs).

    Is DTC U0253:00 set in any other modules? 

    Yes  GO to  AA6
    No  GO to  AA7

  7. AA6 CHECK FOR CORRECT APIM (SYNC MODULE) OPERATION

    • Ignition OFF.

    • Disconnect and inspect the APIM connector.

    • Repair:

      • corrosion (install new connector or terminals - clean module pins)
      • damaged or bent pins - install new terminals/pins
      • pushed-out pins - install new pins as necessary

    • Reconnect the APIM connector. Make sure it seats and latches correctly.

    • Operate the system and determine if the concern is still present.

    Is the concern still present? 

    Yes  CHECK On-Line Automotive Service Information System (OASIS) for any applicable Technical Service Bulletins (TSBs). If a Technical Service Bulletin (TSB) exists for this concern, DISCONTINUE this test and FOLLOW Technical Service Bulletin (TSB) instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new APIM. Refer to AUDIO SYSTEM for the procedure.
    No  The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.

  8. AA7 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE OPERATION

    • Ignition OFF.

    • Disconnect and inspect all HVAC control module electrical connectors (if not previously disconnected).

    • Repair:

      • corrosion (install new connector or terminal - clean module pins)
      • damaged or bent pins - install new terminals or pins
      • pushed-out pins - install new pins as necessary

    • Connect all HVAC control module electrical connectors. Make sure they seat and latch correctly.

    • Operate the system and determine if the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new HVAC control module. REFER to: Heating, Ventilation and Air Conditioning (HVAC) Control Module .
    No  The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
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