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Pinpoint Test Q: The Air Conditioning (A/C) Is Always On - A/C Mode Always Commanded On

WARNING: This page is about a different car, the 2014 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Before carrying out the following test, diagnose any HVAC or PCM DTCs.
  1. Q1 CHECK THE AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PCM PID WITH THE A/C OFF 
    • Enter the following diagnostic mode on the scan tool: PCM Data Logger.
    • Select PANEL press the A/C button (indicator off) on the HVAC controls and monitor the AC_REQ PCM PID.

    Does the AC_REQ PCM PID read NO? 

    • Yes  : GO to  Q6.
    • No  : GO to Q2  .
  2. Q2 CHECK THE AIR CONDITIONING SWITCH STATUS (CC_SW_AC) HVAC PID WITH THE A/C OFF 
    • Enter the following diagnostic mode on the scan tool: HVAC Data Logger.
    • Select PANEL on the HVAC controls and monitor the CC_SW_AC HVAC PID.

    Does the CC_SW_AC HVAC PID read Inactive? 

    • Yes  : GO to Q3  .
    • No  : GO to  Q5.
  3. Q3 CHECK THE AIR CONDITIONING SWITCH STATUS (CC_SW_AC) FCIM PID WITH THE A/C OFF 
    • Ignition ON.
    • Enter the following diagnostic mode on the scan tool: Front Controls Interface Module (FCIM) Data Logger.
    • Monitor the CC_SW_AC FCIM  PID
    • Select PANEL on the HVAC controls and monitor the CC_SW_AC FCIM  PID.

    Does the CC_SW_AC FCIM PID read Inactive? 

    • Yes  : GO to Q4  .
    • No  : INSTALL a new FCIM  . REFER to Refer to the appropriate article for the procedure. TEST the system for normal operation.
  4. Q4 CHECK THE AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PCM PID WITH HVAC MODULE DISCONNECTED 
    • Disconnect: HVAC Module - Base EMTC  C294A.
    • Disconnect: HVAC Module - Base EMTC  C294B.
    • Disconnect: HVAC Module - Remote Mount EMTC  C2357A.
    • Disconnect: HVAC Module - Remote Mount EMTC  C2357B.
    • Disconnect: HVAC Module - EATC  C228A.
    • Disconnect: HVAC Module - EATC  C228B.
    • Enter the following diagnostic mode on the scan tool: PCM Data Logger.
    • Monitor the AC_REQ PCM PID

    Does the AC_REQ PCM PID read NO? 

    • Yes  : GO to Q5  .
    • No  : GO to  Q6.
  5. Q5 CHECK FOR CORRECT HVAC MODULE OPERATION 
    • Ignition OFF.
    • Disconnect and inspect all HVAC module connectors.
    • 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
    • Connect all HVAC module connectors. Make sure they seat and latch correctly.
    • Ignition ON.
    • Clear the DTCs.
    • Enter the following diagnostic mode on the scan tool: Self-Test - HVAC Module.
    • Operate the system and verify the concern is still present.

    Is the concern still present? 

    • Yes  : CHECK OASIS  for any applicable TSBs  . If a TSB  exists for this concern, DISCONTINUE this test and FOLLOW TSB  instructions. If no TSB  addresses this concern, INSTALL a new HVAC module. REFER to HEATING VENTILATION AIR CONDITIONING (HVAC) 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.
  6. Q6 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect and inspect all PCM connectors.
    • 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
    • Connect all PCM connectors. Make sure they seat and latch correctly.
    • Clear the DTCs.
    • Enter the following diagnostic mode on the scan tool: Self-Test - PCM.
    • Operate the system and verify the concern is still present.

    Is the concern still present? 

    • Yes  : CHECK OASIS  for any applicable TSBs  . If a TSB  exists for this concern, DISCONTINUE this test and FOLLOW TSB  instructions. If no TSB  addresses this concern, INSTALL a new PCM. REFER to HEATING VENTILATION AIR CONDITIONING (HVAC) 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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