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

  1. N1 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) DataLogger.
    • Monitor the CC_SW_AC FCIM PID
    • Select PANEL press the A/C button (indicator off) on the HVAC controls.
    • Does the CC_SW_AC HVAC PID read Inactive? 
      1. YES  : GO to N2.
      2. No  : INSTALL a new Front Controls Interface Module (FCIM). REFER to INFORMATION AND ENTERTAINMENT SYSTEMS . TEST the system for normal operation.
  2. N2 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 DataLogger.
    • Select PANEL press the A/C button (indicator off) on the HVAC controls.
    • Monitor the AC_REQ PCM PID
    • Does the AC_REQ PCM PID read OFF? 
      1. YES  : GO to  N5.
      2. No  : GO to N3.
  3. N3 CHECK THE AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PCM PID WITH HVAC MODULE DISCONNECTED 
    • Disconnect: HVAC Module - Electronic Manual Temperature Control (EMTC) C2357.
    • Disconnect: HVAC Module - Dual Automatic Temperature Control (DATC) C228A.
    • Enter the following diagnostic mode on the scan tool: PCM DataLogger.
    • Monitor the AC_REQ PCM PID
    • Does the AC_REQ PCM PID read OFF? 
      1. YES  : GO to N4.
      2. No  : GO to  N5.
  4. N4 CHECK THE HVAC MODULE CONNECTION 
    • Inspect the HVAC module component and harness side connectors for:
      • Corrosion
      • Damaged pins
      • Pushed-out terminals
    • Connect and correctly seat all the HVAC module connectors.
    • 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? 
      1. YES  : INSTALL a new HVAC module. REFER to CLIMATE CONTROL . TEST the system for normal operation.
      2. No  : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.
  5. N5 CHECK THE PCM CONNECTION 
    • Disconnect all the PCM connectors.
    • Inspect the PCM component and harness side connectors for:
      • Corrosion
      • Damaged pins
      • Pushed-out terminals
    • Connect and correctly seat all the PCM connectors.
    • 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? 
      1. YES  : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS . TEST the system for normal operation.
      2. No  : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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