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 2013 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.

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 DataLogger.
- 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.
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 DataLogger.
- 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.
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) DataLogger.
- 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 the INFORMATION SYSTEM AND ENTERTAINMENT SYSTEM - AM/FM , INFORMATION SYSTEM AND ENTERTAINMENT SYSTEM - AM/FM/CD , INFORMATION SYSTEM AND ENTERTAINMENT SYSTEM - SONY 8 INCH TOUCHSCREEN , INFORMATION SYSTEM AND ENTERTAINMENT SYSTEM - 4.2INCH DISPLAY , or INFORMATION SYSTEM AND ENTERTAINMENT SYSTEM - 8 INCH TOUCHSCREEN removal and installation for the procedure. TEST the system for normal operation.
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 DataLogger.
- Monitor the AC_REQ PCM PID
- Does the AC_REQ PCM PID read NO?
- Yes : GO to Q5.
- No : GO to Q6.
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 HVAC - CLIMATE CONTROL SYSTEM (SERVICE INFORMATION) .
- 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.
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 ELECTRONIC ENGINE CONTROLS .
- 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.