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

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
NOTE: Before carrying out the following test, diagnose any HVAC control module or PCM DTCs.

  1. Q1 CHECK THE A/C CLUTCH RELAY

    Did the relay pass the component test? 

    Yes  GO to  Q2.
    No  INSTALL a new A/C clutch relay.

  2. Q2 CHECK THE A/C COMPRESSOR CLUTCH FIELD COIL VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE

    • Ignition OFF.
    • Disconnect: A/C compressor clutch field coil C100.
    • Disconnect: A/C clutch relay.
    • Ignition ON.
    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C100-1
      GFD134422Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is any voltage present? 

    Yes  REPAIR the circuit.
    No  GO to  Q3.

  3. Q3 COMPARE THE EVAPORATOR TEMPERATURE SENSOR RESISTANCE TO THE PCM AMBIENT AIR TEMPERATURE (AAT) PID

    • Ignition OFF.
    • Allow the vehicle exterior and interior to stabilize to the ambient temperature.
    • Disconnect: Evaporator temperature sensor C296.
    • Measure:
      Positive Lead Measurement / Action Negative Lead
      GFD136642Courtesy of FORD MOTOR COMPANY

      C296-1 component side
      GFD134423Courtesy of FORD MOTOR COMPANY
      GFD136642Courtesy of FORD MOTOR COMPANY

      C296-2 component side
    • Compare the evaporator temperature sensor measured resistance with the table below.
      Ambient Temperature Resistance (Ohms)
      -40 °C (-40 °F) 1, 005, 00-1, 104, 000
      -20 °C (-4 °F) 287, 811-307, 800
      0 °C (32 °F) 96, 890-101, 300
      20 °C (68 °F) 37, 080-38, 000
      25 °C (77 °F) 29, 700-30, 300
      30 °C (86 °F) 23, 840-24, 430
      35 °C (95 °F) 19, 260-19, 820
      40 °C (104 °F) 15, 660-16, 180
      60 °C (140 °F) 7, 239-7, 594
      100 °C (212 °F) 1, 943-2, 091
    • Ignition ON.
    • Using a diagnostic scan tool, monitor the PCM AAT PID.

    Are the temperature values similar? 

    Yes  GO to  Q4.
    No  GO to Pinpoint Test G .

  4. Q4 CHECK THE PCM (A/C) PRESSURE SENSOR (ACP_PRESS) PID

    • Using a diagnostic scan tool, monitor the PCM ACP_PRESS PID.
    • With the R-134a manifold gauge set connected, compare the pressure readings of the manifold gauge set and the ACP_PRESS PID.

    Are the pressure values of the manifold gauge set and the ACP_PRESS PID within ± 15 psi (103 KPA)? 

    Yes  GO to  Q5.
    No  GO to Pinpoint Test A .

  5. Q5 CHECK THE FCIM (A/C) SWITCH (CC_SW_AC) PID WITH THE A/C OFF

    • Start the engine.
    • Using a diagnostic scan tool, monitor the FCIM CC_SW_AC PID.
    • Select PANEL and press the A/C button (indicator off) on the HVAC controls.

    Does the PID display Inactive when the button is pressed and the indicator is off? 

    Yes  GO to  Q6.
    No  GO to  Q7.

  6. Q6 CHECK THE PCM AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PID WITH THE A/C OFF

    • Using a diagnostic scan tool, monitor the PCM AC_REQ PID.
    • Select PANEL and press the A/C button (indicator off) on the HVAC controls.

    Does the AC_REQ PID read No when the button is pressed and the indicator is off? 

    Yes  GO to  Q8.
    No  GO to  Q7.

  7. Q7 CHECK FOR CORRECT HVAC CONTROL MODULE OPERATION

    • Disconnect and inspect all HVAC control 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
    • Reconnect all HVAC control module 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 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 control module. REFER to Climate Control .
    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. Q8 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
    • Reconnect all PCM 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 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.
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