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Home >> Ford >> 2009 >> Flex Limited, FWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Pinpoint Test DL: Cylinder Head Temperature (CHT) Sensor Through Pinpoint Test DY: Engine Oil Temperature (EOT) Sensor - (Except Diesel & Hybrid) >> Pinpoint Test DS: Air Conditioning Pressure (ACP) Transducer Sensor >> Test Procedure

Test Procedure

  1. DS1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 

    Are DTCs P0532, P0533, P1461, P1462, or P1463 present? 

    Yes No
    For DTC P0533, P1461, GO to  DS2.
    For DTC P0532, P1462, GO to  DS8.
    For DTC P1463, GO to  DS17.    		 For symptoms without DTCs, GO to  DS19.
    For all others, GO to DTC LIST .
  2. DS2 DTC P0533, P1461: CHECK THE ACP PID 
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the ACP_V PID.

    Is the voltage less than 4.9 V? 

    Yes No
    The ACP transducer sensor voltage is now below maximum. To determine if an intermittent condition exists,
    GO to  DS16.    		 GO to  DS3.
  3. DS3 CHECK THE VOLTAGE BETWEEN THE VREF AND SIGRTN CIRCUITS AT THE ACP TRANSDUCER SENSOR VEHICLE HARNESS CONNECTOR 
    • Air Conditioning Pressure (ACP) Transducer Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side
      VREF SIGRTN

    Is the voltage between 4 - 6 V? 

    Yes No
    GO to  DS4. GO to Pinpoint Test C .
  4. DS4 CHECK THE ACP CIRCUIT FOR A SHORT TO VREF 
    • Ignition OFF.
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side
      ACP VREF

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DS5. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  5. DS5 CHECK THE ACP CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-)
      ACP Ground

    Is the voltage less than 1 V? 

    Yes No
    GO to  DS6. REPAIR the short circuit to PWR. CLEAR the DTCs. REPEAT the self-test.
  6. DS6 CHECK FOR AN OPEN ACP CIRCUIT IN THE HARNESS 
    • Ignition OFF.
    • Measure the resistance between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-) PCM Connector, Harness Side
      ACP ACP

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DS7. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  7. DS7 CHECK THE PCM 
    • PCM connector connected.
    • Connect a 5 amp fused jumper wire between the following:
      Point A Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side Point B Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side
      ACP SIGRTN
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the ACP_V PID.

    Is the voltage less than 4.9 V? 

    Yes No
    INSTALL a new Air Conditioning Pressure (ACP) Transducer Sensor. CLEAR the DTCs. REPEAT the self-test. GO to  DS23.
  8. DS8 DTC P0532, P1462: CHECK THE ACP PID 
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the ACP_V PID.

    Is the voltage greater than 0.15 V? 

    Yes No
    The ACP transducer sensor voltage is now above the minimum. To determine if an intermittent condition exists,
    GO to  DS16.    		 GO to  DS9.
  9. DS9 CHECK THE VOLTAGE BETWEEN THE VREF AND SIGRTN CIRCUITS AT THE ACP TRANSDUCER SENSOR VEHICLE HARNESS CONNECTOR 
    • Air Conditioning Pressure (ACP) Transducer Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side
      VREF SIGRTN

    Is the voltage between 4 - 6 V? 

    Yes No
    GO to  DS10. GO to Pinpoint Test C .
  10. DS10 SIMULATE AN OPPOSITE SIGNAL TO THE PCM 
    • Ignition OFF.
    • Connect a 5 amp fused jumper wire between the following:
      Point A Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side Point B Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side
      VREF ACP
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the ACP_V PID.

    Is the voltage greater than 4 V? 

    Yes No
    INSTALL a new Air Conditioning Pressure (ACP) Transducer Sensor. CLEAR the DTCs. REPEAT the self-test. GO to  DS11.
  11. DS11 CHECK THE ACP CIRCUIT FOR A SHORT TO GND 
    • Ignition OFF.
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-)
      ACP Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DS12. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  12. DS12 CHECK THE ACP CIRCUIT FOR A SHORT TO SIGRTN 
    • Measure the resistance between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side
      ACP SIGRTN

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  DS13. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  13. DS13 CHECK THE ACP CIRCUIT(S) FOR AN OPEN IN THE HARNESS 
    • Measure the resistance between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-) PCM Connector, Harness Side
      ACP ACP

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  DS14. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  14. DS14 CHECK FOR THE A/C CLUTCH TO ENGAGE 
    • PCM connector connected.
    • Air Conditioning Pressure (ACP) Transducer Sensor connector connected.
    • Ignition ON, engine running.
    • While listening for the A/C clutch to engage, turn the A/C on. Repeat if necessary.

    Does the A/C engage when the A/C is turned on? 

    Yes No
    GO to  DS23. GO to  DS15.
  15. DS15 VERIFY THE A/C SYSTEM FUNCTION, INCLUDING THE REFRIGERANT CHARGE 
    • Restore the vehicle.
    • Verify the A/C system function, including the refrigerant charge. Refer to the appropriate Climate Control System article .

    Does the A/C system have the correct refrigerant charge and if so does the A/C system function correctly? 

    Yes No
    GO to  DS23. REFER to the appropriate Climate Control System article , and DIAGNOSE the A/C is inoperative/does not operate correctly symptom.
  16. DS16 CHECK THE ACP CIRCUIT FOR AN INTERMITTENT CONCERN 
    NOTE: A concern is indicated by a sudden change in voltage.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the ACP_V PID.
    • Observe the ACP for an indication of a concern while carrying out the following:
      • Shake, wiggle, and bend the ACP, SIGRTN, and VREF wires between the ACP sensor and PCM
      • Lightly tap on the ACP transducer sensor to simulate road shock

    Is a concern present? 

    Yes No
    ISOLATE the concern and REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. Unable to duplicate or identify the concern at this time.
    GO to Pinpoint Test Z .
  17. DS17 DTC P1463: VERIFY THE A/C CLUTCH CAN DISENGAGE 
    • Turn the A/C and defroster OFF.
    • Ignition ON, engine running.
    • Verify the A/C clutch can disengage.

    Is the A/C clutch disengaged? 

    Yes No
    GO to  DS18. REFER to the appropriate Climate Control System article , and DIAGNOSE the A/C is always on symptom.
  18. DS18 CHECK FOR VOLTAGE AND GROUND TO THE A/C CLUTCH USING A NONPOWERED TEST LAMP 
    NOTE: If voltage and ground to the A/C clutch have already been checked or the A/C clutch can be heard clicking on when the A/C is turned on, go to the question at the end of this test step.
    • Ignition OFF.
    • A/CCS Switch connector disconnected.
    • Connect a jumper wire in the A/C low pressure cycling switch harness connector to complete the circuit.
    • A/CC Assembly connector disconnected.
    • Connect a non-powered test lamp between the voltage pin and ground pin at the A/C clutch harness connector.
    • Ignition ON, engine running.
    • Turn the A/C on, and wait 15 seconds.
    • Monitor the test lamp.
    • Connect the A/C clutch and A/C cycling switch when done testing.

    Does the lamp illuminate, or can the A/C clutch be heard clicking on? 

    Yes No
    GO to  DS19. REFER to the appropriate Climate Control System article , and DIAGNOSE the A/C is inoperative/does not operate correctly symptom.
  19. DS19 DETERMINE IF A SUFFICIENT A/C PRESSURE CHANGE CAN BE DETECTED BY THE ACP PID 
    • Ignition ON, engine running.
    • Turn the A/C and defroster OFF.
    • Access the PCM and monitor the ACP_V PID.
    • Turn the A/C and defroster OFF.
    • Five seconds after A/C clutch engagement, note the voltage. If the clutch does not engage, follow the NO answer instructions.

    Does the ACP PID change more than 0.3 volt within 5 seconds of clutch engagement? 

    Yes No
    The ACP transducer sensor and the PCM can detect a sufficient change in the A/C pressure.
    For symptom without DTC P1463, REFER to SYMPTOM CHARTS - GASOLINE MODELS .
    For all others, REFER to the appropriate Climate Control System article , and DIAGNOSE the A/C is inoperative/does not operate correctly symptom.    		 GO to  DS20.
  20. DS20 CHECK THE A/C SYSTEM PRESSURE AND PRESSURE CHANGE 
    • Ignition OFF.
    • Install an A/C system manifold gauge set and check the A/C system high pressure reading.
    • Turn the A/C and defroster OFF.
    • Ignition ON, engine running.
    • Note the A/C high pressure reading.
    • While monitoring the A/C system high pressure reading, turn the A/C on. Five seconds after clutch engagement, note the pressure (the pressure should increase).
    • A/C and defroster OFF.

    Does the A/C high pressure reading change more than 207 kPa (30 psi) within 5 seconds of clutch engagement? 

    Yes No
    GO to  DS21. REFER to the appropriate Climate Control System article , and DIAGNOSE the A/C is inoperative/does not operate correctly symptom.
  21. DS21 CHECK THE VOLTAGE BETWEEN THE VREF AND SIGRTN CIRCUITS AT THE ACP TRANSDUCER SENSOR VEHICLE HARNESS CONNECTOR 
    • Ignition OFF.
    • Air Conditioning Pressure (ACP) Transducer Sensor connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side
      VREF SIGRTN

    Is the voltage between 4 - 6 V? 

    Yes No
    GO to  DS22. GO to Pinpoint Test C .
  22. DS22 CHECK THE ACP CIRCUIT(S) FOR AN OPEN IN THE HARNESS 
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) Air Conditioning Pressure (ACP) Transducer Sensor Connector, Harness Side (-) PCM Connector, Harness Side
      ACP ACP

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new Air Conditioning Pressure (ACP) Transducer Sensor. CLEAR the DTCs. REPEAT the self-test. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  23. DS23 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the PCM self-test and verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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