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Home >> Ford >> 2006 >> Focus ZX5 SE, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 989 (HVAC Control System - General Information And Diagnostics - (Except Hybrid)) >> Diagnostic Tests >> Climate Control System >> Pinpoint Tests >> Pinpoint Test J: The Air Conditioning (A/C) is Always On >> Pinpoint Test J: The Air Conditioning (A/C) Is Always On

Pinpoint Test J: The Air Conditioning (A/C) Is Always On

WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Before carrying out the following test, diagnose any PCM or instrument cluster DTCs.
NOTE: When disconnecting and reconnecting the pressure transducer electrical connector, make sure that the connector-locking device is in place and that the locking device and connector are correctly and fully seated.
  1. J1 CHECK THE AIR CONDITIONING SWITCH STATUS (AC_SEL_SW) HVAC (EMTC/EATC) PID WITH THE A/C OFF 
    • Key in ON position.
    • Enter the following diagnostic mode on the diagnostic tool: AC_SEL_SW HVAC PID
    • Select PANEL mode on the EMTC or EATC module and make sure the A/C button and indicator are OFF.
    • Does the AC_SEL_SW HVAC PID read not pressed? 
    1. YES  : Go to  J2.
    2. NO  : Go to  J7.
  2. J2 CHECK THE AIR CONDITIONING COMPRESSOR CYCLING SWITCH (ACCS) PCM PID WITH THE A/C OFF 
    • Enter the following diagnostic mode on the diagnostic tool: ACCS PCM PID
    • Select PANEL mode on the EMTC or EATC module and make sure the A/C button and indicator are OFF.
    • Does the ACCS PCM PID read OFF? 
    1. YES  : Go to  J3.
    2. NO  : Go to  J8.
  3. J3 CHECK THE AIR CONDITIONING CLUTCH (WAC/ACCR) PID WITH THE A/C OFF 
    • Enter the following diagnostic mode on the diagnostic tool: WAC/ACCR PCM PID
    • Select PANEL mode on the EMTC or EATC module and make sure the A/C button and indicator are OFF.
    • Does the WAC/ACCR PCM PID read OFF? 
    1. YES  : Go to  J4.
    2. NO  : Go to  J8.
  4. J4 CHECK THE AIR CONDITIONING CLUTCH ALLOWED (ACCLT_ALW) PID 
    • Key in OFF position.
    • Disconnect: Dual-Function Pressure Switch C1062
    • Key in ON position.
    • Enter the following diagnostic mode on the diagnostic tool: ACCLT_ALW PCM PID
    • Select MAX A/C on the EMTC module or press the PANEL and A/C manual override buttons (A/C indicator ON) on the EATC module.
    • Does the ACCLT_ALW PCM PID read YES? 
    1. YES  : REPAIR circuit CH421 (GY) for a short to voltage. TEST the system for normal operation.
    2. NO  : Go to  J5.
  5. J5 CHECK THE A/C COMPRESSOR OPERATION 
    • With the A/C low charge protection switch still disconnected, select MAX A/C on the EMTC module or press the PANEL and A/C manual override buttons (A/C indicator ON) on the EATC module.
    • Does the A/C compressor operate? 
    1. YES  : Go to  J6.
    2. NO  : INSTALL a new A/C low charge protection switch. REFER to CLIMATE CONTROL article. TEST the system for normal operation.
  6. J6 CHECK FOR VOLTAGE TO THE A/C COMPRESSOR CLUTCH FIELD COIL 
    • Key in OFF position.
    • Disconnect: A/C Compressor Clutch Field Coil C100
    • Key in ON position.
    • Select PANEL mode on the EMTC or EATC module and make sure the A/C button is OFF.
    • Measure the voltage between A/C compressor clutch field coil C100-1, circuit CH401 (VT/WH) , harness side and ground.
      • Fig 1: Measuring Voltage
      G04002936Courtesy of FORD MOTOR CO.
    • Is voltage present? 
    1. YES  : CARRY OUT the A/C clutch relay component test. Refer to appropriate COMPONENT TESTING article. CHECK the A/C clutch diode. INSTALL a new diode if necessary. If the relay tests OK, REPAIR circuit CH401 (VT/WH) for a short to voltage. TEST the system for normal operation.
    2. NO  : ADJUST the A/C compressor clutch gap. REFER to Air Conditioning (A/C) Clutch Air Gap Adjustment . TEST the system for normal operation.
  7. J7 CHECK THE MODULE CONNECTION 
    • Carry out the Electronic Automatic Temperature Control (EATC) Module and Electronic Manual Temperature Control (EMTC) Module Cold Boot Process.
      • NOTE: EATC systems only.
    • Carry out the EATC on-demand self test.
    • Operate the system.
    • Does the concern return? 
    1. YES  : INSTALL a new EATC or EMTC module. REFER to CLIMATE CONTROL article. 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. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
  8. J8 CHECK THE PCM MODULE CONNECTION 
    • Clear the DTCs.
    • Disconnect all of the PCM connectors.
    • Check for:
      • corrosion.
      • pushed-out connectors.
      • incorrectly seated connector.
    • Connect and correctly seat all of the PCM connectors.
    • Operate the system.
    • Does the concern return? 
    1. YES  : INSTALL a new PCM. 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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