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Home >> Ford >> 2012 >> Explorer Limited, 3.5 8, AWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Auxiliary Climate Control >> Diagnostic Routine(S) >> Diagnostic Routine A >> Pinpoint Test

Pinpoint Test

  1. CHECK THE HVAC MODULE FOR DTCs 
    1. Ignition ON.
    2. Using a scan tool, perform a HVAC module self-test.

      Are any DTCs present? 

      • Yes  For DTC B10B0:12, GO to 2  .

        For DTC B10B0:13, GO to 4  .

        For DTC B10BA:14, GO to 7  .

      • No  : GO to 7  .
  2. CHECK THE AUXILIARY BLOWER MOTOR RELAY FUNCTIONALITY
    1. Install a known good auxiliary blower motor relay.

      Does the auxiliary blower motor function correctly? 

      • Yes:  INSTALL a new auxiliary blower motor relay.
      • No  : GO to 3  .
  3. CHECK THE AUXILIARY BLOWER MOTOR CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
    1. Ignition OFF.
    2. Disconnect: Auxiliary Blower Motor Relay.
    3. Disconnect: HVAC module C228B.
    4. Ignition ON.
    5. Measure:
      BJB Ground
      G08033818
      G08031601
      Auxiliary Blower Motor Relay Socket Ground
      Pin Circuit Measurement / Action Pin Circuit
      2 CH112 (VT/WH)
      G08033411
      		 - Ground

      Is any voltage present? 

      • Yes:  REPAIR the circuit.
      • No  : GO to 16  .
  4. CHECK THE AUXILIARY BLOWER MOTOR RELAY FUNCTIONALITY
    1. Install a known good auxiliary blower motor relay.

      Does the auxiliary blower motor function correctly? 

      • Yes:  INSTALL a new auxiliary blower motor relay.
      • No  : GO to 5  .
  5. CHECK THE AUXILIARY BLOWER MOTOR RELAY COIL SUPPLY VOLTAGE
    1. Ignition OFF.
    2. Disconnect: Auxiliary Blower Motor Relay.
    3. Ignition ON.
    4. Measure:
      BJB Ground
      G08033818
      G08031601
      Auxiliary Blower Motor Relay Socket Ground
      Pin Circuit Measurement / Action Pin Circuit
      1 CBB93 (GY/BN)
      G08033411
      		 - Ground

      Is the voltage greater than 11 volts? 

      • Yes:  GO to 6  .
      • No  : VERIFY BJB fuse 93 (5A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the appropriate OEM WIRING DIAGRAMS to identify the possible causes of the circuit short.
  6. CHECK THE AUXILIARY BLOWER MOTOR RELAY COIL CONTROL CIRCUIT FOR AN OPEN
    1. Ignition OFF.
    2. Disconnect: HVAC Module C228B.
    3. Measure:
      BJB HVAC Module
      G08033818
      G08033680
      Auxiliary Blower Motor Relay Socket C228B
      Pin Circuit Measurement / Action Pin Circuit
      2 CH112 (VT/WH)
      G08031553
      		 20 CH112 (VT/WH)

      Is the resistance less than 3 ohms? 

      • Yes:  GO to 16  .
      • No  : REPAIR the circuit.
  7. CHECK THE AUXILIARY BLOWER MOTOR RELAY FUNCTIONALITY
    1. Install a known good auxiliary blower motor relay.

      Does the auxiliary blower motor function correctly? 

      • Yes:  INSTALL a new auxiliary blower motor relay.
      • No  : GO to 8  .
  8. CHECK FOR VOLTAGE AT THE AUXILIARY BLOWER MOTOR RELAY SWITCH CONTACT
    1. Disconnect: Auxiliary Blower Motor Relay
    2. Measure:
      BJB Ground
      G08033818
      G08031601
      Auxiliary Blower Motor Relay Socket Ground
      Pin Circuit Measurement / Action Pin Circuit
      3 SBB39 (WH/RD)
      G08033411
      		 - Ground

      Is the voltage greater than 11 volts? 

      • Yes:  GO to 9  .
      • No  : VERIFY BJB fuse 39 (40A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the appropriate OEM WIRING DIAGRAMS to identify the possible causes of the circuit short.
  9. CHECK VOLTAGE TO THE AUXILIARY BLOWER MOTOR WITH THE AUXILIARY BLOWER MOTOR RELAY BYPASSED
    1. Ignition OFF.
    2. Disconnect: Auxiliary Blower Motor.
    3. Disconnect: Auxiliary Blower Motor Speed Control.
    4. Connect a fused jumper:
      BJB BJB
      G08033818
      G08033818
      Auxiliary Blower Motor Relay Socket Auxiliary Blower Motor Relay Socket
      Pin Circuit Measurement / Action Pin Circuit
      3 SBB39 (WH/RD)
      G08033426
      		 5 CHA02 (BN/GN)
    5. Measure:
      Auxiliary Blower Motor Ground
      G08033833
      G08031601
      C3021 Ground
      Pin Circuit Measurement / Action Pin Circuit
      2 CHA02 (BN/GN)
      G08033411
      		 - Ground

      Is the voltage greater than 11 volts? 

      • Yes:  GO to 10  .
      • No  : REPAIR the circuit.
  10. CHECK THE AUXILIARY BLOWER MOTOR SPEED CONTROL POWER CIRCUIT FOR VOLTAGE
    1. Measure:
      Auxiliary Blower Motor Speed Control Ground
      G08033836
      G08031601
      C3002 Ground
      Pin Circuit Measurement / Action Pin Circuit
      2 CHA02 (BN/GN)
      G08033411
      		 - Ground

      Is the voltage greater than 11 volts? 

      • Yes:  DISCONNECT the fused jumper wire. CONNECT the auxiliary blower motor relay and the auxiliary blower motor speed control. GO to 11  .
      • No  : REPAIR the circuit.
  11. CHECK FOR AUXILIARY BLOWER MOTOR FUNCTIONALITY WITH A TEST LIGHT IN PLACE OF THE AUXILIARY BLOWER MOTOR
    NOTE: This step uses a test light to simulate normal circuit loads. Use only the test light recommended in the SPECIAL TOOL(S) table at the Climate Control information or equivalent. To avoid connector terminal damage, use the Flex Probe Kit for the test light probe connection to the vehicle. Do not use the test light probe directly on any connector.
    1. Connect:
      Auxiliary Blower Motor Auxiliary Blower Motor
      G08033839
      G08033839
      C3021 C3021
      Pin Circuit Measurement / Action Pin Circuit
      2 CHA02 (BN/GN) Test Light 1 VHA19 (BN)
    2. Ignition ON.
    3. Select panel mode with the auxiliary blower motor on high.

      Does the test lamp illuminate? 

  12. CHECK THE AUXILIARY BLOWER MOTOR GROUND CIRCUIT FOR AN OPEN
    1. Ignition OFF.
    2. Disconnect: Auxiliary Blower Motor Speed Control.
    3. Measure:
      Auxiliary Blower Motor Auxiliary Blower Motor Speed Control
      G08033833
      G08033836
      C3021 C3002
      Pin Circuit Measurement / Action Pin Circuit
      1 VHA19 (BN)
      G08031553
      		 1 VHA19 (BN)

      Is the resistance less than 3 ohms? 

      • Yes:  GO to 13  .
      • No  : REPAIR the circuit.
  13. CHECK THE AUXILIARY BLOWER MOTOR SPEED CONTROL GROUND CIRCUIT FOR AN OPEN
    1. Measure:
      Auxiliary Blower Motor Speed Control Ground
      G08033836
      G08031601
      C3002 Ground
      Pin Circuit Measurement / Action Pin Circuit
      6 GD149 (BK/GY)
      G08031553
      		 - Ground

      Is the resistance less than 3 ohms? 

      • Yes:  GO to 14  .
      • No  : REPAIR the circuit.
  14. CHECK THE AUXILIARY BLOWER MOTOR SPEED CONTROL COMMAND CIRCUIT FOR A SHORT TO GROUND
    1. Disconnect: HVAC Module C228B.
    2. Measure:
      HVAC Module Ground
      G08033680
      G08031601
      C228B Ground
      Pin Circuit Measurement / Action Pin Circuit
      19 CHA05 (BN/RD)
      G08031553
      		 - Ground

      Is the resistance greater than 10, 000 ohms? 

      • Yes:  GO to 15  .
      • No  : REPAIR the circuit.
  15. CHECK THE AUXILIARY BLOWER MOTOR SPEED CONTROL COMMAND CIRCUIT FOR AN OPEN
    1. Measure:
      Auxiliary Blower Motor Speed Control HVAC Module
      G08033836
      G08033680
      C3002 C228B
      Pin Circuit Measurement / Action Pin Circuit
      5 VHA25 (BN/VT)
      G08031553
      		 19 CHA05 (BN/RD)

      Is the resistance less than 3 ohms? Auxiliary Blower Motor Speed Control 

      • Yes:  INSTALL a new auxiliary blower motor speed control. REFER to Auxiliary Blower Motor Speed Control . If the concern is still present, GO to 16  .
      • No  : REPAIR the circuit.
  16. CHECK FOR CORRECT HVAC MODULE OPERATION
    1. Ignition OFF.
    2. Disconnect and inspect all HVAC module connectors.
    3. 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
    4. Reconnect the HVAC module connectors. Make sure they seat and latch correctly.
    5. Reconnect all disconnected connectors. Make sure they seat and latch correctly.
    6. Operate the system and determine if the concern is still present.

      Is the concern still present? HEATING VENTILATION AIR CONDITIONING (HVAC) MODULE - DATC

      • Yes:  CHECK OASIS  for any applicable TSBs  . If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSBs  address this concern, INSTALL a new HVAC module. REFER to HEATING VENTILATION AIR CONDITIONING (HVAC) MODULE - EMTC .
      • No  : The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.
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