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Pinpoint Test M: B10AF:11, B10AF:12, B10AF:13, B10B9:12, B10B9:14

  1. Refer to MANUAL CLIMATE CONTROL SYSTEM for schematic and connector information.

    Normal Operation and Fault Conditions 

    Air Handling, Blower motor control module REFER to: Climate Control System - Vehicles With: Electronic Manual Temperature Control (EMTC) - System Operation and Component Description

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    HVAC B10AF:11 Blower Fan Relay: Circuit Short To Ground Module senses low voltage on the relay coil voltage circuit when the module is energizing the circuit indicating a short directly to ground. Blower relay is permanently inactive.
    HVAC B10AF:12 Blower Fan Relay: Circuit Short To Battery Module senses high voltage on the relay coil voltage circuit, indicating a short directly to voltage. Blower relay is permanently inactive.
    HVAC B10AF:13 Blower Fan Relay: Circuit Open Module senses no change in voltage on the blower relay coil voltage circuit when the module is energizing the circuit, indicating an open circuit. Blower relay is permanently inactive.
    HVAC B10B9:12 Blower Control: Circuit Short To Battery Module senses high voltage on the blower motor control PWM circuit, indicating a short directly to voltage. The blower motor is inoperative.
    HVAC B10B9:14 Blower Control: Circuit Short To Ground Or Open Module senses no voltage on the blower motor control PWM circuit, indicating a short directly to ground or an open circuit. The blower motor runs at full speed if the circuit is shorted to ground. The blower motor is inoperative if the circuit is open.

    Possible Sources 

    • Fuse
    • Wiring, terminals or connectors
    • Blower motor relay [non-serviceable, part of the BJB]
    • Blower motor control module
    • HVAC control module

    Visual Inspection and Pre-checks 

    • Make sure BJB fuse 13 (40A) is OK.

  2. NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.

  3. M1 CHECK THE BLOWER MOTOR RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

    • Ignition OFF.

    • Disconnect HVAC control module C228A and C228B.

    • Disconnect BJB C1035A and C1035B.

    • Ignition ON.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C228A-11
      GFD623860Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is any voltage present? 

    Yes  REPAIR the circuit.
    No  GO to  M2

  4. M2 CHECK THE BLOWER MOTOR RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND

    • Ignition OFF.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C228A-11
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance greater than 10, 000 ohms? 

    Yes  GO to  M3
    No  REPAIR the circuit.

  5. M3 CHECK THE BLOWER MOTOR RELAY COIL CONTROL CIRCUIT FOR AN OPEN

    NOTE: Some vehicles may be equipped with a diode in the blower motor relay coil control circuit. Make sure the multimeter leads are correctly attached during testing or a false reading will occur causing misdiagnosis of the circuit. For additional information, refer to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION .

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C228A-11
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 C1035B-41

    Is the resistance less than 3 ohms? 

    Yes  GO to  M4
    No  REPAIR the circuit.

  6. M4 CHECK THE BLOWER MOTOR RELAY COIL GROUND CIRCUIT FOR AN OPEN

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C1035A-6
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance less than 3 ohms? 

    Yes  GO to  M5
    No  REPAIR the circuit.

  7. M5 CHECK THE BLOWER MOTOR CONTROL MODULE VOLTAGE CIRCUIT FOR AN OPEN

    • Disconnect Blower motor control module C297.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C297-1
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 C1035A-31

    Is the resistance less than 3 ohms? 

    Yes  GO to  M6
    No  REPAIR the circuit.

  8. M6 CHECK THE BLOWER MOTOR CONTROL MODULE GROUND CIRCUIT FOR AN OPEN

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C297-6
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance less than 3 ohms? 

    Yes  GO to  M7
    No  REPAIR the circuit.

  9. M7 CHECK FOR VOLTAGE TO THE BLOWER MOTOR CONTROL MODULE

    • Connect BJB C1035A and C1035B.

    • Connect HVAC control module C228A and C228B.

    • Ignition ON.

    • Select PANEL on the HVAC controls.

    • Select the highest blower motor setting.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C297-1
      GFD623860Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the voltage greater than 11 volts? 

    Yes  GO to  M8
    No  VERIFY BJB fuse 13 (40A) is OK. If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify the possible causes of the circuit short. If OK, INSTALL a new BJB.

  10. M8 CHECK THE BLOWER MOTOR CONTROL MODULE PWM (PULSE WIDTH MODULATION) CIRCUIT FOR A SHORT TO VOLTAGE

    • Ignition OFF.

    • Disconnect HVAC control module C228A and C228B.

    • Ignition ON.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C297-2
      GFD623860Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is any voltage present? 

    Yes  REPAIR the circuit.
    No  GO to  M9

  11. M9 CHECK THE BLOWER MOTOR CONTROL MODULE PWM (PULSE WIDTH MODULATION) CIRCUIT FOR AN OPEN

    • Ignition OFF.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C297-2
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 C228A-23

    Is the resistance less than 3 ohms? 

    Yes  GO to  M10
    No  REPAIR the circuit.

  12. M10 CHECK FOR CORRECT BLOWER MOTOR CONTROL MODULE OPERATION

    • Ignition OFF.

    • Disconnect and inspect the blower motor control module connector.

    • 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 disconnected 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  INSTALL a new blower motor control module. REFER to: Blower Motor Control Module  CLEAR all Diagnostic Trouble Codes (DTCs). CARRY OUT the HVAC control module self-test. TEST the system for normal operation. If the concern is still present, GO to  M11
    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.

  13. M11 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE OPERATION

    • Ignition OFF.

    • Disconnect and inspect all HVAC control module electrical connectors (if not previously disconnected).

    • Repair:

      • corrosion (install new connector or terminal - clean module pins)
      • damaged or bent pins - install new terminals or pins
      • pushed-out pins - install new pins as necessary

    • Connect all HVAC control module electrical 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 service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new HVAC control module. REFER to: Heating, Ventilation and Air Conditioning (HVAC) Control Module 
    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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