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Pinpoint Test A: Brake Shift Interlock

WARNING: This page is about a different variant/trim than selected.
  1. Refer to SHIFT INTERLOCK for schematic and connector information. Refer to TURN SIGNAL/STOP/HAZARD LAMPS for schematic and connector information.

    Normal Operation and Fault Conditions 

    The BSIA locks the selector lever in the P position until the brake pedal is pressed with the ignition on. When the brake pedal is pressed, the BPP switch, also called the stoplamp switch, closes, sending a voltage signal to the BCM and PCM. When the BCM senses voltage on this circuit, it will energize the BSIA circuit, which will retract the BSIA plunger, allowing the selector lever to be moved from P.

    BCM OSC can be used to verify BSIA operation.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    BCM B1319:11 Shift Interlock (BSI) Output Circuit: Circuit Short To Ground This DTC indicates a short to ground in the Brake Shift Interlock Actuator (BSIA) circuit.
    BCM B1319:15 Shift Interlock (BSI) Output Circuit: Circuit Short To Battery Or Open This DTC indicates an open circuit or a short to power in the Brake Shift Interlock Actuator (BSIA) circuit.

    Possible Sources 

    • Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
    • BJB fuse
    • Circuit open or shorted
    • Stoplamp switch
    • Brake Shift Interlock Actuator (BSIA)
    • BCM

  2. A1 CHECK THE OPERATION OF THE BSIA (BRAKE SHIFT INTERLOCK ACTUATOR) CIRCUIT

    • Apply the parking brake.

    • Using a diagnostic scan tool, access the BCM and use OSC to command BRK_SHIFT on and off.

    • Attempt to move the selector lever out of P with BRK_SHIFT commanded on and with BRK_SHIFT commanded off.

    Does the BSIA lock and unlock correctly as BRK_SHIFT is commanded on and off? 

    Yes  The BSIA circuit is operating properly. The concern is in the stoplamp switch circuit. GO to  A2
    No  The concern is in the BSIA circuit. GO to  A5

  3. A2 CHECK THE STOPLAMP SWITCH VOLTAGE SUPPLY CIRCUIT FOR VOLTAGE

    • Ignition OFF.

    • Disconnect BPP switch C278.

    • Inspect for damaged or pushed-out terminals.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C278-1
      GFD623860Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the voltage greater than 11 volts? 

    Yes  GO to  A3
    No  VERIFY BJB fuse F44 is OK. If the fuse is OK, REFER to OEM Electrical Wiring Diagram Introduction to identify and repair the open circuit. If the fuse is not OK, REFER to OEM Electrical Wiring Diagram Introduction to identify and repair the short to ground.

  4. A3 BYPASS THE STOPLAMP SWITCH

    • Connect a fused jumper:
      Positive Lead Measurement / Action Negative Lead
      C278-1
      GFD623862Courtesy of FORD MOTOR COMPANY
      		 C278-4

    • Ignition ON.

    • Observe the stoplamps.

    Are the stoplamps illuminated? 

    Yes  The rest of the stoplamp switch circuit is operating properly. INSTALL a new stoplamp switch. REFER to: Stoplamp Switch .
    No  GO to  A4

  5. A4 CHECK THE STOPLAMP SWITCH CIRCUIT FOR AN OPEN

    • Ignition OFF.

    • Disconnect BCM C2280A.

    • Inspect for damaged or pushed-out terminals.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C278-4
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 C2280A-1

    Is the resistance less than 3 ohms? 

    Yes  No open circuits or shorts to ground are present in the stoplamp switch circuit. GO to  A11
    No  REPAIR the open circuit.

  6. A5 CHECK THE BRAKE SHIFT INTERLOCK ACTUATOR POWER CIRCUIT FOR VOLTAGE

    • Ignition OFF.

    • Disconnect Selector Lever C3245.

    • Inspect for damaged or pushed-out terminals.

    • Ignition ON.

    • Measure the following while pressing and releasing the brake pedal:
      Positive Lead Measurement / Action Negative Lead
      C3245-12
      GFD623860Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the voltage greater than 11 volts with the brake pedal pressed and approximately 0 volts with the brake pedal released? 

    Yes  GO to  A10
    No  If the voltage is less than 11 volts when the brake pedal is pressed, GO to  A6 If voltage is present when the brake pedal is released, GO to  A8

  7. A6 CHECK THE BRAKE SHIFT INTERLOCK ACTUATOR POWER CIRCUIT FOR AN OPEN

    • Ignition OFF.

    • Disconnect BCM C2280B.

    • Inspect for damaged or pushed-out terminals.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C3245-12
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 C2280B-46

    Is the resistance less than 3 ohms? 

    Yes  GO to  A7
    No  REPAIR the open circuit.

  8. A7 CHECK THE BRAKE SHIFT INTERLOCK ACTUATOR POWER CIRCUIT FOR A SHORT TO GROUND

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C3245-12
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance greater than 10, 000 ohms? 

    Yes  The BSIA power circuit is not open or shorted to ground, but is not showing voltage coming from the BCM. GO to  A11
    No  REPAIR the short to ground.

  9. A8 CHECK THE BRAKE SHIFT INTERLOCK ACTUATOR POWER CIRCUIT FOR A SHORT TO VOLTAGE

    • Ignition OFF.

    • Disconnect BCM C2280B.

    • Inspect for damaged or pushed-out terminals.

    • Ignition ON.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C3245-12
      GFD623860Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is any voltage present? 

    Yes  REPAIR the short to power.
    No  GO to  A9

  10. A9 CHECK THE BRAKE SHIFT INTERLOCK (BSI) CIRCUIT FOR A SHORT TOGETHER WITH OTHER BCM (BODY CONTROL MODULE) CIRCUITS

    • Ignition OFF.

    • Measure the resistance between C2280B-46 and all other pins in C2280B.

    Are all the resistances greater than 10, 000 ohms? 

    Yes  A short to power is not present, but voltage is present with the BCM connected. GO to  A11
    No  REPAIR the shorted circuits.

  11. A10 CHECK THE BRAKE SHIFT INTERLOCK ACTUATOR GROUND CIRCUIT FOR AN OPEN

    • Ignition OFF.

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C3245-11
      GFD623861Courtesy of FORD MOTOR COMPANY
      		 Ground

    Is the resistance less than 3 ohms? 

    Yes  INSTALL a new selector lever. REFER to: Selector Lever Assembly .
    No  REPAIR the open circuit.

  12. A11 CHECK THE BCM (BODY CONTROL MODULE) FOR CORRECT OPERATION

    • Ignition OFF.

    • Disconnect and inspect all BCM 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

    • Connect all BCM connectors. Make sure they seat and latch correctly.

    • Operate the system and verify the concern is still present.

    Is the concern still present? 

    Yes  CHECK for an applicable TSB, GSB, SSM, or FSA. If a service bulletin exists for this concern, discontinue this test and follow bulletin instructions. If none address this concern, INSTALL a new BCM. REFER to: Body Control Module (BCM) .
    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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