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Pinpoint Test A: The Shift Interlock System Does Not Release/Lock Correctly

WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
  1. A1 TEST THE BRAKE LIGHTS 
    • Apply the brake pedal and view the brake lights.
    • Do the brake lights illuminate? 
  2. A2 TEST FUSE C34 (30A) 
    • Check fuse: Fuse C34 (30A) Power Distribution Box.
    • Is the resistance of the fuse 5 ohms or less? 
  3. A3 TEST FUSE C18(10A) 
    • Check fuse: Fuse C18 (10A) Smart Junction Box.
    • Is the resistance of the fuse 5 ohms or less? 
  4. A4 TEST CIRCUIT 1050 (LG/PK) FOR SHORT TO GROUND 
    • Disconnect: Ignition Switch C250.
    • Measure the resistance between ignition switch C250 pin 1, circuit 1050 (LG/PK) harness side and ground.
      Fig 1: Testing Circuit 1050 (LG/PK) For Short To Ground
      G03991949Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    • Yes  : GO to A5.
    • No  : REPAIR circuit 1050 (LG/PK). TEST the system for normal operation.
  5. A5 TEST CIRCUIT 1050 (LG/PK) FOR AN OPEN 
    • Disconnect: Ignition Switch C250.
    • Disconnect: Smart Junction Box (SJB) C2280b.
    • Measure the resistance between SJB C2280b pin 32, circuit 1050 (LG/PK), harness side and ignition switch C250 pin 1, harness side.
      Fig 2: Testing Circuit 1050 (LG/PK) For An Open
      G03991950Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    • Yes  : GO to A6.
    • No  : REPAIR circuit 1050 (LG/PK). TEST the system for normal operation.
  6. A6 TEST CIRCUIT 1140e (PK) FOR BATTERY VOLTAGE 
    • Key in OFF position.
    • Disconnect: Brake Pedal Position (BPP) Switch C278.
    • Measure the voltage between BPP switch C278 pin 1, circuit 1140e (PK), harness side and ground.
      Fig 3: Testing Circuit 1140E (PK) For Battery Voltage
      G03991951Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 
    • Yes  : GO to A7.
    • No  : REPAIR circuit 1140e (PK). TEST the system for normal operation.
  7. A7 TEST CIRCUIT 1140e (PK) FOR A SHORT TO GROUND 
    • Disconnect: Brake Pedal Position (BPP) Switch C278.
    • Measure the resistance between BPP switch C278 pin 2, circuit 1140e (PK), harness side and ground.
      Fig 4: Testing Circuit 1140E (PK) For Short To Ground
      G03991952Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    • Yes  : GO to A8.
    • No  : REPAIR circuit 1140e (PK). TEST the system for normal operation.
  8. A8 TEST CIRCUIT 1140e (PK) FOR AN OPEN 
    • Disconnect: Smart Junction Box (SJB) C265.
    • Measure the resistance between SJB C2280a pin 27 and BPP switch C278 pin 2, circuit 1140e (PK), harness side.
      Fig 5: Testing Circuit 1140E (PK) For An Open
      G03991953Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    • Yes  : GO to A9.
    • No  : REPAIR circuit 1140e (PK). TEST the system for normal operation.
  9. A9 TEST THE BRAKE PEDAL POSITION (BPP) SWITCH 
    • Measure the resistance between BPP switch C278 pin 1 and pin 2, while OPEN (off) and CLOSED (on).
      Fig 6: Testing Brake Pedal Position (BPP) Switch
      G03991954Courtesy of FORD MOTOR CO.
    • Is the resistance of the switch greater than 10,000 ohms while OFF and 5 ohms or less while ON? 
    • Yes  : GO to A10.
    • No  : INSTALL a new BPP switch. TEST the system for normal operation.
  10. A10 TEST CIRCUIT 810 (RD/LG) FOR A SHORT TO GROUND 
    • Disconnect: Floor Shifter Harness Assembly C3245.
    • Measure the resistance between floor shifter harness assembly C3245 pin 1, circuit 810 (RD/LG), harness side and ground.
      Fig 7: Testing Circuit 810 (RD/LG) For Short To Ground
      G03991955Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    • Yes  : GO to A11.
    • No  : REPAIR circuit 810 (RD/LG). TEST the system for normal operation.
  11. A11 TEST CIRCUIT 810 (RD/LG) FOR AN OPEN 
    • Measure the resistance between BPP switch C278 pin 1, circuit 810 (RD/LG), harness side and floor shifter harness assembly C3245 pin 1, circuit 810 (RD/LG), harness side.
      Fig 8: Testing Circuit 810 (RD/LG) For An Open
      G03991956Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    • Yes  : GO to A12.
    • No  : REPAIR circuit 810. TEST the system for normal operation.
  12. A12 TEST CIRCUIT 810 (RD/LG) FOR BATTERY VOLTAGE 
    • Connect: Brake Pedal Position (BPP) Switch C278.
    • Disconnect: Floor Shifter Harness Assembly C3245.
    • Depress the brake pedal.
    • Measure the voltage on floor shifter harness assembly C3245 pin 1, circuit 810 (RD/LG), harness side and ground.
      Fig 9: Testing Circuit 810 (RD/LG) For Battery Voltage
      G03991957Courtesy of FORD MOTOR CO.
    • Is the voltage greater than 10 volts? 
    • Yes  : REPAIR circuit 810 (RD/LG). TEST the system for normal operation.
    • No  : GO to A13.
  13. A13 TEST CIRCUIT 409 (TN/BK) FOR A SHORT TO GROUND 
    • Disconnect: Floor Shifter Harness Assembly C3245.
    • Measure the resistance between floor shifter harness assembly C3245 pin 8, circuit 409 (TN/BK), harness side and ground.
      Fig 10: Testing Circuit 409 (TN/BK) For Short To Ground
      G03991958Courtesy of FORD MOTOR CO.
    • Is the resistance less than 10,000 ohms? 
    • Yes  : REPAIR circuit 409 (TN/BK). TEST the system for normal operation.
    • No  : GO to A14.
  14. A14 TEST CIRCUIT 409 (TN/BK) FOR AN OPEN 
    • Disconnect: Ignition Switch C250.
    • Disconnect: Floor Shifter Harness Assembly C3245.
    • Measure the resistance between floor shifter harness assembly C3245 pin 8, and ignition switch C250 pin 3, circuit 409 (TN/BK), harness side.
      Fig 11: Testing Circuit 409 (TN/BK) For An Open
      G03991959Courtesy of FORD MOTOR CO.
    • Is the resistance less than 5 ohms? 
    • Yes  : REPAIR circuit 409 (TN/BK). TEST the system for normal operation.
    • No  : GO to A15.
  15. A15 TEST CIRCUIT 1205NZ (BK) FOR A SHORT TO GROUND 
    • Disconnect: Floor Shifter Harness Assembly C3245.
    • Measure the resistance between floor shifter harness assembly C3245 pin 4, circuit 1205NZ (BK), harness side and ground.
      Fig 12: Testing Circuit 1205NZ (BK) For Short To Ground
      G03991960Courtesy of FORD MOTOR CO.
    • Is the resistance greater than 10,000 ohms? 
    • Yes  : INSTALL a new shifter, REFER to SELECTOR LEVER . TEST the system for normal operation.
    • No  : REPAIR circuit 1205NZ (BK). TEST the system for normal operation.
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