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

WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

A1 CHECK FUSE F5 (10A)
- Key in OFF position.
- Check fuse: CJB Fuse F5 (10A).
- Is the resistance less than 5 ohms?
Yes : GO to A3.

No : GO to A2.
A2 CHECK CIRCUIT 22 (LB/BK) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: CJB Fuse F5 (10A).
- Disconnect: Deactivation Switch C277.
- Keep brake pedal position switch C278 connected.
- Measure the resistance between the output side of fuse F5 (10A) and ground.
  
  Fig 1: Measuring Resistance Between Output Side Of Fuse F5 (10A) And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
Yes : GO to A5.

No : REPAIR circuit 22 (LB/BK). RECONNECT all components. TEST the system for normal operation.
A3 CHECK CIRCUIT 22 (LB/BK) FOR AN OPEN
- Disconnect: CJB Fuse F5 (10A).
- Disconnect: Brake Pedal Position Switch C278.
- Measure the resistance between the output side of fuse F5 (10A) and brake pedal position switch C278-3.
  
  Fig 2: Measuring Resistance Between Output Side Of Fuse F5 (10A) And Brake Pedal Position Switch C278-3
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to A4.

No : REPAIR circuit 22 (LB/BK). RECONNECT all components. TEST the system for normal operation.
A4 CHECK THE BRAKE PEDAL POSITION SWITCH
- Measure the resistance of brake pedal position switch C278, while open (OFF) and closed (ON).
  
  Fig 3: Measuring Resistance Of Brake Pedal Position Switch C278
  Courtesy of FORD MOTOR CO.
- Is resistance of the switch greater than 10,000 ohms while OFF and less than 5 ohms while ON?
Yes : GO to A6.

No : INSTALL a new brake pedal position switch. RECONNECT all components. TEST the system for normal operation.
A5 CHECK CIRCUIT 1651 (WH/RD) FOR A SHORT TO GROUND
- Disconnect: Brake Pedal Position Switch C278.
- Disconnect: Lighting Control Module C2145b.
- Disconnect: ABS Control Module C135.
- Measure the resistance between brake pedal position switch C278-4 and ground.
  
  Fig 4: Measuring Resistance Between Brake Pedal Position Switch C278-4 And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
Yes : GO to A8.

No : REPAIR circuit 1651 (WH/RD). RECONNECT all components. TEST the system for normal operation.
A6 CHECK CIRCUIT 1651 (WH/RD) FOR AN OPEN
- Disconnect: Lighting Control Module C2145b.
- Measure the resistance between brake pedal position switch C278-4 and lighting control module C2145b-5.
  
  Fig 5: Measuring Resistance Between Brake Pedal Position Switch C278-4 And Lighting Control Module C2145B-5
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to A7.

No : REPAIR circuit 1651 (WH/RD). RECONNECT all components. TEST the system for normal operation.
A7 CHECK CIRCUIT 1651 (WH/RD) FOR A SHORT TO POWER
- Measure the voltage at brake pedal position switch C278-4.
  
  Fig 6: Measuring Voltage Brake Pedal Position Switch C278-4
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes : REPAIR circuit 1651 (WH/RD) for a short to power. RECONNECT all components. TEST the system for normal operation.

No : GO to A9.
A8 CHECK CIRCUIT 810 (RD/LG) FOR A SHORT TO GROUND
- Disconnect: Lighting Control Module C2145A.
- Disconnect: Brake Shift Interlock C2008.
- Measure the resistance between shift interlock actuator C2008-2 and ground.
  
  Fig 7: Measuring Resistance Between Shift Interlock Actuator C2008-2 And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
Yes : INSTALL a new lighting control module. REFER to MULTIFUNCTION ELECTRONIC MODULES . RECONNECT all components. TEST the system for normal operation.

No : REPAIR circuit 810 (RD/LG). RECONNECT all components. TEST the system for normal operation.
A9 CHECK CIRCUIT 810 (RD/LG) FOR AN OPEN
- Measure the resistance between lighting control module C2145A-6 and brake shift interlock actuator C2008-2.
  
  Fig 8: Measuring Resistance Between Lighting Control Module C2145A-6 And Brake Shift Interlock Actuator C2008-2
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to A10.

No : REPAIR circuit 810 (RD/LG). RECONNECT all components. TEST the system for normal operation.
A10 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Measure the resistance between shift interlock actuator C2008-1 and ground.
  
  Fig 9: Measuring Resistance Between Shift Interlock Actuator C2008-1 And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to A11.

No : REPAIR circuit 57 (BK) for an open. RECONNECT all components. TEST the system for normal operation.
A11 CHECK THE LIGHTING CONTROL MODULE
- Connect: Lighting Control Module C2145a.
- Connect: Lighting Control Module C2145b.
- Connect: Brake Pedal Position Switch C278.
- Connect: CJB Fuse F5 (10A).
- Key in ON position.
- Measure the voltage at shift interlock actuator C2008-2 while applying pressure to the brake pedal.
  
  Fig 10: Measuring Voltage At Shift Interlock Actuator C2008-2 And Brake Pedal
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes : INSTALL a new shift interlock actuator. REFER to BRAKE SHIFT INTERLOCK ACTUATOR - COLUMN SHIFT . TEST the system for normal operations.

No : INSTALL a new lighting control module. REFER to MULTIFUNCTION ELECTRONIC MODULES . RECONNECT all components. TEST the system for normal operation.