Most likely a problem with the
Shift Interlock System
The shift interlock system prevents the shifting from PARK unless the brake pedal (2455) is depressed. The shift interlock system consists of a shift lock actuator (3Z719) mounted at the base of the steering column tube (3514). If the ignition switch (11572) is in the RUN position, the shift lock actuator is continually on unless the brake pedal is depressed.
Could have a bad brake switch , do the brake lights work ?
Inspection and Verification
- Verify the customer concern by operating the transmission external control.
- Visually inspect for obvious signs of mechanical and electrical damage, incorrect component installation, and component misalignment. Verify that all circuit-related systems are functioning correctly. Refer to the following chart:
Visual Inspection Chart
Mechanical
Electrical
- Damaged shift lock actuator
- Damaged brake pedal position switch
- Damaged steering column
- Damaged transmission control switch
- Damaged instrument cluster
- Damaged shift cable and bracket
- Failed fuse(s)
- Damaged wiring harness
- Loose or corroded connections
- If the fault is not visually evident, proceed to the Symptom Chart
SYMPTOM CHART
Condition
Possible Sources
Action
- Shift Interlock System Does Not Release/Lock Properly
- Circuit(s).
- Fuse(s).
- Shift lock actuator.
- Brake pedal position (BPP) switch.
PINPOINT TEST A: THE SHIFT INTERLOCK SYSTEM DOES NOT RELEASE/LOCK CORRECTLY
CONDITIONS
DETAILS/RESULTS/ACTIONS
A1 TEST FUSE 10 (7.5A)
Fuse 10 (7.5A)
Measure the resistance of fuse 10.
- Is the resistance 5 ohms or less?
Yes GO to A2 .
No GO to A3 .
A2 CHECK THE POWER SUPPLY TO THE SHIFT LOCK ACTUATOR-CIRCUIT 1003 (GY/YE)
Shift Lock Actuator C289
Measure the voltage between the shift lock actuator C289 pin 3, circuit 1003 (GY/YE), harness side and ground.
- Is the voltage greater than 10 volts?
Yes GO to A5 .
No GO to A4 .
A3 TEST CIRCUIT 1003 (GY/YE) FOR SHORT TO GROUND
Shift Lock Actuator C289
Measure the resistance at C289 pin 3, circuit 1003 (GY/YE).
- Is the resistance 10 K ohms or less?
Yes REPAIR circuit 1003 (GY/YE) for short to ground. TEST the system for normal operation.
No INSTALL a new shift lock actuator. TEST the system for normal operation.
A4 TEST CIRCUIT 1003 (GY/YE) FOR OPEN
Measure the resistance of circuit 1003 (GY/YE) between the output side of fuse 10 (7.5A) and the shift lock actuator C289 pin 3.
- Is the resistance 5 ohms or less?
Yes GO to A5 .
No REPAIR circuit 1003 (GY/YE) for open. TEST the system for normal operation.
A5 CHECK FUSE 9 (7.5A)
Fuse 9 (7.5A)
Measure the resistance of fuse 9 (7.5A).
- Is the resistance 5 ohms or less?
Yes GO to A8 .
No GO to A6 .
A6 TEST CIRCUIT 276 (BN) FOR SHORT TO GROUND.
Brake Pedal Position (BPP) Switch C224
Measure the resistance of circuit 276 (BN) between C224 pin 3 and ground.
- Is the resistance 10 K ohms or less?
Yes REPAIR circuit 276 (BN) for short to ground. TEST the system for normal operation.
No GO to A7 .
A7 TEST CIRCUIT 810 (RD/LG) FOR SHORT TO GROUND
Shift Lock Actuator C289
Depress the brake pedal and measure the resistance between C289 pin 1 and ground.
- Is the resistance 10 K ohms or less?
Yes REPAIR circuit 810 (RD/LG) for short to ground. TEST the system for normal operation.
No INSTALL a new shift lock actuator. TEST the system for normal operation.
A8 CHECK FOR B+ ON CIRCUIT 810 (RD/LG)
Shift Lock Actuator C289
Depress the brake pedal and measure voltage at C289 pin 1.
- Is the voltage 10 volts or greater?
Yes GO to A12 .
No GO to A9 .
A9 TEST CIRCUIT 276 (BN) FOR OPEN
Brake Pedal Position (BPP) Switch C224
Measure the resistance between the output side of fuse 9 (7.5A) and the brake pedal position switch pin 3, circuit 276 (BN).
- Is the resistance 5 ohms or less?
Yes GO to A10 .
No REPAIR circuit 276 (BN) for open. TEST the system for normal operation.
A10 TEST BRAKE PEDAL POSITION SWITCH
Measure the resistance of the brake pedal position switch, while open (OFF) and closed (ON), between pin 2 and pin 3 of C224.
- Is the resistance of the switch greater than 10 K ohms while OFF and 5 ohms or less while ON?
Yes GO to A11 .
No INSTALL a new switch. TEST the system for normal operation.
A11 TEST CIRCUIT 810 (RD/LG) FOR OPEN
Brake Pedal Position (BPP) Switch C224
Shift Lock Actuator C289
Measure the resistance between C224 pin 2 and C289 pin 1.
- Is the resistance 5 ohms or less?
Yes INSTALL a new shift lock actuator. TEST the system for normal operation
No REPAIR circuit 810 (RD/LG) for open. TEST the system for normal operation.
A12 CHECK CIRCUIT 57 (BK) FOR AN OPEN
Measure the resistance between the shift lock actuator C289 pin 2, circuit 57 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes INSTALL a new shift lock actuator. REFER to Brake Shift Interlock Actuator in this section. TEST the system for normal operation.
No REPAIR circuit 57 (BK). RECONNECT all components. TEST the system for normal