Contents Wiring diagrams Section: Automatic Trans All sections

Shift Interlock System: Other Pontiac GTO IV

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Shift Lever Does Not Move with Brake Pedal Depressed

StepActionYesNo
Schematic Reference: Automatic Transmission Shift Lock Control Schematics DEFINITION: Transmission shift lever does not move with ignition ON and the brake pedal pressed.
1Did you perform the Symptoms - Automatic Transmission Shift Lock Control tests and perform all necessary inspections?Go to Step 2Go to Symptoms - Automatic Transmission Shift Lock Control
2Turn ON the ignition, with the engine OFF. Press and hold the brake pedal. Attempt to move the shift lever out of the PARK position. Does the shift lever move out of the PARK position?Go to Testing for Intermittent Conditions and Poor Connections in Wiring SystemsGo to Step 3
3Do the stop lamps operate properly?Go to Step 4Go to Diagnostic Starting Point - Lighting Systems
4Connect a test lamp between the shiftlock control solenoid feed circuit of the shiftlock control relay (terminal 4) and ground. Turn ON the ignition, with the engine OFF. Press and hold the brake pedal. Does the test lamp illuminate?Go to Step 7Go to Step 5
5Test the shift lock control relay supply voltage circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 9Go to Step 6
6Test the shift lock control relay brake switch input circuit for a short to B+. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 10
7Test the shift lock control solenoid feed circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 8
8Test the shift lock control solenoid supply voltage circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 9
9Test the shift lock control solenoid ground circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 11
10Inspect for poor connections at the shift lock control relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 12
11Inspect for poor connections at the shift lock control solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 14Go to Step 13
12Replace the shift lock control relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement?Go to Step 14
13Replace the shift lock control solenoid. Refer to Automatic Transmission Shift Lock Actuator Replacement . Did you complete the replacement?Go to Step 14
14Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Shift Lever Does Not Move with Brake Pedal Depressed

Shift Lever Can Be Moved without Brake Pedal Depressed

StepActionYesNo
Schematic Reference: Automatic Transmission Shift Lock Control Schematics DEFINITION: Transmission shift lever does not lock in the PARK position with the ignition ON and the brake pedal not pressed.
1Did you perform the Symptoms - Automatic Transmission Shift Lock Control tests and perform all the necessary inspections?Go to Step 2Go to Symptoms - Automatic Transmission Shift Lock Control
2Apply the parking brake and block the wheels. Turn ON the ignition, with the engine OFF. Attempt to move the shift lever out of the PARK position. Does the shift lever move out of the PARK position?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
3Disconnect the shift lock control relay. Attempt to move the shift lever out of the PARK position. Does the shift lever move out of the PARK position?Go to Step 6Go to Step 4
4Test the shift lock control relay brake switch input circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 5
5Test the shift lock control relay ground circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 7
6Test the shift lock control solenoid feed circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 8
7Inspect for poor connections at the shift lock control relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 9
8Inspect for poor connections at the shift lock control solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 11Go to Step 10
9Replace the shift lock control relay. Refer to Relay Replacement in Wiring Systems. Did you complete the repair?Go to Step 11
10Replace the shift lock control solenoid. Refer to Automatic Transmission Shift Lock Actuator Replacement . Did you complete the repair?Go to Step 11
11Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Shift Lever Can Be Moved without Brake Pedal Depressed