Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Park Lock Solenoid Control | 1 | 1 | -- | -- |
A/T Shift Lock Control Solenoid Control | 1 | 1 | 2 | -- |
A/T Shift Lock Control Ground | -- | 1 | -- | -- |
1. Gear shift selector will not move from the PARK position with brake applied 2. Gear shift selector moves from the PARK position w/o brake applied | ||||
Circuit/System Description
With the ignition in the OFF or ACCY position, the park lock solenoid is de-energized and locks the shift lever in the park position. With the ignition in the ON position, voltage is supplied to the park lock solenoid. The park lock solenoid energizes through a permanent ground unlocking the shift lever.
With the ignition in the ON position, voltage is supplied to the stop lamp switch. Voltage flows through the normally closed contacts of the switch to the automatic transmission shift lock control solenoid. The automatic transmission shift lock control solenoid is permanently grounded. This energizes the automatic transmission shift lock control solenoid causing the transmission shift lever to be physically locked in the PARK position. When the brake pedal is depressed, the contacts in the stop lamp switch open de-energizing the automatic transmission shift lock control solenoid. This allows the shift lever to be move out of the PARK position.
Diagnostic Aids
If the automatic transmission shift lock control circuit is open, the A/T shift lock solenoid will be inoperative. The vehicle will shift out of PARK without depressing the brake pedal.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Automatic Transmission Shift Lock Control Description and Operation
Electrical Information Reference
Circuit/System Verification
Ignition ON, vehicle in PARK, verify the transmission range selector displays PARK.
| ⇒ | If not the specified value, refer to Range Selector Displays Incorrect Range . |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the stop lamp switch.
- Ignition ON, vehicle in PARK, verify that a test lamp illuminates between the control circuit terminal F and ground.
- Ignition OFF, connect the harness connector at the stop lamp switch. Disconnect the harness connector at the automatic transmission shift lock actuator.
- Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal A and ground.
- Ignition ON, verify that a test lamp illuminates between the control circuit terminal B and ground.
- With the brake pedal pressed, verify that a test lamp illuminates between the control circuit terminal E and ground.
- With the brake pedal released, verify that a test lamp does not illuminate between the control circuit terminal E and ground.
- If all circuits test normal, test or replace the automatic transmission shift lock actuator.
| ⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit test normal, test or replace the stop lamp switch. |
| ⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
Component Testing
- Install a 10A fused jumper wire from 12 volts to the automatic transmission shift lock actuator control circuit terminals B and E. Momentarily connect a jumper wire from ground to terminal A.
- Listen for the solenoids to turn ON and OFF.
| ⇒ | If the function does not perform as specified, replace the automatic transmission shift lock actuator. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
