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For 1990-2009 cars only

Ignition Can/Cannot Be Turned Off with Transmission in Any Gear without RPO Y41

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.

Circuit/System Description

The body control module (BCM) controls voltage to the ignition lock cylinder actuator. When the gearshift is in PARK, the park position switch is closed. This grounds the circuit allowing the lock cylinder actuator to retract the pin. This allows the ignition lock cylinder to be turned to the LOCK position. When the gearshift is not in PARK, the park position switch is open, and the spring loaded pin is in the out position. This prevents the ignition lock cylinder from being turned to LOCK.

Reference Information

Schematic Reference

Ignition Lock Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electronic Park Lock Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

  1. Ignition OFF, disconnect the harness connector at the park switch.
  2. Ignition OFF, test for less than 5 Ω of resistance between the ground circuit and ground.
  3. If greater than the specified range, test the circuit for an open/high resistance.
  4. Ignition OFF, disconnect the harness connector at the ignition lock cylinder control actuator.
  5. Ignition ON, verify a test lamp illuminates between the control circuit terminal 2 and ground.
  6. If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  7. Connect a test lamp between the control circuit terminal 1 and the control circuit terminal 2.
  8. Ignition ON, cycle the gear shift from PARK to DRIVE. The test lamp should turn ON and OFF when cycled between gears.
  9. If the test lamp is always ON, test the control circuit for a short to ground. If circuit tests normal, replace the park switch.
    If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the park switch.
  10. If all circuits test normal, replace the ignition lock cylinder control actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Ignition and Start Switch Replacement
    •  Transmission Control Replacement
    •  Control Module References for BCM replacement, setup, and programming

Ignition Can/Cannot Be Turned Off with Transmission in Any Gear with RPO Y41

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.

Circuit/System Description

The remote control door lock receiver (RCDLR) controls voltage to the ignition lock cylinder actuator. When the gearshift is in PARK, the park position switch is closed. This grounds the circuit allowing the lock cylinder actuator to retract the pin. This allows the ignition lock cylinder to be turned to the LOCK position. When the gearshift is not in PARK, the park position switch is open, and the spring loaded pin is in the out position. This prevents the ignition lock cylinder from being turned to LOCK.

With the keyless access transmitter inside the vehicle, it can be started one of two ways:

  1. Push the ignition control knob in and turn.
  2. Depress the brake pedal and turn the ignition control knob, (this method does not require pushing the knob in).

If the RCDLR is asleep, depressing the brake pedal will not wakeup it up and the vehicle will not start. To wake up the RCDLR, open and close the driver’s door, or use method 1 to start the vehicle. Pushing the ignition control knob in will wake up the RCDLR.

Diagnostic Aids

    • The steering wheel may need to be tilted as the steering column wire harness may block the ignition actuator.
    • If pushing in the ignition control knob to start, ensure the knob is pushed in first and then turned. Turning the knob first may bind the actuator.
    • If pressing the brake pedal to start, ensure that the pedal is pushed first then the knob is turned. Turning the knob first may bind the actuator.

Reference Information

Schematic Reference

Ignition Lock Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electronic Park Lock Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition OFF, disconnect the harness connector at the park switch.
  2. Ignition OFF, test for less than 5 Ω of resistance between the ground circuit and ground.
  3. If greater than the specified range, test the circuit for an open/high resistance.
  4. Ignition OFF, disconnect the harness connector at the ignition lock cylinder control actuator.
  5. Place a known good, working keyless access transmitter in the interior of the vehicle. Push the ignition control knob in to request authentication. Ignition ON, verify a test lamp illuminates between the control circuit terminal 2 and ground.
  6. If the test lamp does not illuminate, test the control circuit from the RCDLR for a short to ground or an open/high resistance. If the circuit tests normal, replace the RCDLR.
  7. Connect a test lamp between the control circuit terminal 1 and the control circuit terminal 2 of the ignition lock cylinder control actuator.
  8. Ignition ON, cycle the gear shift from PARK to DRIVE. The test lamp should turn ON and OFF when cycled between gears.
  9. If the test lamp is always ON, test the control circuit for a short to ground. If all circuit tests normal, replace the park switch.
    If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the park switch.
  10. If all circuits test normal, replace the ignition lock cylinder control actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Ignition and Start Switch Replacement
    •  Transmission Control Replacement
    •  Control Module References for RCDLR replacement, setup, and programming