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Key won’t come out of ignition lock

I can’t get my key out of ignition lock

This article addresses the follow issues on GM vehicles: key wont come out ignition, won’t shift out of park, shifter won’t return to park.

All late model vehicles are required to have a shift interlock feature that prevents you from shifting out of park unless the brake pedal is depressed. When you press on the brake, a shifter interlock solenoid activates and pulls a locking pin out of the way allowing you to shift out of park. If vehicles with the shifter on the steering column, the shift interlock solenoid is also located in the column. For floor mounted shifters, the solenoid is in the console near the shifter. shift interlock solenoid

If you have a problem with the brake light switch and the shifter won’t shift out of park, consult your owner’s manual to read up on how to do a manual override. In some cases the vehicle may have a plastic cover that can be removed with a key. Once the cover is removed, you can activate a manual override. Other vehicles have a slot in which you can insert the key. When you press down on the key, it pushes a lever unlocking the shifter and allowing you to shift out of park. None of these manual overrides fixes the underlying problem, but can get you going in order to get the vehicle to a shop for repair. The fix is to examine the brake light switch to confirm it’s working (working brake lights does NOT automatically mean the brake pedal switch is working—there may be more than one switch connecting to the brake pedal).

shift interlock solenoidIn addition to a shift interlock safety feature some vehicles have a stop disable feature that prevents you from shutting off the vehicle while the transmission is in a drive or reverse gear. In the first iterations of this system, car makers used a cable to connect the shifter to the ignition lock cylinder to prevent your from rotating the ignition to the off position. In cases where key wont come out ignition, the fault is usually with a binding or out of adjustment shift cable. Consult a shop manual to find the adjustment procedure.

In later iterations, car makers (especially GM) resorted to electronic means to prevent inadvertently shutting off the engine while in a driver gear. Specifically, GM used an

Ignition Lock Cylinder Control Actuator for vehicles equipped with a floor mounted console gear shifter. The ignition lock cylinder control actuator system is in the steering column and contains a pin that is spring loaded in the out position to mechanically prevent the ignition key cylinder from being turned to the Lock position when vehicle transmission is not in the Park position. The lock cylinder actuator works with a park position switch that is located in the transmission shift lock control switch.

The automatic transmission park lock control system is controlled by the body control module (BCM) and activates with a power application to the solenoid. This happens when the BCM senses you depressing the brake pedal.

When you turn the ignition key to the on position the GM engine control system checks to make sure the vehicle is in PARK. It then sends a digital signal to the BCM indicating it should look for a brake pedal signal. If the BCM sees a brake pedal signal, it supplies voltage to the automatic transmission park lock control solenoid, unlocking the park lever allowing the driver to move the park lever out of the PARK position as the solenoid energizes. When the brake pedal is not applied, the body control module turns the control voltage output of the park lock control solenoid OFF, de-energizing the parklock control solenoid. The de-energized solenoid mechanically locks the park lever in the PARK position.

If vehicle power is lost, and/or the transmission is not in the Park position you can’t remove the key from the lock cylinder and in some cases you cannot shift the gears. That’s due to electronic shifting. In late model vehicles, car makers discarded the mechanical shift cable and instead use an electronic shift switch to notify the ECM of your selected gear.

If you can’t move the shift lever out of park, check the brake pedal switch and the shift interlock solenoid.

If you can’t remove the key from the lock cylinder, chances are the automatic transmission park lock control solenoid is inoperative, jammed, or has a wiring harness failure. The same issues can appear as a shifter won’t change gears symptom.

© 2015 Rick Muscoplat

Posted on by Rick Muscoplat

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