2013 Subaru Impreza Key Stuck In Ignition

Alright, let's talk about that frustrating "key stuck in the ignition" problem on your 2013 Subaru Impreza. It's a fairly common issue, and while it can seem daunting, often it's fixable with some careful troubleshooting and a methodical approach. This guide is aimed at the experienced DIYer, so we'll dive into the technical details but keep the explanation clear.

Understanding the System: Interlock Mechanics

Before we start poking around, it's crucial to understand how your key is designed to release. Modern vehicles use a system called an ignition interlock. This system prevents you from removing the key unless certain conditions are met. The primary condition, of course, is that the transmission must be in the Park (P) position. This is a safety feature designed to prevent roll-aways.

The core of the interlock system in your Impreza typically involves these components:

Ignition Switch Cylinder: The physical housing where you insert the key. It contains tumblers and electrical contacts.
Shift Interlock Solenoid: A small electromagnet located near the shifter. When energized, it allows the shift lever to move out of Park.
Shift Cable: The mechanical linkage connecting the shift lever to the transmission.
Transmission Range Sensor (TRS): This sensor, sometimes called a Neutral Safety Switch, tells the car's computer (the ECU) what gear you're in. It's usually mounted on the transmission.
Brake Switch: Activated when you press the brake pedal. Some systems require the brake to be engaged to shift out of Park.
ECU (Engine Control Unit): The car's computer, which receives input from the TRS, brake switch, and other sensors to determine when it's safe to release the key.

When everything's working correctly, here's the sequence:

You shift into Park.
The Transmission Range Sensor sends a signal to the ECU confirming the car is in Park.
The ECU de-energizes the shift interlock solenoid.
A mechanical linkage is released (either directly or through a cable), allowing the ignition cylinder to rotate fully and release the key.

The problem occurs when one or more of these steps breaks down.

Troubleshooting Steps: Diagnosing the Problem

Let's get our hands dirty and figure out what's causing the key to stick. Always start with the easiest and most common causes:

1. Verifying Park Position and Shifter Adjustment

This sounds basic, but it's often the culprit. Sometimes, the shift lever isn't fully engaging Park, even if it appears to be. This can happen due to slight cable stretch or misalignment.

Try Shifting Vigorously: Firmly move the shift lever all the way into Park, then try to remove the key. Sometimes a little extra force is all it takes.
Check Shifter Cable Adjustment: Locate the shifter cable under the console (you'll likely need to remove some trim pieces – consult your service manual for specific instructions). Look for an adjustment mechanism (usually a threaded rod or a cable clamp). Loosen the adjuster slightly and try moving the shift lever through its full range, ensuring it clicks positively into Park. Retighten the adjuster, making sure the lever feels solid in Park.

2. Examining the Brake Switch

As mentioned earlier, some interlock systems rely on the brake switch signal. If the brake switch is faulty, the ECU might not register that you're pressing the brake pedal, preventing the key from releasing.

Check Brake Lights: Confirm that your brake lights illuminate when you press the brake pedal. If they don't, the brake switch is likely the problem.
Test the Brake Switch: The brake switch is usually located near the brake pedal arm. You can test it with a multimeter. Disconnect the switch connector and use the multimeter in continuity mode. With the brake pedal released, you should have an open circuit. Press the brake pedal, and the circuit should close (showing continuity). If it doesn't work as expected, replace the brake switch.

3. Investigating the Shift Interlock Solenoid

The shift interlock solenoid physically prevents the shift lever from moving out of Park unless it's energized. If the solenoid is stuck or faulty, it can prevent the key from releasing.

Locate the Solenoid: Consult your Impreza's wiring diagram (available in the service manual) to find the exact location of the shift interlock solenoid. It's typically near the shifter assembly.
Listen for Clicking: With the ignition on (engine off), shift into Park and then press the brake pedal. You should hear a faint click from the solenoid as it engages and disengages. If you don't hear anything, it might be the solenoid itself or a wiring issue.
Test the Solenoid with a Multimeter: Disconnect the solenoid connector and use a multimeter to check its resistance. A typical solenoid should have a resistance value between 20 and 100 ohms (check your service manual for the specific range for your Impreza). An open circuit (infinite resistance) indicates a faulty solenoid.
Check for Voltage: With the connector plugged in, use a multimeter to check for voltage at the solenoid connector when the brake pedal is pressed and the car is in Park. You should see approximately 12 volts. If you don't, there's a problem with the wiring or the ECU.

4. Transmission Range Sensor (TRS) Issues

The TRS is crucial because it tells the ECU what gear the car is in. A faulty TRS or a wiring problem can prevent the ECU from knowing the car is in Park, leading to the key getting stuck.

Visual Inspection: Locate the TRS on the transmission (refer to your service manual). Check the wiring and connector for any signs of damage, corrosion, or loose connections.
Testing with a Multimeter: The TRS has multiple pins, and each pin corresponds to a specific gear position. Use your service manual to identify the correct pins and test for continuity in each gear position. The manual will specify which pins should have continuity in each gear. If the readings are incorrect, the TRS might be faulty. Replacing the TRS often requires removing the transmission pan, so be prepared for an oil change.

5. Ignition Cylinder Problems

While less common, the ignition cylinder itself can sometimes be the source of the issue. Worn tumblers or debris inside the cylinder can prevent the key from rotating freely.

Lubrication: Try spraying a small amount of graphite lubricant (designed for locks) into the ignition cylinder. Work the key in and out a few times to distribute the lubricant.
Key Condition: Examine your key for any damage or wear. A bent or worn key can sometimes cause problems. Try using a spare key if you have one.
Professional Help: If lubrication doesn't work and the key appears damaged, consider taking the ignition cylinder to a locksmith for inspection and possible repair or replacement. Replacing the ignition cylinder can be complex and may require specialized tools.

6. ECU Issues (Last Resort)

In rare cases, a faulty ECU can cause the key to get stuck. However, before suspecting the ECU, rule out all other possibilities. ECU diagnosis and repair typically require specialized equipment and expertise, so it's best left to a professional.

Important Considerations

Service Manual: Invest in a good service manual for your 2013 Subaru Impreza. It will provide detailed wiring diagrams, component locations, and testing procedures.
Safety First: Disconnect the negative battery terminal before working on any electrical components.
Wiring Diagrams: Understanding wiring diagrams is essential for troubleshooting electrical issues. Learn how to read them and trace circuits.
Proper Tools: Use the correct tools for the job. Don't force anything.
Document Everything: Take notes and pictures as you work. This will help you remember what you've done and retrace your steps if necessary.

Disclaimer: Working on your car can be dangerous. If you're not comfortable with any of these procedures, consult a qualified mechanic.

By systematically working through these troubleshooting steps, you should be able to identify and resolve the "key stuck in ignition" problem on your 2013 Subaru Impreza. Good luck!