Why is my Subaru auto lock not working?

The key issue most owners notice is that the doors no longer lock automatically when you walk away, or they don’t lock at all. The most common causes are a dead or weak key fob battery, an auto-lock setting that’s been disabled or not configured, or a faulty door lock actuator. Start by checking the fob, then review the vehicle’s settings and the door locks themselves.

Subaru’s auto-lock system is designed to boost security and convenience, relying on a network of fobs, sensors, and actuators. When something goes wrong—whether electrical, mechanical, or software-related—the feature can fail or behave inconsistently. This report explores the typical causes and provides practical steps you can take, including model-specific notes, to diagnose and fix the problem.

Common causes of auto-lock failure

Before listing the most frequent reasons, note that many issues are user-serviceable and revolve around the fob, the system settings, or the door mechanisms. The following items are the usual culprits across Subaru models.

1. Dead or weak key fob battery or malfunctioning fob


2. Auto-lock feature disabled or not configured in the vehicle’s settings


3. Faulty door lock actuator in one or more doors


4. Blown fuse or power supply issue to the lock system


5. Damaged wiring or door harness near the hinges


6. Anti-theft system or immobilizer interfering with locking


7. Aftermarket alarm or remote start hardware causing conflicts

Many auto-lock problems stem from the simplest causes, such as a depleted fob battery or a setting that was toggled off. If you identify one of these issues, addressing it can restore function without extensive repair.

Diagnosis and fixes

Before beginning repairs, gather the owner’s manual and, if possible, a Subaru-compatible diagnostic tool. This list provides practical steps to isolate the fault and guide you toward a fix.

• Test the key fob with a fresh battery and verify the button response, range, and lock/unlock actions


• Check the vehicle’s settings: ensure Auto Lock or Walkaway Lock and related door-lock preferences are enabled in the instrument cluster or settings menu (model-dependent)


• Listen for the lock motor when locking from the fob or interior switch; inspect doors for slow, sticky, or non-responsive actuators


• Inspect fuses related to power door locks (often labeled PDL or similar); replace any blown fuses and check for corrosion or loose connections


• Examine the wiring harness inside the doors, especially near the hinges, for wear, damage, or disconnections


• If available, retrieve fault codes with a Subaru-compatible scanner; BCM or module faults may appear as specific codes


• If the issue persists across multiple doors or is intermittent, consult a dealership or qualified automotive technician for a deeper diagnostic

Fixing the issue often requires replacing a faulty actuator or repairing a damaged door harness, especially on older Subarus with higher door-wiring wear. In many cases, re-enabling a disabled setting or replacing a battery is enough to restore function.

Model-specific notes

Subaru model years and trims differ in how auto-lock features are configured and accessed. Some newer models offer advanced keyless settings inside the vehicle’s menu, while older ones rely on simpler “auto lock” behavior that may be enabled when you close the door or walk away with the fob. If you’re unsure, consult your owner's manual or a local Subaru service center for model-specific instructions.

Safety and warranty considerations

If the auto-lock problem affects more than one door, or you notice warning lights, abnormal sounds, or persistent codes, contact a Subaru dealer or authorized automotive locksmith. Many issues may be covered under warranty or service bulletins, and a dealer can verify software updates or recalls relevant to your vehicle.

Summary

In most cases, Subaru auto-lock failure stems from a dead key fob battery, a disabled or misconfigured auto-lock setting, or a faulty door lock actuator. Start with simple checks—replace the fob battery, verify settings, and inspect the door locks and fuses—and proceed to more involved diagnostics if needed. Keeping a note of when and where the problem occurs can help speed up a professional diagnosis if required.

Why is my Subaru lock not working?

If your Subaru won't lock, first check the key fob battery and replace it if it's dead or weak. If that doesn't work, inspect the fuse box for a blown fuse, as this can affect all power locks. If only one door won't lock, the issue is likely the door lock actuator for that specific door. Other potential causes include damaged wiring or a physical obstruction in the lock mechanism. 
This video demonstrates how to program the key fob, which might solve the issue if the battery is not the problem: 54sMotorCarNutYouTube · Nov 9, 2023
Troubleshooting steps

• Check the key fob: A low or dead battery is a common culprit. Replace the battery in the fob. 
• Inspect the fuse box: Locate the fuse box (check your owner's manual for the location) and look for any blown fuses related to the door locks. Replace any that are blown. 
• Examine for obstructions: Check the door lock mechanism for any physical obstructions, such as debris, and clear them. 
• Lubricate the locks: Use a silicone-based lubricant on the door's lock and latch assemblies to smooth out any sticky parts. 
• Address a single door issue: If only one door won't lock, it's likely an issue with that specific door's lock actuator or its wiring. You may need to have the actuator replaced, which often involves removing the inner door panel. 
• Check wiring: Look for any signs of damage, fraying, or corrosion in the wiring that connects to the door lock mechanisms. 
• Reset the key fob: If you replace the battery but the fob still doesn't work, you may need to resync it with the car. Consult your owner's manual for instructions on how to do this. 

This video explains how to reprogram the key fob, which might solve the issue if the battery is not the problem: 48sSecurityFirstCorpYouTube · Oct 8, 2024

Why is my automatic key lock not working?

Low or Dead Batteries — The #1 reason automatic or smart locks stop working. If there's no light or sound, the batteries probably need replacing. Misaligned Door — If the door and frame don't match up correctly, the lock's bolt might not slide in the way it should.

Why is my car auto locking not working?

Possible reasons why your car door isn't locking include problems with the key fob, such as a dead battery and a stuck button. If the key fob is working, the door lock might not be working due to door lock actuator issues, a blown fuse, or faulty wiring.

Why doesn't my Subaru auto lock?

A weak or dead battery in the key fob can lead to erratic lock behavior. Replace the battery and see if the issue persists. Sometimes, foreign objects or debris can obstruct the locking mechanism. Inspect the door jambs and locks for any visible obstructions.