2012-2020 Chevrolet Sonic Trunk Latch: Fixing a Stuck or Randomly Opening Trunk

Common Symptoms of a Failing Sonic Trunk Latch

When the trunk latch on a Chevrolet Sonic begins to fail, it can manifest in several ways. Because the latch is both mechanical and electrical, problems can be intermittent at first, making diagnosis tricky. Here are the most common signs that your latch needs attention.

• Trunk or Hatch Won't Open: You may hear a click from the latch, but it doesn't release, or you may hear no sound at all. This can be caused by a failed actuator motor, a broken mechanical component inside the latch, or an electrical issue like a blown fuse or bad switch.
• Trunk or Hatch Won't Latch Closed: The trunk lid or hatch bounces back up when you try to close it. This often happens when the latch mechanism gets stuck in the "closed" position and cannot engage with the striker on the car's body.
• "Trunk Ajar" Warning Light Stays On: The dashboard displays a warning that the trunk is open even when it is securely shut. This points to a failure of the internal microswitch that is supposed to detect the latch's position.
• Trunk Opens By Itself: The trunk may unlatch randomly while the car is parked, sometimes without the key fob button being pressed. This is a known issue, particularly on early sedans, and can also be caused by water getting into the exterior release switch.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

While there are no major safety recalls for the trunk latch on the 2012-2020 Sonic, Chevrolet has issued Technical Service Bulletins (TSBs) to address specific, common problems.

TSB PI0924A: Trunk Opens By Itself (2012-2014 Sonic Sedan)

Owners of early model sedans may experience the trunk opening unexpectedly while the vehicle is parked. GM identified that this could be caused by the key fob's trunk release button being pressed accidentally in a pocket or purse. To fix this, GM released a special procedure.

• The Problem: The trunk release relay is integrated into a circuit board and cannot be easily replaced.
• The Fix: Dealers are instructed to install an external "Two Shot Relay" (GM Part Number 19119267). After this modification, the trunk release button (on the fob, interior, or exterior) must be pressed twice within three seconds to open the trunk. This prevents accidental openings.

TSB PI0945: Hatchback Liftgate Won't Open (2012-2013 Sonic Hatchback)

Some owners of early hatchbacks reported that the liftgate would not open using the key fob or the exterior touchpad. This issue has two potential causes.

• User Error: The system requires the user to press the "Unlock" button on the key fob twice to enable the exterior touchpad. Many users were only pressing it once.
• BCM Software Anomaly: If the touchpad still doesn't work after pressing unlock twice, the Body Control Module (BCM) may have a software glitch. The official fix is for a dealer to reprogram the BCM with an updated software calibration. DO NOT replace the BCM for this issue.

Diagnosing a Faulty Trunk Latch

Before spending money on parts, follow these simple diagnostic steps:

1. Check the Fuse: The first and easiest step is to check the fuse for the liftgate/trunk release. It is a 10-amp fuse located in the interior fuse panel (under the dashboard on the driver's side).
2. Try All Opening Methods: Attempt to open the trunk using the key fob, the interior release button (if equipped), and the exterior touchpad. If only one method fails, the problem is likely with that specific switch, not the latch itself.
3. Listen for the Actuator: Have someone press the release button while you listen at the trunk. If you hear a click or a whirring sound, the latch is receiving power, but the mechanical part is likely jammed or broken internally. If you hear nothing, the problem is likely electrical (fuse, wiring, switch, or the actuator motor itself).
4. Manual Release: If your trunk is stuck shut, you can open it manually from the inside. On hatchback models, there is a small round plug on the interior trim panel near the bottom of the hatch. Remove this plug and use a flathead screwdriver to turn the mechanism inside to release it. Sedans typically have a glow-in-the-dark emergency release handle.

Buying a Used 2012-2020 Sonic Trunk Latch: What to Check

A used OEM trunk latch from a reputable recycler is an excellent, cost-effective repair option. New aftermarket latches can have questionable electronics and fitment issues, while a used original part was designed for the vehicle. Here’s what to inspect before buying:

• Verify the Part Number: Ensure the part number matches your original or is a known compatible replacement. The primary OEM part number for the liftgate latch assembly is 13558646, which has replaced several previous numbers like 13583437 and 13577903.
• Inspect the Electrical Connector: Look closely at the pins inside the connector. Avoid any latch that shows signs of corrosion, like white or green powder. This indicates water intrusion, which is a common cause of electrical failure.
• Test the Mechanical Action: Use a screwdriver to gently push the U-shaped catch into the closed position. It should click securely. Then, simulate the release action by moving the small lever the actuator would push. The catch should spring open smoothly. If it feels gritty or sticks, the mechanism is worn.
• Check for Physical Damage: Inspect the plastic housing for any cracks or broken tabs, which could indicate it was removed forcefully or came from a vehicle in a major collision.

Cost to Replace a Chevrolet Sonic Trunk Latch

The cost can vary significantly depending on the part source and who performs the labor. The actuator motor can sometimes be purchased separately, but it is often simpler to replace the entire latch assembly.

Trunk Latch Replacement Guide (DIY)

Replacing the trunk latch is a beginner-friendly job that requires basic tools.

• Difficulty: 2/5
• Estimated Time: 30-45 minutes
• Tools Needed: Trim removal tool, socket set (likely 10mm), screwdriver.

Procedure:

1. Open the Trunk/Hatch: If it's stuck closed, use the manual release procedure described in the diagnosis section.
2. Remove the Interior Trim Panel: Use a trim removal tool to carefully pry off the large plastic panel on the inside of the trunk lid or hatch. It is held on by a series of hidden clips.
3. Disconnect Electrical Connector: Locate the wire harness going to the latch and disconnect the electrical connector. Press the small tab on the connector and pull it straight out.
4. Unbolt the Old Latch: The latch is typically held in place by two or three bolts. Use a socket wrench to remove them.
5. Install the New Latch: Position the new latch and hand-tighten the bolts. Connect the electrical connector.
6. Test Before Closing: Before reinstalling the trim panel, test the new latch. Use a screwdriver to close the latch mechanism, then use the key fob or release button to ensure it pops open correctly.
7. Final Assembly: Once you've confirmed it works, tighten the mounting bolts securely. Reinstall the interior trim panel by aligning the clips and pressing it firmly into place.

Frequently Asked Questions (FAQ)