2019-2020 Cadillac CT6 Trunk Release Switch: Diagnosis and Replacement Guide

Common Symptoms of a Failing Trunk Release Switch

When the trunk release switch on a 2019-2020 Cadillac CT6 begins to fail, the symptoms are usually straightforward. You may experience one or more of the following issues:

• Switch is completely unresponsive: Pressing the button on the trunk does nothing. You won't hear a click from the latch, and the trunk will not open.
• Intermittent operation: The switch works sometimes but not others. You might need to press it multiple times, or hold it down, for the trunk to release. This often points to worn internal contacts or early-stage corrosion.
• Physical damage to the button: The rubber cover over the switch can become cracked, torn, or feel mushy. This damage allows water to get inside, which corrodes the switch's internal components and leads to failure.
🎬 Watch: How to diagnose a failed trunk release button

Diagnosing the Problem: Is It Really the Switch?

Before you buy a replacement switch, it's critical to perform a few simple checks. Often, the trunk release fails for reasons other than a bad switch. Follow these steps to avoid a misdiagnosis.

Step 1: Check the Valet Lockout Switch

This is the most common reason for a seemingly dead trunk release. The Cadillac CT6 is equipped with a valet mode that disables the trunk release for security. This feature is often activated by mistake.

Step 2: Test Other Release Methods

Try opening the trunk using the button on your key fob and the release button inside the car's cabin. If either of these methods works, but the exterior trunk button does not, it strongly suggests the exterior switch (part number 84450049) is the problem. If none of the buttons work, the issue is more likely with the trunk latch actuator, a fuse, or a wiring problem.

Step 3: Check for Broken Wires

A less common but possible issue is a broken wire in the wiring harness that runs from the car's body to the trunk lid. This harness flexes every time the trunk is opened and closed, and over time, a wire can break inside its insulation. This usually requires removing the trunk lid liner to inspect the harness near the hinge area.

Buying a Used 2019-2020 CT6 Trunk Release Switch

A used OEM trunk release switch is a smart, cost-effective choice for this repair. The part is simple, and a good-condition used unit will perform identically to a new one. Here’s what to look for:

• Verify the Part Number: Ensure the part is OEM number 84450049. While switches from other GM vehicles may look similar, only the correct part number guarantees perfect fitment and function.
• Inspect the Rubber Pad: This is the most critical inspection point. Do not buy a switch with any visible cracks, tears, or deterioration in the rubber button cover. A compromised cover is a sign that water has likely entered and damaged the internal electronics.
• Check the Electrical Connector: Look at the pins inside the connector port. They should be clean and shiny. Avoid any switch that shows signs of green or white corrosion, as this indicates water damage.
• Test the 'Click': The button should have a firm, tactile click when pressed. If it feels mushy, sticky, or doesn't spring back immediately, it may be failing internally.

Cost of a Replacement Trunk Release Switch (Part #84450049)

Note: Prices are estimates as of mid-2026 and can vary based on supplier and location. Shop labor is based on a 0.5-1.0 hour minimum charge.

Replacement Guide (DIY Difficulty: 1/5)

Replacing the trunk release switch is a very easy DIY job that requires basic tools and about 15-30 minutes.

1. Open the Trunk: Use your key fob, interior release, or manual key to open the trunk.
2. Remove the Trunk Lid Liner: The liner on the inside of the trunk lid is held in by a series of plastic push-clips. Use a trim removal tool or a flathead screwdriver to carefully pry the center of each clip out and then remove the clip. Once all clips are removed, the liner will come off.
3. Disconnect the Switch: Locate the back of the trunk release switch. Press the tab on the electrical connector and pull it away from the switch to disconnect it.
4. Remove the Old Switch: The switch is held in place by plastic tabs. Squeeze these tabs together while pushing the switch outward to release it from the trunk lid.
5. Install the New Switch: Push the new switch into the mounting hole from the outside until it clicks securely into place.
6. Reconnect and Test: Plug the electrical connector into the new switch. Before reinstalling the liner, test the new switch, the key fob, and the interior release button to ensure everything works correctly.
7. Reinstall the Trunk Lid Liner: Secure the liner back onto the trunk lid with the plastic clips.

Known Issues, Recalls, and Service Bulletins

As of mid-2026, there are no specific recalls or Technical Service Bulletins (TSBs) from GM or the NHTSA that directly address the failure of the trunk release switch on the 2019-2020 Cadillac CT6. The most widely reported issue is failure due to normal wear and water intrusion. Several recalls exist for the 2019-2020 CT6 for issues related to the transmission, turn signals, and TPMS, but none are related to the trunk latching or release system.

Frequently Asked Questions (FAQ)