When your 2021 Chevrolet Malibu displays a trunk open warning even though the trunk is firmly closed, you're dealing with a sensor or switch problem. This false alarm can drain your battery if the trunk light stays on, and it's an ongoing annoyance seeing the warning.
How Trunk Status is Detected
The Malibu uses a trunk ajar switch, typically integrated into the trunk latch assembly, to detect whether the trunk is open or closed. When the trunk closes, a plunger or pin switch makes contact, signaling "closed" to the body control module. When this signal is incorrect, you get a false trunk open warning.
Causes of False Trunk Open Warning
The false warning typically stems from: a faulty trunk ajar switch, misaligned trunk latch or striker, damaged wiring to the trunk switch, a trunk that's not fully latching closed, corrosion on switch contacts, or a bent trunk lid that prevents proper switch engagement.
Symptoms to Note
Beyond the warning message: Does the trunk interior light stay on? (Confirms system thinks trunk is open) Does the warning come and go over bumps? (Loose connection or intermittent switch) Is the trunk actually not latching fully? (Alignment issue) Was this after trunk damage or repair?
Diagnostic Process
Verify the trunk latches fully by pressing down firmly. Inspect the trunk latch and striker for misalignment. Check the trunk ajar switch for proper operation by manually depressing it. Look for damaged wiring in the trunk hinge area. Monitor the switch input using a GM scan tool.
Repair Solutions
Trunk latch adjustment may resolve alignment issues. Trunk ajar switch replacement addresses failed switches. Wiring repair for damaged harnesses. Striker adjustment brings the lid into proper position. In some cases, the entire latch assembly requires replacement to resolve integrated switch failures.