A trunk that will not lock or unlock from the fob, button, or interior release is almost always a worn lock actuator. The trunk uses the same kind of small motor as the doors and it fails the same way. Here is the ranked list.
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A small motor pulls the latch open. After thousands of cycles the motor stalls. You hear a faint click or nothing. Solenoid-style actuators are usually a sealed unit replacement. Cost: $120 - $350. DIY: Medium. Severity: Low.
Get a Free AI Diagnosis →The dash-mounted or driver-door release switch wears out. Try every release method (fob, dash, inside-trunk emergency). The dead one is the switch. Cost: $20 - $120. DIY: Easy. Severity: Low.
Get a Free AI Diagnosis →A fading fob battery loses range to the trunk antenna first because trunk antennas often have less sensitivity than the door ones. Replace the CR2032 in the fob and retest. Cost: $5 - $10. DIY: Easy. Severity: Low.
Get a Free AI Diagnosis →Some cars share the trunk circuit with interior lights or the license plate light. A blown fuse can kill the release while other accessories still work. Cost: $2 - $10. DIY: Easy. Severity: Low.
Get a Free AI Diagnosis →Wires that cross from the body into the trunk lid flex with every open and close. After 100,000+ cycles a wire cracks. Lock, light, and rear-window defroster on the trunk lid all die together. Cost: $150 - $400. DIY: Hard. Severity: Low.
Get a Free AI Diagnosis →Work through these in order. Stop as soon as you find the cause - you usually do not need all four.
Use the fob, the dash button, and the inside-trunk emergency pull cord. Note which work. If only one is dead, the switch on that path is the issue. If all are dead, it is the actuator, fuse, or wiring.
Pry the fob open and replace the CR2032 coin cell. Fob batteries are the cheapest fix on this list and account for a lot of "trunk dead" complaints.
Find the "TRUNK" or "DECKLID" fuse (usually 15-20A) in the under-dash panel. A blown fuse looks like a broken metal strip across the top. Replace with same amperage.
With the trunk open and trim removed, find the latch assembly and the actuator. Apply 12V across the actuator's two motor leads (try both polarities for lock and unlock). If it clicks open, the actuator is fine - look at wiring and switches. If silent, the actuator is dead.
If your scanner shows one of these B-codes (body) along with the symptom, run a free AI diagnosis to confirm.
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Fold the rear seats down and reach into the trunk from inside the car. Every modern trunk has a glow-in-the-dark emergency release cord inside on the back of the latch - pull it and the trunk pops open.
Most commonly a weak fob battery - the trunk antenna is usually less sensitive than the door ones. Replace the CR2032 first. Less commonly the trunk antenna itself has failed.
$120 - $350 installed. Parts are usually $60 - $180, labor is 30-90 minutes depending on the model.
The actuator is energizing but not strong enough to release the latch. Worn motor, dirt in the latch, or a bent release rod. Try a shot of penetrating oil first.
Yes. A weak battery can leave the actuator without enough current to fire. Charge the battery and retest before buying parts.
On most cars the inside emergency pull is wired to disarm the alarm. The outside emergency keyhole (if equipped) may or may not - check your owner's manual.