B1334
Decklid Ajar Rear Door Circuit Short To Ground
Body Chassis/Safety Decklid sensor circuit 🟢 Low — Fix at next service
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What This Actually Means
In plain language — no jargon

The decklid (trunk) ajar sensor circuit is shorted to ground, meaning the electrical signal wire is touching a metal part and creating a false low signal. It's like a light switch that's stuck in the "on" position because someone shorted the wires together.

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Symptoms You May Notice
3 known symptoms for this code
Decklid ajar warning light stays on continuously
Vehicle may not lock or unlock decklid properly
Dashboard message displays trunk/decklid open alert when actually closed
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors the decklid ajar sensor's voltage signal, which should be high (near 5V) when closed and low (near 0V) when open. A short to ground forces the signal to remain near 0V continuously, triggering a fault code. The ECU compares this signal against expected thresholds for the vehicle's current state.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Decklid Sensor Voltage 4.5-5.0V when closed, 0.2-0.5V when open Stuck below 0.5V in closed position
Signal Circuit Resistance 100kΩ+ to ground when functioning Less than 10Ω to ground (short circuit)
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Decklid ajar sensor connector
Inspect and reseat the connector at the decklid and door jamb for corrosion or loose pins.
2
Decklid wiring harness
Check the wire loom along the decklid hinge for pinched, abraded, or cut insulation causing a ground short.
3
Decklid ajar switch/sensor
Replace the faulty sensor if continuity testing confirms internal short to ground.