What Does B1334 Mean?
This code indicates the Body Control Module (BCM) has detected a short to ground condition in the decklid or rear door ajar switch circuit. The BCM continuously monitors the ajar switch wiring and when it detects voltage below expected threshold due to a short circuit path to ground, it sets this code. This prevents the BCM from accurately determining whether the decklid or rear door is actually open or closed.
Common Causes
45%
Damaged, chafed, or pinched wiring in the decklid/door harness causing direct contact with vehicle ground, typically in hinge area or body transition points
30%
Faulty decklid or rear door ajar switch with internal short to ground
15%
Corroded or water-damaged connector terminals creating ground path at ajar switch connector or BCM connector
10%
Failed Body Control Module with internal circuit fault on ajar input channel
Diagnostic Steps
1
Step 1: Perform visual inspection of decklid/rear door ajar switch and all associated wiring, especially at hinge points and body transition areas where wiring flexes. Look for chafed insulation, pinched wires, or signs of water intrusion at connectors.
2
Step 2: Disconnect the ajar switch connector and measure resistance from the signal wire terminal (BCM side of harness) to known good ground using a digital multimeter. Reading should be infinite (open circuit); any continuity indicates a short to ground in the wiring harness.
3
Step 3: If harness tests good, measure resistance across the ajar switch terminals with switch in both open and closed positions. Verify switch operates correctly and does not show continuity to ground on signal terminal when open.
4
Step 4: Check BCM connector terminals for corrosion, pushed-back pins, or moisture. Inspect connector seals and repair as needed. Clear codes and cycle the decklid/door multiple times while monitoring live data to verify proper switch operation.
5
Step 5: If all wiring and switch test good, suspect BCM internal fault. Verify BCM ground circuits are intact and have less than 0.5 ohms resistance to chassis ground before condemning BCM.
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a short to ground condition in the decklid or rear door ajar switch circuit. The BCM continuously monitors the ajar switch wiring and when it detects voltage below expected threshold due to a short circuit path to ground, it sets this co...
The most common cause of B1334 (Decklid Ajar Rear Door Circuit Short To Ground) is: Damaged, chafed, or pinched wiring in the decklid/door harness causing direct contact with vehicle ground, typically in hinge area or body transition points
Typical repair costs for B1334 range from $75 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive, but interior lights may remain on draining the battery, security system may not arm properly, and driver will not receive accurate warning if decklid/door is actually open. Repair at convenience but do not ignore potential battery drain.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1334 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Security System
Difficulty
Type
Manufacturer
Recommended Tools
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