What Does B1426 Mean?
This code indicates that the Body Control Module (BCM) has detected an abnormal voltage condition in the seat belt warning lamp circuit, specifically a short circuit to battery voltage. The seat belt reminder lamp is receiving constant power when it should be controlled by the BCM, causing the lamp to illuminate improperly or stay on continuously. This is a body control system fault affecting the seat belt warning indicator functionality.
Common Causes
45%
Damaged or chafed wiring in the seat belt lamp circuit creating a short to battery positive voltage
30%
Faulty instrument cluster with internal short circuit in seat belt lamp driver
15%
Corroded or damaged connector pins at BCM or instrument cluster creating cross-circuit short
10%
Failed Body Control Module with shorted output driver for seat belt lamp circuit
Diagnostic Steps
1
Step 1: Perform visual inspection of the instrument cluster wiring harness and BCM harness for obvious damage, chafing, melted insulation, or pinched wires, especially near sharp metal edges and routing points
2
Step 2: Using a digital multimeter, disconnect the instrument cluster connector and measure voltage on the seat belt lamp circuit wire with ignition on - should read 0V if controlled by BCM; battery voltage confirms short to power
3
Step 3: Disconnect the BCM connector and recheck voltage on the seat belt lamp wire - if voltage disappears, BCM is faulty; if voltage remains, short exists in harness between BCM and cluster
4
Step 4: Perform continuity test between the seat belt lamp circuit wire and known battery positive circuits with all connectors disconnected to isolate exact location of short circuit
5
Step 5: Inspect all connector terminals for corrosion, bent pins, or moisture intrusion that could cause cross-circuit shorting between adjacent pins
6
Step 6: After repairs, reconnect all components, clear codes, cycle ignition and seat belt multiple times, and verify seat belt lamp functions correctly and code does not return
Estimated Repair Cost
$100 - $650
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) has detected an abnormal voltage condition in the seat belt warning lamp circuit, specifically a short circuit to battery voltage. The seat belt reminder lamp is receiving constant power when it should be controlled by the BCM, causing the lamp ...
The most common cause of B1426 (Lamp Seat Belt Circuit Short To Battery) is: Damaged or chafed wiring in the seat belt lamp circuit creating a short to battery positive voltage
Typical repair costs for B1426 range from $100 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this only affects the seat belt warning lamp indicator, not the actual seat belt functionality. However, you will not receive proper seat belt reminders, which is a safety concern for ensuring all occupants are buckled. Repair within a reasonable timeframe to restore proper warning system operation.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1426 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Warning Light System
Difficulty
Type
Manufacturer
Recommended Tools
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