Fault code B1300 – a step-by-step guide to diagnosing and fixing it

Error code B1300 is displayed and the check engine light is on - what does this mean?

The DTC B1300 is a body control trouble code that is recognized by the OBD/EOBD system and indicates a problem with the vehicle lighting or the lighting control module. This trouble code mainly affects the headlight, tail light or interior lighting systems and can have different specific meanings for different manufacturers.

What causes can this error code have?

• Defective bulbs or LED modules
• Damaged cable connections in the lighting system
• Loose or corroded plug connections
• Defective lighting control module (BCM)
• Blown fuses in the lighting circuit
• Faulty light switches or dimmer switches
• Short circuit in the wiring
• Defective relays in the lighting system
• Problems with the vehicle ground

What symptoms occur in parallel with fault code B1300?

• Lighting failures: Headlights, tail lights or interior lighting do not work properly
• Flickering lights: Irregular illumination or dimming of the lights
• Warning lights: Indicator lights for faulty bulbs come on in the dashboard
• Electrical faults: Other electrical systems may be affected
• Safety issues: Reduced visibility in darkness or poor weather conditions

How to fix the problem of fault code B1300?

• Fixing fault code B1300 requires a systematic check of the lighting system.
• Replace bulbs and LED modules: Identify all defective bulbs and replace them with new, compatible spare parts
• Check and replace fuses: Locate and test lighting fuses in the fuse box and replace if necessary
• Repair cable connections: Repair or completely replace damaged or corroded cables in the lighting system
• Clean plug connections: Disconnect, clean and firmly reconnect all plugs in the lighting system
• Replace lighting control module: Replace defective BCM with a new or refurbished module and have it programmed
• Replace light switch: Replace faulty main light switch or dimmer switch with a new component
• Check earth connections: Check all ground connections of the lighting system for tightness and freedom from corrosion