B3889 Code - Trailer Brake Lamps
Quick Answer
The B3889 diagnostic trouble code (DTC) specifically relates to an issue with the trailer brake lamps on the vehicle. Common causes include Faulty trailer brake lamp bulbs, Wiring issues such as frayed or damaged wires, Corrosion in connectors related to the trailer brake lamp circuit. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- B3889 indicates Trailer Brake Lamps.
- Common causes
- Common causes include Faulty trailer brake lamp bulbs, Wiring issues such as frayed or damaged wires, Corrosion in connectors related to the trailer brake lamp circuit.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code B3889 Description
The B3889 diagnostic trouble code (DTC) specifically relates to an issue with the trailer brake lamps on the vehicle. When this code is triggered, it indicates that there is a malfunction or fault in the trailer brake lamp circuit. This could be due to a variety of reasons, such as a faulty lamp, wiring issue, or a problem with the brake lamp control module.
Common Causes of B3889
- Faulty trailer brake lamp bulbs.
- Wiring issues such as frayed or damaged wires.
- Corrosion in connectors related to the trailer brake lamp circuit.
- Malfunctioning brake lamp control module.
- Issues with the vehicle's electrical system.
Symptoms of B3889
- Trailer brake lamps not illuminating when the vehicle is braking.
- Dashboard warning light indicating a fault with the trailer brake lamps.
- Flickering or dim trailer brake lamps.
- Inconsistent operation of the trailer brake lamps.
How to Fix B3889
- Begin by visually inspecting the trailer brake lamp bulbs for any signs of damage or wear. Replace any faulty bulbs.
- Check the wiring and connectors in the trailer brake lamp circuit for any damage or corrosion. Repair or replace as needed.
- Test the brake lamp control module to determine if it is functioning correctly. Replace if necessary.
- Clear the DTC from the vehicle's onboard computer using a diagnostic scanner.
- Test the trailer brake lamps to ensure they are now functioning properly.
Cost to Fix B3889
The typical repair costs for addressing the B3889 code related to trailer brake lamps can vary depending on the specific cause of the issue. On average, the cost of replacing trailer brake lamp bulbs can range from $10 to $30 per bulb. If the issue is related to wiring or the control module, the repair costs could be higher, potentially ranging from $100 to $300 or more. Labor costs for this type of repair can vary between $80 and $150 per hour, with total costs likely falling between $150 and $500. It is advisable to consult with a professional mechanic to get an accurate estimate based on the specific circumstances of the vehicle.
Tech Notes for B3889
B3889 04 Trailer Brake Lamps Circuit Open
Need more information about the B3889 code?
Need more information on how to fix the B3889 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the B3889 code diagnosed by a professional: Find a repair shop in your area
Code B3889 Information for Specific Makes
- B3889 Buick — Trailer Brake Lamps
- B3889 Cadillac — Trailer Brake Lamps
- B3889 Chevrolet — Trailer Brake Lamps
- B3889 GMC — Trailer Brake Lamps
Frequently Asked Questions about B3889 Code
No Frequently Asked Questions about B3889 Code found.
Discuss the causes and fixes for B3889 OBDII Code
Code B3889 comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.