Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble talking to the buttons on the steering wheel.
The vehicle's control module is not receiving expected communication signals from the multifunction steering wheel interface within a specified time.
The P155B code indicates a communication timeout between the vehicle's control module and the multifunction steering wheel interface. This can occur due to wiring issues, a faulty steering wheel control module, or a malfunctioning control unit.
• Steering wheel buttons not working
• Warning light on the dashboard
• Intermittent or no response from steering wheel controls
• Faulty steering wheel control module
• Damaged or corroded wiring/connectors
• Defective control unit or software glitch
OBD-II: On-Board Diagnostics, a standardized system in vehicles for self-diagnosing and reporting.
Multimeter: A tool used to measure electrical voltage, current, and resistance.
• Check for other related codes
• Inspect wiring and connectors for damage or corrosion
• Test the steering wheel control module functionality
• Repair or replace damaged wiring/connectors
• Replace the faulty steering wheel control module
• Update or reprogram the vehicle's control unit software
• OBD-II scanner
• Multimeter
• Screwdriver set
$100 - $500
Moderate
• BMW 3 Series
• Audi A4
• Mercedes-Benz C-Class
• Regularly inspect wiring for damage
• Ensure software updates are applied
• Avoid excessive moisture exposure in the vehicle interior
Communication Error
• Do not ignore the warning light; get it checked promptly
• Avoid using steering wheel controls until repaired
• Consult with a qualified technician for diagnosis
Check with your vehicle manufacturer for specific warranty coverage regarding electronic components.
This code has been more common in vehicles with advanced steering wheel controls, especially in models with integrated infotainment systems.
Moderate – While the car is still drivable, the lack of steering wheel controls can be inconvenient and potentially distracting.
Driving with malfunctioning controls can be distracting and may lead to accidents. Ensure repairs are conducted by a qualified professional.
• Vehicle on and stationary
• Steering wheel controls activated
The multifunction steering wheel interface is located within the steering wheel assembly.
Q: Can I still drive my car with this code?
A: Yes, but the steering wheel controls may not function properly, which can be inconvenient.
Q: Will this issue affect my car's performance?
A: No, it mainly affects the functionality of the steering wheel controls.
Pro · Four-system diagnostics
A handheld scanner aimed at engine, transmission, ABS, and airbag diagnostic work.
Chassis and ABS faults usually need a scanner that can read brake-system data directly.
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Universal · Torque wrench
Useful when reassembly torque matters for wheel, suspension, and under-hood fasteners.
Useful when wheel, hub, or suspension hardware needs correct reassembly torque.
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Universal · Drive-on ramps
Helpful for safer access underneath the vehicle during exhaust, EVAP, and underbody inspection work.
Helpful for safer access during underbody inspection work.
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