C1939: Brake Pressure Switch Input Circuit Failure
CriticalChassisAnti-Lock Brakes
What does C1939 mean?
C1939 is a diagnostic trouble code indicating "Brake Pressure Switch Input Circuit Failure". This code relates to your vehicle's anti-lock brakes and should be diagnosed to determine the root cause. The severity level helps indicate how urgently this should be addressed.
Common causes
- Faulty anti-lock brakes component
- Wiring or connector issue in the related circuit
- Failed sensor providing incorrect readings
- Software/calibration issue requiring ECU update
- Related component causing secondary fault
What should you do?
This is a critical issue. Stop driving as soon as it is safe to do so and have the vehicle inspected immediately. Continuing to drive could cause further damage or pose a safety risk.
Get a diagnosis for YOUR car
Code C1939 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.