C1421 Toyota Code - Open or Short in Master Cylinder Pressure Sensor

Code C1421 indicates an open or short circuit in the master cylinder pressure sensor circuit, which is part of the vehicle's braking system.

Common symptoms include the ABS warning light or brake warning light illuminating, reduced braking performance, and issues with the ABS system.

Possible causes include a faulty master cylinder pressure sensor, damaged wiring or connectors in the sensor circuit, or an issue with the ABS control module.

While the vehicle may still be drivable, it is not recommended as braking performance and ABS functionality could be compromised, posing a safety risk.

Start by visually inspecting the wiring and connectors for damage or corrosion, then use a multimeter to check for continuity in the circuit. A scan tool can also help test the ABS system and sensor functionality.

Repairs may include replacing the master cylinder pressure sensor, repairing or replacing damaged wiring or connectors, or reprogramming or replacing the ABS control module if necessary.

Repair costs vary depending on the issue, but replacing the master cylinder pressure sensor can cost between $200 and $400, excluding labor costs.

Not always. Wiring issues, connector problems, or faults in the ABS module can also trigger the C1421 code.

Clearing the code without addressing the underlying issue will not solve the problem. The code will likely return until the fault is properly repaired.

While C1421 is commonly associated with Toyota vehicles, other manufacturers may use different codes for similar issues. Always refer to the specific vehicle's service manual for accurate diagnostics.