Pre-Collision Brake Actuator Circuit
2000-2012 Mitsubishi Eclipse 2.4L I4 🇨🇦
Description
Malfunction in the brake actuator used by the pre-collision system to automatically apply brakes.
Symptoms
- PCS warning light
- Automatic braking will not activate
- Pre-collision system disabled
Common Causes
- Brake actuator solenoid failure
- ABS modulator fault affecting PCS
- Wiring to actuator damaged
- Actuator mechanically stuck
Diagnostic Steps
- Test brake actuator solenoid resistance
- Command actuator with scan tool
- Check for ABS codes that disable PCS
- Inspect actuator wiring
- Test brake pressure response to PCS command
Repair Notes
Replace brake actuator or repair ABS modulator. PCS brake actuation may use the ABS hydraulic unit.
Related Codes
Other Chassis Codes
- C0021LF Wheel Speed Sensor Range/Performance
- C0022RF Wheel Speed Sensor Range/Performance
- C0023LR Wheel Speed Sensor Range/Performance
- C0024RR Wheel Speed Sensor Range/Performance
- C0025LF Wheel Speed Sensor Circuit Intermittent
- C0026RF Wheel Speed Sensor Circuit Intermittent
- C0027LR Wheel Speed Sensor Circuit Intermittent
- C0028RR Wheel Speed Sensor Circuit Intermittent
- C0035Left Front Wheel Speed Sensor Circuit
- C0036Left Front Wheel Speed Signal Erratic
C0421 on Other Vehicles
Mitsubishi Colt JP
2002-2012 1.3L I4 4A90
Mitsubishi Colt JP
2002-2012 1.5L I4 4A91
Mitsubishi Delica D:5
2019-2025 2.2L I4 Turbo Diesel 4N14
Mitsubishi Eclipse
2006-2012 2.4L I4
Mitsubishi Eclipse
2006-2012 3.8L V6
Mitsubishi Eclipse Cross
2018-2024 1.5L I4 Turbo
Mitsubishi Eclipse Cross
2018-2024 1.5L Turbo I4
Mitsubishi Eclipse Cross PHEV
2022-2024 2.4L I4 PHEV
Common Questions
What does code C0421 mean on a 2000-2012 Mitsubishi Eclipse?
C0421 stands for "Pre-Collision Brake Actuator Circuit". Malfunction in the brake actuator used by the pre-collision system to automatically apply brakes.
What are the symptoms of C0421 on a Mitsubishi Eclipse?
Common symptoms of C0421 include: PCS warning light, Automatic braking will not activate, Pre-collision system disabled.
What causes C0421 on a 2000-2012 Mitsubishi Eclipse?
Common causes of C0421 include: Brake actuator solenoid failure, ABS modulator fault affecting PCS, Wiring to actuator damaged, Actuator mechanically stuck.