C0421high severityChassis
Pre-Collision Brake Actuator Circuit
on 2015 Jeep Cherokee 3.2L V6 · AWD
What this code means
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.
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