What does it mean?
C1428 is a Chassis (ABS, traction control, steering) fault code. It indicates: Motor Circuit Malfunction .
Symptoms
- ABS and traction/stability lamps on, sometimes with the brake warning lamp
- No pump buzz during the key-on self test, which is normally audible
- No ABS pulsation and possible wheel lock during hard braking on a slippery surface
- Traction control, hill hold and trailer stability functions disabled
- Occasionally the pump runs continuously or keeps running after the key is off
Likely causes
- Failed pump motor relay, or burnt relay contacts inside the ABS unit
- Blown high current ABS fuse in the engine bay fuse box
- Loose, corroded or heat damaged terminals in the ABS module power connector
- High resistance or an open in the heavy motor feed or the motor ground strap
- Worn pump motor brushes or a seized pump motor that will not turn
- Weak battery, poor main ground or a charging fault causing low voltage during the self test
- Internal driver failure inside the hydraulic control unit
How to fix it
- Test the battery and charging system, then inspect and clean the main engine and body grounds
- Check the high current ABS fuses and the pump motor relay
- Command the pump with a bidirectional scan tool and listen for it running
- Measure voltage at the module power feed while the pump is commanded and perform a voltage drop test on the ground
- Inspect the ABS connector pins for corrosion, spread terminals and heat marks
- Check for other codes that indicate low system voltage before condemning the unit
- If supply and ground are good and the motor still does not run, replace the pump motor or the hydraulic control unit assembly, then bleed the system as required