What does it mean?
C1247 is a Chassis (ABS, traction control, steering) fault code. It indicates: ABS System Hydraulic Pump Motor Circuit Failure . This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms
- ABS lamp on with the stability lamp and ABS unavailable
- No pump noise during the key-on or drive-away self test
- No pedal pulsation during an emergency stop, so the wheels lock instead
- Pump running continuously or long after the key is switched off on some faults
- Battery going flat if the pump keeps running
- Burning smell from the hydraulic unit area in severe cases
Likely causes
- Blown high current ABS pump fuse or fusible link
- Failed pump motor relay, or the relay driver inside the module
- Corroded, loose or burnt pump motor power and ground connections at the hydraulic unit
- Worn motor brushes or an open armature winding inside the pump motor
- Pump motor seized or drawing excessive current after long standing and corrosion
- Damaged pump feed cable, often where it passes the hydraulic unit bracket
- Poor module ground causing an incorrect motor circuit reading
How to fix it
- Check the high current pump fuse and the pump relay first, and inspect them for heat damage
- Command the pump with the scan tool activation test and listen, while measuring current draw if possible
- Measure voltage at the pump motor feed and ground while the pump is commanded, and voltage drop test both
- Inspect the hydraulic unit power and ground connections for corrosion and loose fixings
- Check the module connector terminals for burn marks and lost tension
- Rule out a stuck relay or a shorted control wire if the pump runs continuously
- Replace the pump motor or hydraulic unit assembly when the supply is proven good, then bleed and test the system