What does it mean?
C1255 is a Chassis (ABS, traction control, steering) fault code. It indicates: Electronic Control Unit Performance .
Symptoms
- ABS and stability control warning lamps stay on after every start
- ABS, traction and stability functions disabled while normal braking remains
- The module answers the scan tool intermittently or not at all
- Wheel speed based data such as the speedometer reading may be missing on some vehicles
- The code returns immediately after clearing
Likely causes
- Internal fault inside the chassis/ABS control module (memory, self-test or output driver failure)
- Low or unstable supply voltage from a weak battery or a failing charging system
- Loose, corroded or high-resistance module power feed and ground points
- Water intrusion and corrosion inside the module connector
- Corrupted or mismatched module software after an interrupted programming session
- Voltage spikes from jump starting or from welding carried out on the vehicle
- A shorted actuator on a module output overloading an internal driver
How to fix it
- Test the battery and the charging system first; correct any low voltage before condemning the module
- Check module power feeds, fuses and ground points with a voltage drop test
- Unplug and inspect the module connector for bent pins, moisture and green corrosion, then reseat it
- Scan every module for communication faults so a network problem is ruled out
- Check whether updated control module software is released for the application and reprogram if so
- Confirm that no valve solenoid or pump motor is shorted and loading an internal driver
- Replace the control module last, then program and calibrate it as required