What does it mean?
C1140 is a Chassis (ABS, traction control, steering) fault code. It indicates: ABS Actuator Relay System . 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 and stability control warning lamps on
- No relay click or pump noise when the ignition is switched on
- ABS never activates during emergency braking
- Traction control and stability assistance disabled
- Fault can be intermittent, often worse in damp or cold conditions
- Warning lamps come on after driving through standing water
Likely causes
- Failed relay inside or beside the hydraulic actuator assembly
- Corroded, burnt or loose terminals in the relay socket or actuator connector
- Blown main fuse or fusible link on the actuator supply
- Weak battery or charging fault so the relay does not pull in reliably
- Poor ground for the actuator, a rusted stud or a damaged ground strap
- Water ingress into the actuator connector after washing or flooding
- Failed relay control or feedback stage inside the ABS control module
How to fix it
- Check the main fuses and fusible links for the ABS actuator
- Test battery condition and charging voltage before condemning the relay
- Inspect the relay socket and actuator connector for corrosion, heat marks and moisture
- Substitute a known good relay where it is a plug-in type, or bench test the coil and contacts
- Perform voltage drop tests on the actuator feed and ground while the relay is commanded
- Repair the wiring, clean and tighten the ground point, and dry and seal the connector
- Replace the actuator assembly if the relay is integral and proven faulty, then code and bleed the brakes