What does it mean?
C1511 is a Chassis (ABS, traction control, steering) fault code. It indicates: Torque Sensor Circuit Malfunction .
Symptoms
- Power steering assist is lost or clearly reduced; the wheel becomes heavy
- Steering warning lamp on, sometimes with stability control lamps
- Assist cuts in and out while driving, often when turning at low speed
- Steering effort feels uneven between left and right
- Fault appears after heavy rain or a car wash where water intrusion is involved
Likely causes
- Internal torque sensor failure inside the steering column or rack assembly
- Water reaching the sensor after a windscreen, cowl or bulkhead leak
- Open or shorted wiring between the torque sensor and the steering control module
- Corroded, loose or partly unplugged connector at the steering gear or column
- Missing supply voltage or a poor ground at the sensor
- Torque sensor calibration not performed after replacing the column, rack or module
- Low system voltage from a weak battery, which electric steering is very sensitive to
How to fix it
- Test battery and charging voltage first; electric steering sets faults at low voltage
- Read torque sensor live data with the wheel at rest, where it should be near zero, and while applying effort in each direction
- Inspect the connector at the steering gear or column for water, corrosion and pushed back pins
- Measure supply voltage and ground at the sensor with the ignition on
- Test the signal wires for open circuits and shorts back to the module
- Perform the torque sensor calibration where the vehicle supports it
- Replace the sensor or the column or rack assembly as the design allows, then calibrate and road test