C1224 Lamp Brake Warning Output Circuit Open
What does C1224 mean?
C1224 — Lamp Brake Warning Output Circuit Open. This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects lamp brake warning output circuit open. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of C1224
- Faulty wheel speed or chassis sensor
- Damaged wiring, connector, or corrosion in the sensor circuit
- Worn wheel bearing or damaged tone ring affecting the sensor gap
- Chipped or contaminated sensor reluctor wheel
- Failed ABS or chassis control module
How to fix C1224
These are general steps for this system. The exact cause depends on your vehicle — confirm with live scan data before replacing parts.
- Scan the chassis/ABS module for specific fault codes
- Inspect the affected sensor, wiring, and connector
- Read individual wheel speeds with an OBD-II scanner during a roll test
- Check the wheel bearing and reluctor ring condition
- Replace the failed sensor or component after circuit tests