STEERING Wheel Angle 1and 2 Circuit Failure
Your car's steering wheel angle sensor is sending conflicting or missing signals to the computer, like a compass needle spinning wildly instead of pointing in one direction. The system can't accurately measure how far you've turned the wheel, which is critical for stability control and safety systems.
The ECU monitors dual steering wheel angle sensors (redundant design for safety) that track steering input in degrees. It compares both sensors to verify agreement and checks for electrical continuity, voltage signals, and signal correlation within acceptable tolerances. A mismatch or open/short circuit triggers this fault.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Sensor voltage agreement | Within 5% correlation between sensor 1 and 2 | Deviation exceeds 5% or circuit open/short detected |
| Circuit resistance | 4.7-5.1 kΩ per sensor path | Open circuit (infinite Ω) or short to ground (<1 kΩ) |
Code C1277 is classified as a serious fault. If your check engine light is flashing — not just steady — pull over safely and do not continue driving. A flashing CEL indicates an active misfire or critical failure that can cause catalytic converter damage within minutes or permanent engine harm within miles. Contact a certified mechanic immediately. Do not attempt roadside repairs on high-severity codes unless you are trained to do so.
Once the fault is repaired, C1277 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.