C1278 – OBD-II DTC

OBD-II DTC C1278 – STEERING Wheel Angle 1and 2 Signal Faulted

DTC C1278 meaning

DTC C1278 refers to a fault in the Steering Wheel Angle Sensor, specifically indicating that the signals from Steering Wheel Angle 1 and 2 are not functioning correctly. This diagnostic trouble code is part of the On-Board Diagnostics II (OBD-II) system and is crucial for the proper functioning of various vehicle systems, including stability control and traction control. The steering wheel angle sensors provide information about the position of the steering wheel, which is essential for the vehicle’s electronic control units to make informed decisions regarding handling and stability.

DTC C1278 symptoms

Common symptoms associated with DTC C1278 may include:

• Illumination of the check engine light or warning lights related to steering or stability control.
• Unresponsive or erratic steering behavior.
• Difficulty in maintaining vehicle stability during turns.
• Activation of traction control or stability control systems without cause.
• Inconsistent readings from the steering wheel angle display on the dashboard.

DTC C1278 causes

Several factors can lead to the occurrence of DTC C1278, including:

• Faulty steering wheel angle sensors.
• Wiring issues, such as damaged or corroded connectors.
• Calibration errors after steering component replacement.
• Software glitches in the vehicle’s control modules.
• Mechanical issues affecting the steering system.

DTC C1278 seriousness

The seriousness of DTC C1278 can vary based on the vehicle’s design and the specific symptoms present. However, it is generally considered a moderate to high priority issue because:

• It can affect the vehicle’s handling and stability, posing a safety risk.
• It may lead to further damage to the steering system if not addressed.
• It can trigger other warning lights and codes, complicating diagnostics.

How to diagnose DTC C1278

To diagnose DTC C1278, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC C1278.
2. Inspect the steering wheel angle sensors and their wiring for visible damage or corrosion.
3. Check for any related DTCs that may provide additional context.
4. Test the voltage and signal output from the steering wheel angle sensors.
5. Verify the calibration of the steering wheel angle sensors using a diagnostic tool.

How to fix DTC C1278 step-by-step instructions

To fix DTC C1278, follow these steps:

1. Clear the DTC using an OBD-II scanner.
2. Inspect and repair any damaged wiring or connectors related to the steering wheel angle sensors.
3. If necessary, replace faulty steering wheel angle sensors.
4. Recalibrate the steering wheel angle sensors using a diagnostic tool.
5. Test drive the vehicle to ensure the issue is resolved and no new codes appear.

How to erase DTC C1278

To erase DTC C1278, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the DTC menu on the scanner.
4. Select the option to clear or erase the trouble codes.
5. Confirm the action and wait for the scanner to indicate that the codes have been cleared.
6. Disconnect the scanner and perform a test drive to ensure the code does not return.

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