C0657 indicates that the ABS/ESC control module has detected that the left front wheel speed sensor B is not the correct component for the vehicle. This usually means the wrong sensor was installed, the sensor is faulty, or its wiring/connector is damaged, causing the module to reject the signal.
The sensor part number or type does not match the vehicle’s specification, causing the control module to reject it as an invalid component.
The sensor itself has failed internally (e.g., damaged coil, cracked tone ring, or internal short/open) and does not produce a valid signal.
Corrosion, broken wires, loose pins, or shorted circuits in the harness can prevent the module from receiving a proper signal, triggering the incorrect‑component code.
Less commonly, the module’s firmware may be corrupted or incorrectly calibrated, causing it to misinterpret a good sensor signal as an incorrect component.
Very rare; the powertrain control module would only be considered if all sensor, wiring, and ABS module checks pass and the code persists.
No. The PCM/ECM is rarely the cause of C0657; the issue is almost always the wheel speed sensor, its wiring, or the ABS module. Replacing the PCM is not a recommended first step.
You can still drive, but the ABS and stability control systems may be disabled or impaired. Anti‑lock braking assistance will not function, so drive cautiously, especially in slippery conditions.
Remove the sensor and compare its part number or physical specifications to the vehicle’s service information. An incorrect part will trigger C0657 even if it appears to work.
Clear the DTC with a scan tool and verify that the code does not return. Some vehicles may require a sensor re‑learn or ABS module calibration after replacement.