A wheel speed sensor of the wrong part number or type installed at the left rear position; Aftermarket sensor with incorrect internal resistance or signal output that does not match the module's expected profile; Sensor from a different model year or trim level that physically fits but electrically differs; Damaged or corroded sensor connector causing the module to read an unexpected electrical signature; Wiring harness repair or splice that alters the sensor circuit's resistance or shielding; Contaminated or damaged sensor tip affecting the magnetic signal, leading the module to misidentify the component; Incorrect sensor installed during a previous repair, such as a front sensor fitted to the rear position

DTC codes / C05xx · Brakes, steering and suspension / C0557

C0557Left Rear Wheel Speed Sensor A Incorrect Component Installed

C0557 indicates that the anti-lock brake system (ABS) control module has detected an incorrect component installed at the left rear wheel speed sensor position, meaning the sensor's electrical signature does not match what the module expects for that corner. The module compares the sensor's signal characteristics against stored parameters and flags this code when the installed part is not the correct type for the left rear location.

SystemChassis

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaBrakes, steering and suspension

Symptoms you may notice

Anti-lock brake system (ABS) warning light illuminated on the dashboard
Traction control or stability control warning light also on, since these systems share wheel speed data
ABS and traction control systems disabled, though normal base braking remains functional
Often no symptoms besides the warning light, with the vehicle driving normally
In some cases, a slight pulsation or unusual brake pedal feel during low-speed stops if the module misinterprets the signal

Common causes, most likely first

A wheel speed sensor of the wrong part number or type installed at the left rear position
Aftermarket sensor with incorrect internal resistance or signal output that does not match the module's expected profile
Sensor from a different model year or trim level that physically fits but electrically differs
Damaged or corroded sensor connector causing the module to read an unexpected electrical signature
Wiring harness repair or splice that alters the sensor circuit's resistance or shielding
Contaminated or damaged sensor tip affecting the magnetic signal, leading the module to misidentify the component
Incorrect sensor installed during a previous repair, such as a front sensor fitted to the rear position

How to diagnose and fix it

Verify the exact part number on the currently installed left rear wheel speed sensor against the manufacturer's catalog for the vehicle's VIN
Inspect the sensor connector and wiring for corrosion, damage, or poor repairs that could alter the electrical signature
Clear the code and recheck after a short drive to confirm it returns, ruling out a stored fault from a previous repair
Measure the sensor's resistance and compare it to the specification for the left rear position, not just a generic value
If the sensor is incorrect, replace it with the proper OEM or equivalent part for the left rear location
After replacement, clear codes and perform a road test to verify the ABS and traction control systems operate correctly
If the code persists with the correct sensor, diagnose the ABS module or wiring harness for faults that could mimic an incorrect component

Why the correct sensor still sets C0557

A sensor that looks identical and plugs in may have a different internal resistance or signal pattern, so the ABS module flags it as an incorrect component even though it fits physically.
This code often appears after a brake or suspension repair where a sensor was replaced with a cheaper aftermarket unit that does not meet the original equipment specifications.
Corroded terminals or a poor splice in the sensor wiring can change the circuit's electrical characteristics enough for the module to misinterpret the sensor as the wrong part.
The code does not always mean the sensor itself is wrong; a damaged tone ring or air gap issue can distort the signal so the module cannot recognize the expected component.
Some vehicles require a relearn or calibration procedure after sensor replacement, and skipping it can leave a stored incorrect-component code even with the right part installed.

Can I keep driving with C0557?

The vehicle remains safe to drive under normal braking because the base hydraulic system is unaffected, but ABS and traction control are disabled, so avoid slippery conditions and hard braking where those systems would normally intervene. Have the fault diagnosed promptly to restore full safety system function.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.