Damaged or dirty left rear wheel speed sensor (commonly contaminated by debris or metal particles); Wiring harness damage (chafed, corroded, or broken wires) between the sensor and the ABS module; Failed left rear wheel speed sensor due to internal electrical fault or physical damage; Debris or corrosion on the sensor mounting surface or tone ring, causing an erratic signal; Damaged or excessively rusted tone ring (reluctor ring) on the left rear hub or axle; Poor electrical connection at the sensor connector or ABS module; Rarely, a fault within the ABS control module itself

DTC codes / C00xx · Brakes, steering and suspension / C0041

C0041Left Rear Wheel Speed Sensor Circuit Range/Performance

Q: What does code C0041 mean?

Left Rear Wheel Speed Sensor Circuit Range/Performance. C0041 indicates that the anti-lock brake system (ABS) module has detected an abnormal signal from the left rear wheel speed sensor circuit, where the signal is outside the expected range or performance criteria. The computer compares the left rear wheel speed to the other three wheels and sets this code when the signal is erratic, missing, or implausible during driving.

C0041 indicates that the anti-lock brake system (ABS) module has detected an abnormal signal from the left rear wheel speed sensor circuit, where the signal is outside the expected range or performance criteria. The computer compares the left rear wheel speed to the other three wheels and sets this code when the signal is erratic, missing, or implausible during driving.

SystemChassis

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaBrakes, steering and suspension

Symptoms you may notice

ABS warning light illuminated on the dashboard
Traction control or stability control warning light may also be on
Often no symptoms besides the warning light
ABS may deactivate, leading to conventional braking without anti-lock function
Possible intermittent or reduced operation of speedometer or cruise control if the sensor signal is used by other systems
In rare cases, a slight pulsation or drag felt during braking if the sensor sends erratic signals

Common causes, most likely first

Damaged or dirty left rear wheel speed sensor (commonly contaminated by debris or metal particles)
Wiring harness damage (chafed, corroded, or broken wires) between the sensor and the ABS module
Failed left rear wheel speed sensor due to internal electrical fault or physical damage
Debris or corrosion on the sensor mounting surface or tone ring, causing an erratic signal
Damaged or excessively rusted tone ring (reluctor ring) on the left rear hub or axle
Poor electrical connection at the sensor connector or ABS module
Rarely, a fault within the ABS control module itself

How to diagnose and fix it

Inspect the left rear wheel speed sensor and its wiring for visible damage, corrosion, or debris; clean the sensor and mounting area if contaminated
Check the tone ring for cracks, missing teeth, or excessive rust; replace if damaged
Measure the sensor's resistance and compare to the manufacturer's specification; replace the sensor if out of range
Perform a wiggle test on the wiring harness while monitoring sensor signal with a scan tool to detect intermittent faults
Check for continuity and short circuits in the wiring between the sensor and ABS module; repair any damaged wires
Clear the code and test-drive the vehicle to verify if the code returns; if it does, proceed to more advanced diagnostics
If all external components check out, diagnose the ABS module for internal faults, which may require replacement or reprogramming

Common misdiagnosis traps for C0041

A dirty or loosely mounted sensor is a frequent cause that is often overlooked; cleaning and reseating the sensor can resolve the issue without replacement.
The tone ring may appear intact but have micro-cracks or rust that disrupt the magnetic signal; careful inspection with a magnifying glass is necessary.
Intermittent wiring faults can be temperature or vibration dependent, so a wiggle test while monitoring live data is more reliable than a static resistance check.
This code can be set by a weak or failing wheel bearing that affects the tone ring alignment, even if the sensor itself is good.
Some vehicles use the left rear wheel speed signal for speedometer and cruise control; a fault here can cause those systems to act up, leading to misdiagnosis of unrelated components.

Can I keep driving with C0041?

The vehicle remains safe to drive under normal conditions because the base brakes still function, but the ABS and stability control systems may be disabled, increasing stopping distances on slippery surfaces. Avoid hard braking or driving in low-traction conditions until the fault is repaired.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

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