C0040 on Honda: How to Diagnose & Fix
Right Front Wheel Speed Sensor Circuit
1 Honda model · 1 documented issue · $150-$1,200 repair
C0040 on Honda by model: symptoms, diagnosis and fix
Multiple Passport owners report persistent ABS warning lights, often traced to failed wheel speed sensors, damaged sensor wiring, or faults in the ABS hydraulic control unit. On older rust-belt vehicles, corrosion at connectors and tone ring damage are common contributors. When this occurs, normal braking usually remains, but anti-lock braking is disabled and the warning lamp stays on.
Common Symptoms
- ABS light on
- intermittent ABS activation
- loss of anti-lock braking function
- brake warning indicators with no obvious hydraulic leak
How to Fix
Scan the ABS module for stored codes, then inspect each wheel speed sensor, tone ring, and harness for rust damage or broken wiring. Measure sensor resistance and signal output while spinning the wheel, and inspect the hydraulic unit and grounds if no sensor fault is obvious. Repairing the correct corner sensor or wiring usually resolves the issue; hydraulic unit replacement is more expensive but sometimes necessary.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Honda 8-97125-316-2 right-front ABS wheel-speed sensorOEMHonda 8-97125-316-2
Confirm VIN, side and connec
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Sources for this issue (2)
C0040 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does C0040 mean on a Honda?
C0040 stands for "Right Front Wheel Speed Sensor Circuit." This is a brake/ABS-system code. The right front wheel speed sensor measures how fast that wheel is rotating and feeds that data to the anti-lock brake, traction control, and stability control systems. C0040 means the ABS module found an electrical problem in the right front wheel speed sensor circuit — for example an open circuit, a short, or a signal that is missing or out of range. You'll normally see the ABS and traction/stability lights come on, and those systems may shut off temporarily while your regular brakes keep working. On Honda it is documented across 1 model: Passport.
What are the most common causes of C0040?
The most common causes of C0040 are: Failed right front wheel speed sensor, Damaged, corroded or unplugged sensor wiring/connector, Damaged or rust-clogged tone/reluctor ring, Excessive air gap between sensor and tone ring, Wheel bearing wear affecting an integrated sensor, Water intrusion or corrosion at the connector, Faulty ABS control module (less common). The specific cause varies by vehicle.
How much does it cost to fix C0040 on a Honda?
Published repair estimates on Honda range from $150 to $1,200 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for C0040 on a different make?
View C0040 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.