C0055 – Wheel Speed Sensor Circuit

C0055 is a chassis-related diagnostic trouble code that usually points to a problem with a wheel speed sensor circuit, most often at one specific wheel. When this code sets, your ABS, traction control, or stability control systems may be partially or completely disabled. You might see warning lights, feel odd braking behavior, or notice your speedometer acting up. While C0055 is not usually an engine-damaging issue, it is a safety concern. Understanding what this code means, how it behaves, and how to fix it will help you avoid costly mistakes.

What Does C0055 Mean?

C0055 is a generic chassis (C-code) that most manufacturers use to indicate a fault in a wheel speed sensor circuit, commonly the rear right (RR) or rear left (RL) depending on the brand. The ABS module or electronic brake control module (EBCM) sets this code when it sees an abnormal, missing, or implausible signal from that wheel’s speed sensor.

In plain terms, the computer is telling you it cannot reliably read how fast that wheel is turning. When that happens, the ABS, traction control (TCS), and electronic stability control (ESC) systems can’t do their job correctly, so the module stores C0055 and usually turns on warning lights.

Quick Reference

• Code: C0055
• System: Chassis / ABS / Traction Control
• Typical Meaning: Fault in a wheel speed sensor circuit (often rear wheel)
• Severity: Moderate – safety/handling concern
• Common Fix: Wheel speed sensor or hub/bearing replacement, wiring repair

Real-World Example / Field Notes

In the shop, I see C0055 a lot on vehicles that live in rust-prone areas. A typical case: a customer comes in with an ABS and traction control light on, saying the system “kicks in” at low speeds or the brakes feel strange on dry pavement. Scan data shows one rear wheel speed reading zero or jumping around while the others look normal. On inspection, the sensor wiring is corroded and the tone ring built into the wheel bearing is rusted and cracked. Replacing the hub assembly and repairing the harness clears C0055 and restores normal braking behavior.

Symptoms of C0055

• ABS warning light illuminated on the dashboard
• Traction control or stability control light on or flashing
• Loss of ABS function, causing wheels to lock during hard braking
• Unusual ABS activation at low speeds or on dry pavement
• Inaccurate wheel speed data in scan tool live data
• Speedometer fluctuation or intermittent drop-out (on some vehicles)
• Longer stopping distances or unstable braking feel in slippery conditions
• Other ABS-related codes stored along with C0055

Common Causes of C0055

Most Common Causes

• Failed wheel speed sensor: Internal sensor failure from age, moisture intrusion, or impact damage is one of the top reasons for C0055.
• Damaged wiring or connector: Broken, corroded, or rubbed-through wires near the wheel or along the control arm can interrupt the sensor signal.
• Faulty wheel bearing with integrated sensor: Many modern hubs have the speed sensor built in; a worn bearing or damaged tone ring can cause erratic readings.
• Contamination on tone ring or encoder: Metal shavings, rust buildup, or heavy debris can distort the magnetic or toothed ring signal.
• Improper sensor gap: Incorrect installation or aftermarket parts that don’t seat properly can leave the sensor too far from the tone ring.

Less Common Causes

• ABS module (EBCM) failure: Internal faults in the ABS control unit can misread a good sensor and set C0055, though this is less frequent.
• Damaged tone ring on axle or CV joint: Cracked, missing teeth, or warped rings can create intermittent signals.
• Previous collision or suspension repair: Improper routing of the harness or physical damage from an accident can lead to intermittent opens or shorts.
• Water intrusion in connectors: Poorly sealed connectors or missing grommets allow moisture in, causing corrosion and high resistance.
• Incorrect or incompatible replacement parts: Using the wrong sensor or hub for your specific ABS system can cause a mismatch in signal type.

Diagnosis: Step-by-Step Guide

To diagnose C0055 correctly, you’ll want a basic scan tool that can read ABS codes, a digital multimeter, a jack and jack stands, and ideally a wiring diagram for your specific vehicle. An advanced scan tool that can view live wheel speed data and Mode $06 information makes the job easier, but you can still get far with basic tools if you’re methodical.

1. Confirm the code: Use a scan tool to verify C0055 is present and note whether it’s current or stored as history. Check for other ABS or chassis codes that may point to a shared issue.
2. Identify the affected wheel: Many manufacturers specify which wheel C0055 refers to (for example, rear right). If not, use live data to see which wheel shows abnormal or no speed reading.
3. Visual inspection: Safely raise the vehicle and inspect the suspected wheel speed sensor, wiring, and connector. Look for broken insulation, chafed wires, loose connectors, or obvious physical damage.
4. Check for corrosion and contamination: Unplug the sensor connector and inspect for green corrosion, bent pins, or moisture. Also inspect the sensor mounting area and tone ring for rust flakes or debris.
5. Test sensor resistance or output: With the sensor disconnected, measure resistance with a multimeter and compare it to factory specs. For some sensors, you can spin the wheel and look for an AC voltage signal while monitoring with the meter.
6. Wiggle test the harness: While monitoring live wheel speed data or sensor voltage, gently move the harness. If the reading cuts in and out, you likely have an internal break or bad connection.
7. Check power and ground: On active (powered) sensors, verify you have proper reference voltage and ground at the connector using a wiring diagram to identify the correct pins.
8. Inspect the tone ring or encoder: If the sensor tests good, remove it (if possible) and inspect the tone ring on the axle, CV joint, or hub. Look for cracks, missing segments, or heavy rust buildup.
9. Evaluate ABS module (last resort): Only after confirming the sensor, wiring, and tone ring are good should you suspect the ABS module. Use advanced diagnostics or a professional scan tool to perform module tests if available.
10. Clear codes and road test: After repairs, clear the DTCs and perform a road test while watching live wheel speed data to confirm all wheels read correctly and C0055 does not return.

Pro tip: Compare the suspect wheel’s speed reading to the others at low and moderate speeds. A sensor that lags, spikes, or drops out compared to the rest is often the culprit, even if it passes a basic resistance test.

Possible Fixes & Repair Costs

Most repairs for C0055 revolve around restoring a clean, consistent wheel speed signal. In many cases, that means replacing the sensor, repairing the harness, or installing a new hub assembly with an integrated sensor.

• Replace wheel speed sensor: Common on many vehicles. Parts typically run $40–$150; labor is about 0.5–1.0 hour in most shops.
• Replace hub/bearing assembly with integrated sensor: Parts often cost $120–$400 per side depending on vehicle; labor is usually 1–2.5 hours.
• Repair or replace wiring harness/connector: Minor repairs can be $75–$200; replacing a full harness section may run $200–$500.
• Clean or replace tone ring/encoder: Cleaning rust and debris is low cost if accessible; replacing a damaged ring or axle can range from $150–$600.
• ABS module replacement: Least common but most expensive. Expect $500–$1,200 or more including programming.

Typically, you’re looking at a total repair cost in the $150–$600 range for the most common C0055 issues, depending on parts prices, labor rates in your area, and whether additional components (like bearings or axles) are worn or seized and need extra work.

Can I Still Drive With C0055?

You can usually still drive with C0055 stored, but you need to understand the risk. With this code active, your ABS, traction control, and stability control may be partially or completely disabled. Under normal, dry conditions you may not notice much difference. However, in rain, snow, or emergency stops, your wheels are more likely to lock up and the vehicle can become harder to control. If the ABS light is on, drive cautiously and schedule diagnosis and repair as soon as you can, especially before bad weather or long trips.

What Happens If You Ignore C0055?

If you ignore C0055, you’re essentially driving without the electronic safety net your ABS and stability control systems provide. Over time, the underlying problem can worsen, leading to more severe wiring damage, bearing failure, or additional ABS codes. In the worst case, a failed hub or axle component can create a mechanical safety hazard, not just an electronic one. Fixing the issue early usually costs less and keeps your braking performance where it should be.

Last updated: March 1, 2026

Vehicles Commonly Affected by C0055

C0055 shows up across many brands, but it’s especially common on vehicles that use integrated wheel bearing and sensor assemblies. You’ll often see it on GM products (Chevrolet Silverado, GMC Sierra, Equinox, Malibu, Buick Enclave), various Ford and Lincoln SUVs and trucks, and many Nissan, Infiniti, and Hyundai/Kia models. Compact and midsize SUVs, pickups, and crossovers that see winter road salt or off-road use are particularly prone to sensor wiring corrosion and hub-related issues that trigger C0055.