C1142 — Wheel Speed Sensor RF Tone Ring Tooth Missing Fault

chassis (brakes/steering/suspension)

Is it safe to drive?

Drive with caution The base brakes usually still work, so careful driving is possible — but ABS and stability control are disabled, which lengthens stopping distances on slippery roads. Fix promptly and avoid harsh driving.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm C1142 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many C0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the ABS / stability control for damage, corrosion, chafing or poor contact.
Subsystem check Read all four wheel speed PIDs while driving slowly — the faulty sensor drops out or reads implausibly.
Subsystem check Inspect the sensor and tone ring for metal debris and damage near the hub.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm C1142 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for C1142 (parts and labor, USD, independent shop rates): Replace a wheel speed sensor: $120–$350; Repair sensor wiring: $80–$250; ABS module repair or replacement: $400–$1,200. Overall, fixing C1142 usually costs between $80 and $1,200. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What are the symptoms of C1142?

Drivers most often notice: ABS or ESC warning light on, brake pedal pulsation changes, speedometer or cruise control issues, ABS not operating during hard braking.

What is the most common cause of C1142?

The most common causes are: damaged tone (reluctor) ring on the hub, failed wheel speed sensor, faulty ABS module or pump motor.

Is it safe to drive with C1142?

The base brakes usually still work, so careful driving is possible — but ABS and stability control are disabled, which lengthens stopping distances on slippery roads. Fix promptly and avoid harsh driving.

Will C1142 clear itself?

Sometimes C1142 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What does OBD2 code C1142 mean?

Wheel Speed Sensor RF Tone Ring Tooth Missing Fault (C1142): a chassis (brakes/steering/suspension) fault affecting the ABS / stability control. Short, gentle driving to a shop is usually possible. Most often caused by damaged tone (reluctor) ring on the hub, failed wheel speed sensor, faulty ABS module or pump motor.

The ABS control module monitors each wheel's rotational speed through a sensor and a toothed ring mounted on the hub assembly. Code C1142 triggers when that monitoring circuit detects an interruption in the signal pattern from the right-front wheel — specifically, the module recognizes that one or more teeth are missing or damaged on the tone ring. The Powertrain Control Module or ABS controller stores this fault because a gap in the reluctor ring causes inconsistent speed readings that could compromise brake and stability systems.

When C1142 sets, the computer doesn't immediately assume the sensor itself has failed. The anti-lock system relies on comparing all four wheel speeds in real time. If one sensor reports a sudden jump or drop that doesn't match the others, the module flags the discrepancy. The tone ring — sometimes called a reluctor — must produce a clean, predictable pattern as it passes the sensor's magnetic field. Any missing tooth breaks that rhythm, and the control unit interprets it as a fault condition. The freeze frame data captured alongside C1142 records engine RPM, vehicle speed, load, and temperature at the moment of detection, giving technicians a precise snapshot of the operating conditions that triggered the code.

The module requires multiple fault detections under specific driving conditions before illuminating the dashboard warning light. This prevents false triggers from minor electrical noise or a single transient glitch. However, once the light is on, the ABS and electronic stability control systems have likely been disabled or placed in a limited-operation mode.

Common Symptoms

ABS warning lamp stays illuminated on the instrument cluster
Electronic Stability Control (ESC) indicator appears or flashes
Unusual brake pedal pulsation or vibration during stops
Inaccurate speedometer readings or intermittent cruise control operation
Reduced traction干预 during emergency maneuvers
Complete loss of anti-lock braking capability under hard braking

Common Causes

Physical damage to the right-front tone ring, including bent, broken, or missing teeth
Corrosion or water intrusion at the wheel speed sensor electrical connector
Wiring harness damage from road debris or chassis flexing
Blown fuse supplying power to the ABS control unit
Wheel speed sensor internal failure or magnet degradation
ABS hydraulic control unit or pump motor malfunction (less frequent)

How to Diagnose C1142

Connect a compatible OBD2 scanner, retrieve all stored codes, and record the freeze frame data associated with C1142. Note the vehicle speed, engine RPM, and temperature values — these pinpoint the conditions under which the fault occurred.
Search for any Technical Service Bulletins (TSB) relevant to the vehicle make and model. Manufacturers occasionally publish updates, recalibrations, or known-flash campaigns for ABS-related codes like C1142. Check the National Highway Traffic Safety Administration database or the manufacturer's website using the VIN.
Perform a thorough visual inspection of the right-front wheel speed sensor wiring and connector. Look for cracked insulation, broken wires near the strut or control arm, and any signs of corrosion at the pins. Gently tug on each wire to confirm solid continuity.
Using the scanner's live data function, monitor all four wheel speed PIDs during a slow test drive. The affected sensor will either drop to zero, spike erratically, or show a speed that diverges noticeably from the other three wheels.
Remove the right-front wheel and inspect the tone ring directly. Check for metal chips, deformation, rust pitting, or any teeth that appear sheared off. Also verify the sensor tip for cracks, contamination, or excessive wear.
Clear C1142 after the inspection, then drive the vehicle under conditions matching the freeze frame data. If the code reappears, the fault is confirmed and component-level testing should proceed.

Repair Options and Costs

Wheel speed sensor replacement typically runs $120 to $350 for parts and labor, depending on vehicle design and whether the sensor is press-fit or bolt-mounted.

If the wiring harness requires repair — including connector replacement, solder splices, or protective taping — budget $80 to $250 for professional diagnosis and repair.

In rare cases where the ABS module itself is faulty, repair or replacement costs range from $400 to $1,200, including programming or initialization procedures.

Total Cost Summary

The final invoice hinges entirely on which part is actually faulty. Independent shop labor rates average $75 to $125 per hour in most regions. For most vehicles, addressing the sensor or wiring keeps total charges below $350. Module replacement remains the priciest scenario but should only be considered after eliminating simpler causes. An accurate, systematic diagnosis before purchasing components is the most effective way to avoid unnecessary expense.

Can You Drive With C1142?

Standard friction brakes continue functioning normally, so the vehicle remains driveable in a technical sense. However, anti-lock and stability control systems will not intervene during emergency braking or when traction is lost. Stopping distances increase significantly on wet, icy, or uneven surfaces. Driving with this code active is not recommended for extended periods or in adverse weather. Schedule repair promptly and adjust driving style conservatively in the meantime.