How severe is fault code C1142?

Serious — Stop or limit driving

OBD Code C1142: Wheel Speed Sensor RF Tone Ring Tooth Missing Fault

Q: What does OBD code C1142 mean?

Wheel Speed Sensor RF Tone Ring Tooth Missing Fault. The right front wheel speed sensor detects a missing tooth on the tone ring (a gear-like ring that the sensor reads), similar to how a record player skips when a groove is damaged. This prevents the ABS and stability control systems from accurately measuring that wheel's speed.

Q: What are the symptoms of fault code C1142?

ABS warning light illuminated on dashboard, Traction control or stability control disabled or malfunctioning, Potential loss of ABS braking assistance during emergency stops

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What This Actually Means

In plain language — no jargon

The right front wheel speed sensor detects a missing tooth on the tone ring (a gear-like ring that the sensor reads), similar to how a record player skips when a groove is damaged. This prevents the ABS and stability control systems from accurately measuring that wheel's speed.

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Symptoms You May Notice

3 known symptoms for this code

ABS warning light illuminated on dashboard

Traction control or stability control disabled or malfunctioning

Potential loss of ABS braking assistance during emergency stops

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Embedded Systems Insight

What the ECU/ECM is actually computing

The ECU monitors the pulse frequency from the RF wheel speed sensor as the tone ring rotates past the sensor. It expects a consistent tooth-per-revolution pattern; a missing tooth creates an abnormal gap in the signal sequence. When the ECU detects this irregular spacing or signal dropout, it triggers the fault code.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Tooth spacing consistency	Uniform gaps between sensor pulses	Irregular or missing pulse indicating damaged tone ring
Signal frequency variation	Expected teeth count per wheel rotation	Frequency mismatch or signal loss detection

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Wheel Speed Sensor RF

Replace the right front wheel speed sensor; it may be damaged or misaligned and unable to read the tone ring correctly.

2

Right Front Tone Ring

Inspect and replace the tone ring on the right front wheel bearing or hub if teeth are visibly broken or chipped.

3

Wheel bearing assembly RF

Replace the entire right front wheel bearing hub assembly if the tone ring is integral and damaged beyond repair.