C0274 — Right Front Wheel Speed Sensor Circuit

Causes

• Damaged or corroded sensor connector
• Broken, pinched or shorted wiring to the right front wheel speed sensor
• Failed wheel speed sensor (active or passive)
• Damaged or missing tone ring/reluctor or excessive air gap
• Contamination (metal shavings, rust) on tone ring or sensor
• Poor ground or power supply to an active sensor

Symptoms

• ABS warning lamp and/or traction control/stability light ON
• ABS/ESC may be disabled or behave unpredictably
• Traction control or ABS intervention may not operate correctly
• Possible speedometer or cruise control irregularities (on some vehicles)
• Brake pulsation or unexpected ABS activation under braking (less common)

What to check

• Scan with a diagnostic tool: read freeze frame and live wheel speed sensor data
• Visually inspect the right front sensor, connector, and wiring for damage or corrosion
• Check for DTCs for other wheel sensors or communication faults
• Backprobe connector with ignition ON and check reference power/ground (for active sensors)
• Measure sensor resistance (passive) or supply voltage (active) per manufacturer spec
• Perform a wiggle test on wiring while monitoring live data for intermittent changes

Signal parameters

• Passive (magnetic/inductive) sensor: resistance typically tens to hundreds of ohms; produces an AC voltage proportional to wheel speed (low at idle, increases with speed)
• Active (hall/effect) sensor: has a 5 V or 12 V reference and ground; outputs a square/pulse signal (0–5 V) with frequency proportional to wheel speed
• At rest: sensor output should be steady (zero or reference voltage); when wheel rotates: a regular pulse waveform with frequency increasing with speed
• Intermittent drops, stuck high/low, or noisy waveforms indicate wiring/sensor/tone ring issues

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