C0302

Code

Generic C — Chassis

Right front wheel speed sensor circuit

Brand: Generic

Type: C — Chassis

Views: UK: 14 EN: 20 RU: 14

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Page language: EN

Causes

Open or short in the right-front wheel speed sensor wiring or connector
Corroded, loose or damaged sensor connector/pins
Failed wheel speed sensor (magnetic/Hall/VR)
Damaged or missing tone ring (reluctor) or excessive air gap
Contamination (metal shavings, debris) on tone ring or sensor
Failed ABS/traction control module or poor ground at module

Symptoms

ABS warning lamp and/or traction/stability control lamp illuminated
Traction/stability control may be disabled or behave abnormally
Speedometer or speed-related functions may be affected (vehicle dependent)
Pulsing brake pedal or ABS activation when not expected (in some cases)
Diagnostic trouble code C0302 stored; possible additional ABS communications codes

What to check

Use scan tool to read ABS module codes and live wheel speed sensor data on all four wheels
Visually inspect right-front wheel speed sensor, wiring harness, and connector for damage, corrosion or looseness
Check for correct connector seating and bent/missing pins; apply dielectric grease after repair
Measure sensor resistance (for passive/VR sensors) and compare to manufacturer spec
Check supply voltage and ground at sensor connector for active/Hall sensors with ignition ON
Spin wheel (safe jacking and support) and measure AC voltage (VR) or signal waveform/frequency (active) to confirm output

Signal parameters

Passive (VR) sensor: DC resistance roughly 500–2,000 ohms (varies by manufacturer); AC output increases with wheel speed (low speeds ~0.1–2 VAC, higher speeds several VAC)
Active (Hall or magnetoresistive) sensor: typically 5V reference or switched 12V supply; output is a digital square wave or 0.2–4.8 V pulsed signal, frequency proportional to wheel speed
Expected behavior: stationary wheel = no/very low signal; wheel rotation = regular pulses or sine/AC waveform with frequency increasing with speed
Intermittent or erratic amplitude/frequency, or constant 0 V / fixed voltage, indicates fault

Diagnostic algorithm

Safety: Park on level ground, chock wheels, use jack stands if lifting vehicle. Avoid working with vehicle supported only by a jack.
Scan tool: Record C0302 and any related codes; view live data for all wheel speeds while slowly rotating each wheel by hand or with the vehicle safely lifted. Note if the right-front shows no pulses or inconsistent readings.
Visual: Inspect right-front sensor, wiring, and connector for damage, corrosion, chafing, rodent damage, or loose connector. Repair obvious issues.
Connector/Pin check: Unplug connector, inspect pins for corrosion/bent pins, back-probe connector while commanding/turning ignition per sensor type to check supply and ground.
Resistance/continuity: For passive sensors measure DC resistance across sensor terminals and compare to spec. For open/short, repair wiring or replace sensor.
Signal generation test: With wheel raised and safe to spin, rotate wheel and measure AC voltage (VR) or use oscilloscope/scan tool to observe waveform from sensor; expect a clean periodic signal. Replace sensor if no valid signal.
Tone ring inspection: Check reluctor ring for missing/bent teeth, buildup, heavy rust, or damage. Clean or replace if necessary. Verify proper sensor-to-ring air gap per spec.
Wiggle test: While monitoring live data, flex harness and move suspension through travel to find intermittent open/short. Repair wiring and secure harness.
Verify module power/ground: If sensor/wiring OK, verify ABS module grounds and power feeds. Repair poor grounds or power faults.
Replace/repair: Replace sensor or repair wiring/connector as indicated. Clear codes, perform a test drive and re-scan to confirm fault does not return.
If code returns after repairs and wiring/sensor/module checks are good, consider ABS module internal fault or software issue and consult manufacturer service information.

Likely causes

Wiring/connector corrosion or broken wire at the wheel (most common)
Failed sensor due to contamination or impact
Damaged/missing teeth on the reluctor/tone ring or excessive sensor gap
Intermittent open/short caused by suspension motion or wheel bearing collapse
Less likely: faulty ABS module or poor module ground

Fault status

⚠️ Status

ABS/ESC warning lamp illuminated. Right front wheel speed sensor circuit fault stored in ABS module; associated traction/stability functions may be disabled.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2 hours