C1703

Right Rear Sensor Circuit Failure

Chassis Chassis/Safety ABS wheel speed sensor 🔴 Serious — Stop or limit driving 🚫 Do Not Drive
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What This Actually Means

In plain language — no jargon

Your vehicle's right rear wheel speed sensor isn't sending a proper signal to the anti-lock brake system, like a broken speedometer for just that wheel. The car can't accurately measure that wheel's speed, which disrupts ABS and stability control functions.

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Symptoms You May Notice

3 known symptoms for this code
ABS warning light illuminated on dashboard
Stability control or traction control disabled or malfunctioning
Reduced braking performance or ABS not engaging during emergency stops
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors the AC voltage signal generated by the right rear wheel speed sensor as the wheel rotates. It compares signal amplitude, frequency, and consistency against expected thresholds for that vehicle speed. A missing, weak, or erratic signal triggers a circuit failure fault.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Sensor Signal Voltage 0.5–5.0V AC (wheel-speed dependent) Below 0.2V or no signal detected
Signal Frequency Consistency Smooth rise/fall matching wheel rotation Erratic, missing pulses, or frozen signal
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Wheel speed sensor connector
Clean and reseat the connector at the right rear wheel to remove corrosion and ensure proper contact.
2
Sensor wiring harness
Inspect the wiring from wheel to ABS module for cuts, pinches, or damaged insulation and repair as needed.
3
Right rear wheel speed sensor
Replace the sensor if connector and wiring are clean; they typically unscrew from the wheel hub assembly.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code C1703 is classified as a serious fault. If your check engine light is flashing — not just steady — pull over safely and do not continue driving. A flashing CEL indicates an active misfire or critical failure that can cause catalytic converter damage within minutes or permanent engine harm within miles. Contact a certified mechanic immediately. Do not attempt roadside repairs on high-severity codes unless you are trained to do so.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code C1703

What happens after you fix the fault

Once the fault is repaired, C1703 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.