C0046 critical

Left Rear Wheel Speed Sensor Circuit Low

The C0046 code means the vehicle's onboard diagnostic system has detected: Left Rear Wheel Speed Sensor Circuit Low. This is a critical severity code.

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Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$100 - $400 (parts and labor)
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Common Symptoms

  • ABS warning light on
  • Left Rear wheel speed reads zero on scan tool
  • Traction control disabled
  • Stability control fault

Probable Causes (Ranked by Likelihood)

  • Failed left rear wheel speed sensor Very High
  • Open circuit in left rear sensor wiring High
  • Excessive sensor to tone ring air gap Moderate
  • Corroded sensor connector pins Low

Step-by-Step Diagnostic Procedure

  1. Check left rear wheel speed sensor voltage output

  2. Measure sensor air gap to tone ring

  3. Inspect sensor connector for corrosion

  4. Compare wheel speed readings across all wheels

Common Fixes by Vehicle

What techs usually find when diagnosing C0046 on specific vehicles — tap your vehicle for the fix and the exact part:

2000-2018 GM & domestic trucks moderate DIY

Right rear wheel speed sensor circuit fault mirrors C0041 on the opposite side — typically a failed sensor or harness damage at the rear axle. Check the tone/reluctor ring for rust or damage as well. Replace the right rear wheel speed sensor and route the new harness cleanly.

Labor: 1-2 hours
Common fix part Rear Wheel Speed Sensor (Right) View on Amazon→ Compare fitment at PartsGeek→

Frequently Asked Questions

What does code C0046 mean?

C0046 indicates a problem with the left rear wheel speed sensor circuit causing low signal output.

Can I drive with code C0046?

You can drive short distances, but ABS and traction control will be disabled. Avoid slippery roads.

How much does it cost to fix C0046?

Wheel speed sensor repairs typically cost $100 to $400 including parts and labor.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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