What Does C1235 Mean?
The ABS control module has detected an open or short circuit condition in the right rear wheel speed sensor circuit. This sensor provides critical rotational speed data to the ABS and traction control systems. Without a valid signal, the module cannot accurately modulate braking force to the right rear wheel during anti-lock events.
Safety Warning
ABS and traction control are likely disabled. Braking distances increase significantly on wet or slippery surfaces. Repair immediately before driving in adverse conditions.
Common Causes
35%
Damaged or failed right rear wheel speed sensor due to road debris impact or bearing failure
30%
Broken, chafed, or corroded wiring in the right rear wheel speed sensor harness exposed to road spray and salt
20%
Corroded or water-damaged connector at the sensor or at the ABS module causing intermittent or open circuit
10%
Damaged ABS tone ring on the right rear axle with missing or cracked teeth
5%
Internal ABS control module circuit failure on the right rear input channel
Diagnostic Steps
1
Step 1: Visually inspect the right rear wheel speed sensor, wiring harness, and connector for physical damage, corrosion, or contamination. Check sensor air gap (typical 0.020-0.050 inches).
2
Step 2: Measure sensor resistance with DVOM across the sensor terminals (typical 800-1400 ohms for passive sensor; active sensors should show ~5V reference). Compare to left rear sensor readings.
3
Step 3: Check for short to ground and short to battery on both sensor circuit wires at the ABS module connector using DVOM. Resistance to ground should be OL (open).
4
Step 4: Inspect the ABS tone ring through the sensor mounting hole or by removing the brake rotor/drum. Look for missing teeth, cracks, rust buildup, or metallic debris.
5
Step 5: Monitor right rear wheel speed via live data while spinning the wheel by hand. Signal should be smooth and consistent. Clear codes and test drive to verify repair.
Estimated Repair Cost
$100 - $400
Parts + labor, varies by vehicle and location
The ABS control module has detected an open or short circuit condition in the right rear wheel speed sensor circuit. This sensor provides critical rotational speed data to the ABS and traction control systems. Without a valid signal, the module cannot accurately modulate braking force to the right r...
The most common cause of C1235 (Right Rear Wheel Speed Circuit Open or Shorted) is: Damaged or failed right rear wheel speed sensor due to road debris impact or bearing failure
Typical repair costs for C1235 range from $100 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
ABS and traction control are likely disabled. Braking distances increase significantly on wet or slippery surfaces. Repair immediately before driving in adverse conditions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1235 to identify the root cause.
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Quick Info
Category
Chassis
System
Anti-lock Brake System (ABS) / Traction Control System
Difficulty
Type
Manufacturer
Recommended Tools
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