C1228: Left Rear Wheel Speed Sensor Short to Ground
The C1228 code indicates a short to ground in the left rear (LR) wheel speed sensor circuit. The ABS or BCM module detects an abnormal voltage drop to zero from the sensor signal, meaning the signal wire is making direct contact with chassis ground. This fault compromises the ABS and traction control systems' ability to monitor LR wheel rotation. Upon detecting an invalid electrical signal, the module disables active safety functions that rely on this sensor to prevent erratic braking actions.
1. Commonly Affected Makes
2. Most Common Causes
- Left rear wheel speed sensor wiring shorted to ground
- Internally damaged left rear wheel speed sensor
- Corroded, bent, or grounded terminals at the sensor or ABS module connector
- Faulty ABS control module
3. Symptoms You Will Notice
- ABS warning light illuminated
- Traction control light on
- Possible loss of ABS and traction control functions
4. Step-by-Step Diagnosis
Scan for additional codes and verify C1228 is present
Visually inspect left rear wheel speed sensor wiring for damage or rubbing against chassis
Disconnect sensor and measure resistance between signal pin and ground; should be infinite (open)
Check connector terminals for corrosion, bent pins, or moisture
If wiring and sensor check out, test ABS module for internal short or replace as needed
5. Frequently Asked Questions
Is it safe to drive?▼
Driving is possible but not recommended because ABS and traction control will be disabled, increasing the risk of wheel lockup or loss of control in slippery conditions. Have it repaired promptly.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the issue is a damaged wire (cheaper) or a faulty sensor or ABS module (more expensive).