What Does C0221 Mean?
This code indicates the ABS control module has detected an open circuit in the right front wheel speed sensor circuit. The sensor, which monitors wheel rotation speed for the ABS, traction control, and stability control systems, is either not sending a signal or the wiring path between the sensor and control module is broken. This prevents the control module from receiving critical wheel speed data from the right front wheel.
Safety Warning
ABS, traction control, and stability control systems will be disabled, increasing stopping distances on slippery surfaces and risk of wheel lockup during hard braking. The ABS warning light will remain illuminated. Continue driving with extreme caution and repair immediately.
Common Causes
45%
Damaged, corroded, or disconnected wheel speed sensor connector or wiring harness
35%
Failed right front wheel speed sensor with internal open circuit
15%
Physical damage to sensor wiring from road debris, tire rubbing, or improper brake/suspension service
5%
Failed ABS control module internal circuit or corroded module connector pins
Diagnostic Steps
1
Step 1: Perform visual inspection of right front wheel speed sensor, wiring harness, and connector for physical damage, corrosion, disconnection, or signs of chafing. Check for debris buildup around sensor and tone ring.
2
Step 2: Using a digital multimeter, measure resistance across the wheel speed sensor terminals (sensor disconnected). Typical passive sensors should read 800-1400 ohms; active sensors will vary by manufacturer. An infinite reading confirms open circuit in sensor.
3
Step 3: Check continuity of sensor wiring from sensor connector to ABS control module connector using a wiring diagram. Verify both signal and ground wires have continuity and no shorts to ground or power.
4
Step 4: Inspect sensor air gap between sensor tip and reluctor ring/tone wheel (passive sensors only). Typical specification is 0.020-0.050 inches. Check tone ring for damage, missing teeth, or excessive runout.
5
Step 5: If wiring and sensor test good, inspect ABS module connector for corrosion, bent pins, or moisture intrusion. Check module ground connections are secure and clean.
6
Step 6: Replace faulty component (sensor or repair wiring), clear codes, and perform a test drive at various speeds (above 15 mph) while monitoring live wheel speed data to verify all four sensors are reading and tracking properly.
Estimated Repair Cost
$120 - $450
Parts + labor, varies by vehicle and location
This code indicates the ABS control module has detected an open circuit in the right front wheel speed sensor circuit. The sensor, which monitors wheel rotation speed for the ABS, traction control, and stability control systems, is either not sending a signal or the wiring path between the sensor an...
The most common cause of C0221 (Right Front Wheel Speed Sensor Circuit Open) is: Damaged, corroded, or disconnected wheel speed sensor connector or wiring harness
Typical repair costs for C0221 range from $120 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
ABS, traction control, and stability control systems will be disabled, increasing stopping distances on slippery surfaces and risk of wheel lockup during hard braking. The ABS warning light will remain illuminated. Continue driving with extreme caution and repair immediately.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C0221 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Chassis
System
Anti-lock Braking System (ABS) / Traction Control / Stability Control
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
