C0221 on GMC: How to Diagnose & Fix
Right Front Wheel Speed Sensor Circuit Open
1 GMC model · 1 documented issue · 1 critical · $180-$900 repair
C0221 on GMC by model: symptoms, diagnosis and fix
GMT800 SUVs commonly develop corrosion under the front wheel speed sensors or wear in the hub bearing assembly, which alters the low-speed wheel speed signal. The result is unexpected ABS activation at parking-lot speeds, longer stopping distances, and a pulsating brake pedal even on dry pavement. GM documented this condition in service bulletins and in safety recall 05V379, which covers 2000-2002 Yukon XL in salt-belt states, and owners frequently report replacing hub assemblies to cure it.
Common Symptoms
- ABS activates at 3-10 mph on dry roads
- brake pedal kicks back at low speed
- longer stopping distance near a stop sign
- ABS warning light
- grinding or humming from front wheel bearing
How to Fix
Scan ABS wheel speed data during a low-speed stop and compare left and right front sensor readings. If one sensor drops out, inspect for rust buildup under the sensor or excessive hub play; cleaning the sensor mounting surface may help temporarily, but many vehicles need a complete front hub/bearing assembly with integrated sensor. Clear ABS codes and road-test after repair.
Sources for this issue (2)
C0221 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does C0221 mean on a GMC?
C0221 stands for "Right Front Wheel Speed Sensor Circuit Open." This code indicates the ABS module detected an open circuit in the right front wheel speed sensor circuit — meaning the signal path is broken and no usable wheel-speed data is coming from that corner. The sensor provides essential input for ABS, traction control, and stability control, so those systems are usually disabled when the signal is lost. The ABS and possibly traction/brake warning lights will come on. Normal (non-ABS) braking remains available. On GMC it is documented across 1 model: Yukon XL.
What are the most common causes of C0221?
The most common causes of C0221 are: Open/broken wiring to the sensor, Failed right front wheel speed sensor, Disconnected or corroded sensor connector, Damaged harness near the wheel (flex/chafe point), Corrosion at the ABS module connector, Damaged tone (reluctor) ring, Poor ground in the sensor circuit. The specific cause varies by vehicle.
How much does it cost to fix C0221 on a GMC?
Published repair estimates on GMC range from $180 to $900 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.