Possible causes
– Faulty Right Front Speed Sensor
– Right Front Speed Sensor harness is open or shorted
– Right Front Speed Sensor circuit poor electrical connection
– Faulty EBCM
– Right Front Speed Sensor harness is open or shorted
– Right Front Speed Sensor circuit poor electrical connection
– Faulty EBCM
Symptoms
– ABS Warning Light ON
C0221 GMC Description
As the wheel spins, the wheel speed sensor produces an Alternating Current (AC) signal. The Electronic Brake Control Module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.
GMC Technical Service Bulletins for C0221 code
2004 GMC CANYON SERVICE BRAKES, AIR:ANTILOCK:ABS WARNING LIGHT
2005 GMC CANYON SERVICE BRAKES, AIR:ANTILOCK:ABS WARNING LIGHT
2006 GMC CANYON SERVICE BRAKES, AIR:ANTILOCK:ABS WARNING LIGHT
2007 GMC CANYON SERVICE BRAKES, AIR:ANTILOCK:ABS WARNING LIGHT
2008 GMC CANYON SERVICE BRAKES, HYDRAULIC:ANTILOCK:ABS WARNING LIGHT
2003 GMC SAFARI SERVICE BRAKES, AIR:ANTILOCK:WHEEL SPEED SENSOR
2004 GMC SAFARI SERVICE BRAKES, AIR:ANTILOCK:WHEEL SPEED SENSOR
2004 GMC CANYON ELECTRICAL SYSTEM
2004 GMC CANYON SERVICE BRAKES, HYDRAULIC:ANTILOCK:ABS WARNING LIGHT
2005 GMC CANYON SERVICE BRAKES, HYDRAULIC:ANTILOCK:ABS WARNING LIGHT