Set Conditions
WARNING: This page is about a different car, the 1999 Buick Regal and 1999 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
DTC C1221 can only be set :
- DTC C1232 through C1235 are not set as a current DTC(s)
- Vehicle is not in an ABS stop
- Brake switch is off
The DTC will set when left front wheel speed equals zero and the other wheel speeds are greater than 8 Km/h (5 mph) for 2.5 seconds.