Pinpoint Test X : C1021:21, C1021:22: Notes
Refer to Vehicle Dynamic Systems for schematic and connector information.
Normal Operation and Fault Conditions
The ABS module uses several pressure sensors to monitor the brake system by comparing the input from the pressure sensors to other sensor input.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| C1021:21 | ABS Booster Control Pressure: Signal Amplitude < Minimum | This DTC sets in continuous memory and on-demand when the actual brake fluid pressure is less than what is demanded for system operation. |
| C1021:22 | ABS Booster Control Pressure: Signal Amplitude > Maximum | This DTC sets in continuous memory and on-demand when the actual brake fluid pressure is greater than what is demanded for system operation. |
Possible Causes
- Other Diagnostic Trouble Codes (DTCs) present in ABS module
- Brake fluid leak
- Air trapped in the brake system
- Master cylinder
- Brake booster
- ABS module