C1021 Code: Meaning, Causes, and Symptoms | OBD2 Codes

C1021 – ABS Booster Control Pressure Signal Amplitude


C1021 Possible Symptoms


Anti-Lock Brake System (ABS) Warning Light ON,Engine Light ON (or Service Engine Soon Warning Light)


C1021 Possible Causes


Other Diagnostic Trouble Codes (DTCs) present in Anti-Lock Brake System (ABS) Module,Brake fluid leak,Air trapped in the brake system,Master cylinder,Brake booster,ABS module


C1021 Description


The Anti-Lock Brake System (ABS) Module uses several pressure sensors to monitor the brake system by comparing the input of the pressure sensors to other sensor input. This DTC indicates that other DTCs are present for the brake pedal angle sensor, the vacuum pressure sensor or a brake (fluid) pressure sensor.