C121E Code: Meaning, Causes, and Symptoms | OBD2 Codes

C121E – Brake Pressure Sensor Comparative Performance

 

C121E Possible Symptoms

 

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

 

C121E Possible Causes

 

Air in Brake System,Faulty Brake Switch,Brake Switch harness is open or shorted,Brake Switch circuit poor electrical connection,Faulty Anti-Lock Brake System (ABS) Module

 

C121E Description

 

The Anti-Lock Brake System (ABS) Module monitors the Brake Pressure Sensor. The ABS Module sets the OBDII code when the Brake Pressure Sensor is not to factory specifications.