DTC C1246: Master Cylinder Pressure Sensor Malfunction; DTC C1281: Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC) [08/2013 - 12/2013]: Description

The master cylinder pressure sensor is connected to the skid control ECU in the brake actuator assembly.

DTC C1281 is cleared when the Lost Booster Pressure Judgment Check is performed correctly in Test Mode and the check indicates a pass, or when Test Mode ends. DTC C1281 is output only in Test Mode.

Fig 1: Master Cylinder Pressure Sensor Circuit - Wiring Diagram

DTC No.	DTC Detection Condition	Trouble Area
C1246	Any of the following is detected: The voltage of the sensor signal is out of range (below 0.129 V, above 3.29 V). An abnormality is detected in the skid control ECU internal sensor test. The sensor signal offset value is out of range.	Stop light switch circuit Master cylinder pressure sensor circuit Master cylinder pressure sensor (Brake actuator assembly)
C1281	Detected only during Test Mode.	Stop light switch assembly Brake pedal load sensing switch (Brake pedal support assembly) Brake booster assembly Master cylinder pressure sensor (Brake actuator assembly)