DTC C1246/46 Master Cylinder Pressure Sensor Malfunction; DTC C1281/81 Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC): Description

The master cylinder pressure sensor is connected to the skid control ECU in the brake actuator assembly. DTC C1281/81 will be deleted when the master cylinder pressure sensor sends a master cylinder pressure signal or when Test Mode ends. DTC C1281/81 is output only in Test Mode.

Fig 1: Master Cylinder Pressure Sensor Communication Diagram

DTC DETECTION CONDITION AND TROUBLE AREA REFERENCE CHART

DTC Code	DTC Detection Condition	Trouble Area
C1246/46	Any of the following is detected: At a vehicle speed of 7 km/h (4.3 mph) or more, when the PMC terminal voltage is between 0.86 and 1 V, it does not change by approx. 0.01 V or more for 30 seconds. At a vehicle speed of 7 km/h (4.3 mph) or more, when the PMC terminal voltage is over 1 V, it does not change by approx. 0.01 V or more for 60 seconds. Noise occurs in the PMC terminal 7 times or more within 5 seconds. When the stop light switch is OFF, the PMC terminal voltage is more than 0.86 V or less than 0.27 V for 5 seconds or more. With the IG1 terminal voltage between 9.5 and 17.2 V, the VCM terminal voltage is not between 4.4 and 5.6 V for 1.2 seconds or more. When the VCM terminal voltage is between 4.8 and 5.2 V, the PMC terminal voltage is not between 0.19 and 4.57 V for 1.2 seconds or more.	Stop light switch circuit Master cylinder pressure sensor circuit Brake actuator assembly (Master cylinder pressure sensor)
C1281/81	Detected only during Test Mode.	Stop light switch Master cylinder pressure sensor