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

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.

The master cylinder pressure sensor is built into 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.

DTC DETECTION CONDITION

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 over 0.86 V, it does not change by 0 005 V or more for 30 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 3 V for 5 seconds or more With the IG1 terminal voltage between 9 5 and 18 5 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 between 4 4 and 5 6 V, the PMC terminal voltage is not between 0 19 and 4 57 V for 1 2 seconds or more	Master cylinder pressure sensor Master cylinder pressure sensor circuit Stop light switch circuit Skid control ECU
C1281/81	Detected only during Test Mode	Stop light switch Brake pedal load sensing switch Master cylinder pressure sensor