Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC) - Vehicle Stability Control System

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1246/46,C1281/81: Master Cylinder Pressure Sensor Malfunction
C1281/81 - Master Cylinder Pressure Sensor Output Malfunction (Test Mode DTC)

DESCRIPTION

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

DTC C1281/81 will be cleared 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.









WIRING DIAGRAM

Refer to DTC C1249/49 C1249.

INSPECTION PROCEDURE

PROCEDURE

1. CHECK STOP LIGHT OPERATION

(a) Check that the stop light comes on when the brake pedal is depressed, and goes off when the brake pedal is released.

OK:





NG -- INSPECT STOP LIGHT CIRCUIT Exterior Lighting System
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (MASTER CYLINDER PRESSURE SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Select the Data List on the Techstream Data List / Active Test.

ABS/VSC/TRAC

ABS/VSC/TRAC:

(d) Check that the brake fluid pressure value of the master cylinder pressure sensor observed on the Techstream changes when the brake pedal is depressed.

OK:

When the pedal is depressed, voltage displayed on the Techstream increases.

NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
OK -- Continue to next step.

3. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)

(a) Select the Data List on the Techstream Data List / Active Test.

ABS/VSC/TRAC

ABS/VSC/TRAC:

(b) Check that the stop light condition observed on the Techstream changes when the brake pedal is depressed.

OK:

When the brake pedal is depressed, the Techstream displays "ON".

NG -- INSPECT SKID CONTROL ECU (STP TERMINAL)
OK -- Continue to next step.

4. RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Start the engine.

(d) At a speed of 30 km/h (18 mph) or more, drive the vehicle and perform braking test (decelerate the vehicle by depressing the brake pedal).

(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:





B -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

5. INSPECT SKID CONTROL ECU (STP TERMINAL)

(a) Turn the ignition switch off.





(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(c) Disconnect the skid control ECU connector.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration

Text in Illustration:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal