C1246

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1246/46,C1281/81: Master Cylinder Pressure Sensor Malfunction

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.









WIRING DIAGRAM










INSPECTION PROCEDURE
NOTE: When replacing the brake actuator assembly, perform zero point calibration Programming and Relearning.

PROCEDURE

1. CHECK STOP LIGHT OPERATION
(a) Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.
OK:






NG -- INSPECT STOP LIGHT CIRCUIT
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 Data List mode on the Techstream Data List / Active Test.

ABS/VSC/TRAC





(d) Check that the brake fluid pressure value of the master cylinder pressure sensor observed on the Techstream changes according to brake pedal operation.
OK:
When the pedal is depressed, voltage displayed on the Techstream increases.
NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- Continue to next step.

3. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)
(a) Select Data List mode on the Techstream Data List / Active Test.

ABS/VSC/TRAC





(b) Check that the stop light condition observed on the Techstream changes according to brake pedal operation.
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 Vehicle Stability Control System.
(c) Start the engine.
(d) Drive the vehicle at a speed of 30 km/h (19 mph) or more and perform braking test (decelerate the vehicle by depressing the brake pedal).
(e) Check if the same DTC is recorded Vehicle Stability Control System.
Result:






B -- REPLACE BRAKE ACTUATOR ASSEMBLY
A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)
5. INSPECT SKID CONTROL ECU (STP TERMINAL)




(a) Turn the ignition switch off.
(b) Disconnect the skid control ECU connector.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY