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

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM (w/ VDIM): C1246/46: 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 built into the brake actuator assembly.
DTC C1281/81 can be deleted when the master cylinder pressure sensor sends a master cylinder pressure signal or the Test Mode ends. DTC C1281/81 is output only in the Test Mode.






WIRING DIAGRAM





INSPECTION PROCEDURE
NOTE: When replacing the skid control ECU, perform zero point calibration and store system information Vehicle Stability Control System (W/ VDIM).

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
OK -- Continue to next step.
2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)
(a) Connect Techstream to the DLC3.
(b) Start the engine.
(c) Select the Data List mode on Techstream.

ABS / VSC / TRAC:





(d) Check that the stop light display observed on Techstream changes when the brake pedal is depressed.
OK:
When the brake pedal is depressed, Techstream displays "ON".
OK -- READ VALUE USING TECHSTREAM (MASTER CYLINDER PRESSURE SENSOR)
NG -- Continue to next step.
3. INSPECT SKID CONTROL ECU (STP1 TERMINAL)





(a) Disconnect the skid control ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP1 CIRCUIT)
OK -- REPLACE SKID CONTROL ECU
4. READ VALUE USING TECHSTREAM (MASTER CYLINDER PRESSURE SENSOR)
(a) Select the Data List mode on Techstream.

ABS / VSC/ TRAC:





(b) Check that the brake fluid pressure value of the master cylinder pressure sensor observed on Techstream changes when the brake pedal is depressed.
OK:
When the pedal is depressed, voltage displayed on Techstream increases.
OK -- RECONFIRM DTC
NG -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE ACTUATOR ASSEMBLY)





(a) Turn the engine switch off.
(b) Disconnect the skid control ECU connector and the brake actuator connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. INSPECT SKID CONTROL ECU (SENSOR INPUT)





(a) Reconnect the skid control ECU connector.
(b) Turn the engine switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPLACE SKID CONTROL ECU
OK -- Continue to next step.
7. INSPECT SKID CONTROL ECU (SENSOR OUTPUT)





(a) Reconnect the brake actuator connector.
(b) Remove either the right or left front brake cylinder bleeder plug.
(c) Install the pressure gauge via the attachment, and bleed the gauge of air Service and Repair.
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPLACE BRAKE ACTUATOR ASSEMBLY
OK -- Continue to next step.
8. RECONFIRM DTC
(a) Turn the engine switch off.
(b) Clear the DTC Vehicle Stability Control System (w/ VDIM).
(c) Start the engine.
(d) At a speed of 18 mph (30 km/h) 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 Vehicle Stability Control System (w/ VDIM).
Result:






B -- REPLACE SKID CONTROL ECU
A -- USE SIMULATION METHOD TO CHECK