DTC Code | DTC Name |
---|---|
C1246 | Master Cylinder Pressure Sensor Malfunction |
C1281 | 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 is cleared when the Lost Booster Pressure Judgment Check is performed correctly in Test Mode and the check indicates a pass, or when Test Mode ends. DTC C1281 is output only in Test Mode.
DTC No. | DTC Detection Condition | Trouble Area |
---|---|---|
C1246 | Any of the following is detected:
|
|
C1281 | Detected only during Test Mode. |
|
WIRING DIAGRAM
Refer to DTCs C1249 and C1429 Click here and Click here.
INSPECTION PROCEDURE
PROCEDURE
CHECK STOP LIGHT OPERATION
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 LIGHTING SYSTEM (STOP LIGHT CIRCUIT) Click here |
OK |
READ VALUE USING TECHSTREAM (MASTER CYLINDER PRESSURE SENSOR)
Connect the Techstream to the DLC3.
Start the engine.
Select the Data List using the Techstream Click here.
Tester Display | Measurement Item/Range | Normal Condition | Diagnostic Note |
---|---|---|---|
Master Cylinder Sensor | Master cylinder pressure sensor reading / Min.: 0.00 V, Max.: 5.00 V | Brake pedal released: 0.20 to 0.40 V | Reading increases when brake pedal is depressed |
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, the voltage displayed on the Techstream increases. |
NG |
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
OK |
READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY AND BRAKE PEDAL LOAD SENSING SWITCH)
Select the Data List using the Techstream Click here.
Tester Display | Measurement Item/Range | Normal Condition | Diagnostic Note |
---|---|---|---|
Stop Light SW | Stop light switch / ON or OFF | ON: Brake pedal depressed OFF: Brake pedal released |
- |
Brake Pedal Load Sensing SW | Brake pedal load sensing switch / ON or OFF | ON: Brake pedal depressed beyond a specified point OFF: Brake pedal not depressed beyond a specified point |
- |
Check that the stop light switch display and brake pedal load sensing switch display observed on the Techstream change according to brake pedal operation.
OK |
---|
The Techstream displays on or off according to brake pedal operation. |
Slowly depress the brake pedal, and check when the stop light switch and brake pedal load sensing switch turn on.
OK |
---|
First the stop light switch should turn ON, and then the brake pedal load sensing switch should turn ON. |
Result | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
|
B |
CHECK HARNESS AND CONNECTOR (STP TERMINAL) Click here |
C |
CHECK BRAKE PEDAL LOAD SENSING SWITCH Click here |
D |
CHECK BRAKE PEDAL AND STOP LIGHT SWITCH ASSEMBLY INSTALLATION Click here |
A |
RECONFIRM DTC
Turn the ignition switch off.
Clear the DTCs Click here.
Turn the ignition switch off.
Start the engine.
At a speed of 30 km/h (18 mph) or more, drive the vehicle and perform a braking test (decelerate the vehicle by depressing the brake pedal).
Check if the same DTC is output Click here.
Result | ||||||
---|---|---|---|---|---|---|
|
B |
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
A |
CHECK FOR INTERMITTENT PROBLEMS Click here
CHECK HARNESS AND CONNECTOR (STP TERMINAL)
*a | Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly)) |
Turn the ignition switch off.
Make sure that there is no looseness at the locking part and the connecting part of the connector.
Disconnect the skid control ECU connector.
Measure the voltage according to the value(s) in the table below.
Standard Voltage | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Tech Tips
*: The standard voltage value varies depending on the +BS terminal voltage value. The standard voltage is 85% of the +BS terminal voltage.
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT) |
OK |
REPLACE BRAKE ACTUATOR ASSEMBLY Click here
CHECK BRAKE PEDAL LOAD SENSING SWITCH
*a | Component without harness connected (Brake Pedal Load Sensing Switch (Brake Pedal Support Assembly)) |
Turn the ignition switch off.
Make sure that there is no looseness at the locking part and the connecting part of the connector.
Disconnect the brake pedal load sensing switch connector.
Note
Do not remove the brake pedal load sensing switch from the brake pedal support assembly.
When there is a malfunction in the brake pedal load sensing switch, replace the brake pedal support assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
NG |
REPLACE BRAKE PEDAL SUPPORT ASSEMBLY Click here |
OK |
CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE PEDAL LOAD SENSING SWITCH)
Make sure that there is no looseness at the locking part and the connecting part of the connector.
Disconnect the skid control ECU connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
REPLACE BRAKE ACTUATOR ASSEMBLY Click here
CHECK BRAKE PEDAL AND STOP LIGHT SWITCH ASSEMBLY INSTALLATION
Turn the ignition switch off.
Check the brake pedal height and stop light switch assembly installation Click here.
OK |
---|
The brake pedal height and stop light switch assembly installation are normal. |
NG |
ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH ASSEMBLY Click here |
OK |
REPLACE BRAKE PEDAL SUPPORT ASSEMBLY Click here