Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018KEO
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1422; Master Cylinder Pressure Sensor Zero Point High Malfunction; 2018 - 2020 MY Sienna [11/2017 -        ]

DTC

C1422

Master Cylinder Pressure Sensor Zero Point High Malfunction

DESCRIPTION

DTC Code

DTC Detection Condition

Trouble Area

C1422

When vehicle speed is 3 km/h (2 mph) or more and stop light switch assembly is OFF, master cylinder pressure continuously exceeds 1.764 MPa (18.0 kgf/cm2, 255 psi) for 5 seconds or more.

  • Stop light switch assembly
  • Wire harness or connector
  • Skid control ECU (brake actuator assembly)
  • Brake actuator assembly (Master cylinder pressure sensor)

WIRING DIAGRAM

Refer to DTC C1425 (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1425; Open in Stop Light Switch Circuit ).

CAUTION / NOTICE / HINT

NOTICE:

  • When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: CALIBRATION ).
  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.

CHECK DTC

(a) Clear the DTCs (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

(b) Turn the ignition switch off.

(c) Start the engine.

(d) Perform a road test.

(e) Check for DTCs (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

Result

Proceed to

DTC C1422 is output.

A

DTCs C1422 and C1425 are output.

B

B

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

A

2.

READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.

(e) Select the Data List using the Techstream (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DATA LIST / ACTIVE TEST ).

ABS/VSC/TRAC

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Stop Light SW

Stop light switch assembly / ON or OFF

ON: Brake pedal depressed

OFF: Brake pedal released

-

(f) Check that the stop light condition observed on the Techstream changes according to brake pedal operation.

OK:

The Techstream displays ON or OFF according to brake pedal operation.

NG

GO TO STEP 5

OK

3.

READ VALUE USING TECHSTREAM (MASTER CYLINDER PRESSURE SENSOR)

(a) Select the Data List using the Techstream (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DATA LIST / ACTIVE TEST ).

ABS/VSC/TRAC

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Master Cylinder Pressure

Master cylinder pressure sensor pressure / Min.: 0.00 MPa, Max.: 23.28 MPa

Brake pedal depressed: Proportional to pedal force

Brake pedal released: 0.00 to 1.76 MPa

-

OK:

Data List pressure is within standard range.

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

OK

4.

RECONFIRM DTC

(a) Clear the DTCs (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

(b) Turn the ignition switch off.

(c) Start the engine.

(d) Perform a road test.

(e) Check if the same DTC is output (See page 2018 - 2020 MY Sienna [11/2017 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

Result

Proceed to

DTC C1422 is not output.

A

DTC C1422 is output.

B

A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY

5.

CHECK BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION

(a) Turn the ignition switch off.

(b) Check the brake pedal height and stop light switch installation (See page 2016 - 2020 MY Sienna [12/2015 -        ]; BRAKE SYSTEM (OTHER): BRAKE PEDAL: INSTALLATION ).

OK:

The brake pedal height and stop light switch installation are normal.

NG

ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH ASSEMBLY

OK

6.

INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Inspect the stop light switch assembly (See page 2016 - 2020 MY Sienna [12/2015 -        ]; LIGHTING (EXT): STOP LIGHT SWITCH: ON-VEHICLE INSPECTION ).

NG

REPLACE STOP LIGHT SWITCH ASSEMBLY

OK

7.

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 connectors.

(c) Disconnect the skid control ECU (brake actuator assembly) connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

A75-35 (STP) - Body ground

Stop light switch assembly on (Brake pedal depressed)

8 to 14 V

A75-35 (STP) - Body ground

Stop light switch assembly off (Brake pedal released)

Below 1.5 V

Text in Illustration

*a

Front view of wire harness connector

(to Skid Control ECU (Brake Actuator Assembly))

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)