Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VIWC
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 - 11/2017]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1425; Open in Stop Light Switch Circuit; 2016 - 2017 MY Sienna [12/2015 - 11/2017]

DTC

C1425

Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU (housed in the actuator assembly) inputs stop light switch signals and the condition of brake operation.

The skid control ECU has an open detection circuit, which outputs this DTC when detecting an open in the stop light input line or the ground line of the stop light circuit with the stop light switch off (brake pedal not depressed).

DTC Code

DTC Detection Condition

Trouble Area

C1425

When IG1 terminal voltage is between 9.5 and 17.4 V, an open stop light switch circuit continues for 3 seconds or more.
  • STOP fuse
  • Stop light switch assembly
  • Stop light switch circuit
  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When replacing the brake actuator assembly, perform zero point calibration and store system information (See page 2016 - 2017 MY Sienna [12/2015 - 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 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

Condition

Illumination Condition

Brake pedal depressed

ON

Brake pedal released

OFF
NG

GO TO STEP 4

OK

2.

READ VALUE USING TECHSTREAM (STOP LIGHT SW)

(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) According to the display on the Techstream, read the Data List.

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 switch display 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 9

OK

3.

RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs (See page 2016 - 2017 MY Sienna [12/2015 - 11/2017]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

(c) Start the engine.

(d) Depress the brake pedal several times to test the stop light circuit.

(e) Check if the same DTC is recorded (See page 2016 - 2017 MY Sienna [12/2015 - 11/2017]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

Result

Result

Proceed to

DTC (C1425) is not output

A

DTC (C1425) is output

B

HINT:

If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See page 2016 MY Sienna [12/2015 - 08/2016]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE 2017 MY Sienna [08/2016 - 11/2017]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE ).

A

USE SIMULATION METHOD TO CHECK

(See page 2016 MY Sienna [12/2015 - 08/2016]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: HOW TO PROCEED WITH TROUBLESHOOTING 2017 MY Sienna [08/2016 - 11/2017]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: HOW TO PROCEED WITH TROUBLESHOOTING )
B

REPLACE BRAKE ACTUATOR ASSEMBLY

4.

INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) for Bulb Type Stop Light

(1) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

1 - 2

Switch pin released

Below 1 Ω

Switch pin pushed in

10 kΩ or higher

Text in Illustration

*a

Component without harness connected

(Stop Light Switch Assembly)

(b) for LED Type Stop Light

(1) Reconnect the stop light switch assembly connector.

(2) Measure the resistance according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

A59-2 (L) - A59-3 (GND)

Switch pin released

8 to 14 V

Switch pin pushed in

Below 1.5 V

Text in Illustration

*a

Component with harness connected

(Stop Light Switch Assembly)

Result

Result

Proceed to

OK (w/ Dynamic radar cruise control)

A

OK (w/o Dynamic radar cruise control)

B

NG

C
B

GO TO STEP 7

C

REPLACE STOP LIGHT SWITCH ASSEMBLY

A

5.

CHECK HARNESS AND CONNECTOR (SWITCH INPUT TERMINAL)

(a) Turn the ignition switch off.

(b) Remove the stop light control relay (STOP LP relay).

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

Stop light control relay (STOP LP relay) terminal 4 - Body ground

Stop light switch assembly ON (Brake pedal depressed)

8 to 14 V

Stop light control relay (STOP LP relay) terminal 4 - Body ground

Stop light switch assembly OFF (Brake pedal released)

Below 1.5 V

Text in Illustration

*1

Engine Room Relay Block

*2

STOP LP Relay Holder
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (SWITCH INPUT CIRCUIT)
OK

6.

INSPECT STOP LIGHT CONTROL RELAY

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 - 4

Voltage is not applied between terminals 1 and 2

Below 1 Ω

3 - 4

Voltage is applied between terminals 1 and 2

10 kΩ or higher

Text in Illustration

*1

Stop Light Control Relay (STOP LP Relay)
NG

REPLACE STOP LIGHT CONTROL RELAY
OK

7.

CHECK HARNESS AND CONNECTOR (STP1 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 A4 skid control ECU (brake actuator assembly) connector.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A4-2 (STP1) - Body ground

Stop light switch assembly ON (Brake pedal depressed)

8 to 14 V

A4-2 (STP1) - 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))

HINT:

If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts (See page 2016 MY Sienna [12/2015 - 08/2016]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE 2017 MY Sienna [08/2016 - 11/2017]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE ).
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP1 CIRCUIT)
OK

8.

RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Reconnect the A4 skid control ECU (brake actuator assembly) connector.

(c) Clear the DTCs (See page 2016 - 2017 MY Sienna [12/2015 - 11/2017]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

(d) Turn the ignition switch off.

(e) Start the engine.

(f) Depress the brake pedal several times to test the stop light circuit.

(g) Check if the same DTC is output (See page 2016 - 2017 MY Sienna [12/2015 - 11/2017]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DTC CHECK / CLEAR ).

Result

Result

Proceed to

DTC C1425 is not output.

A

DTC C1425 is output.

B

HINT:

  • If the lighting system is normal but the DTC is still output, replace the skid control ECU (brake actuator assembly).
  • If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See page 2016 MY Sienna [12/2015 - 08/2016]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE 2017 MY Sienna [08/2016 - 11/2017]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE ).
A

USE SIMULATION METHOD TO CHECK

(See page 2016 MY Sienna [12/2015 - 08/2016]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: HOW TO PROCEED WITH TROUBLESHOOTING 2017 MY Sienna [08/2016 - 11/2017]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: HOW TO PROCEED WITH TROUBLESHOOTING )
B

INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT)

(See page 2016 MY Sienna [12/2015 - 08/2016]; LIGHTING (EXT): LIGHTING SYSTEM: PROBLEM SYMPTOMS TABLE 2017 MY Sienna [08/2016 - 11/2017]; LIGHTING (EXT): LIGHTING SYSTEM: PROBLEM SYMPTOMS TABLE )

9.

CHECK HARNESS AND CONNECTOR (STP1 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 (brake actuator assembly) connector.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A4-2 (STP1) - Body ground

Stop light switch assembly ON (Brake pedal depressed)

8 to 14 V

A4-2 (STP1) - 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))

HINT:

If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts (See page 2016 MY Sienna [12/2015 - 08/2016]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE 2017 MY Sienna [08/2016 - 11/2017]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: PROBLEM SYMPTOMS TABLE ).
OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP1 CIRCUIT)