Toyota CH-R Service Manual: Open in Stop Light Switch Circuit (C1425)

DESCRIPTION

The skid control ECU (brake actuator assembly) receives stop light switch signals and uses them to determine whether or not the brakes are applied.

The skid control ECU (brake actuator assembly) has a detection circuit that it uses to detect an open in the stop light input line.

If the skid control ECU (brake actuator assembly) detects an open in this circuit, it will store this DTC.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1425	Open in Stop Light Switch Circuit	An open in the stop light switch input line continues for 3 seconds or more.	Wire harness or connector Stop light switch assembly Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

Ref to DTC C1249.

Click here

CAUTION / NOTICE / HINT

PROCEDURE

1.	CHECK STOP LIGHT SWITCH 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 5

OK

2.	READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Select the Data List using the Techstream.

Click here

Chassis > ABS/VSC/TRAC/EPB > Data List

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	-

Chassis > ABS/VSC/TRAC/EPB > Data List

Tester Display
Stop Light SW

(d) 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 4

OK

3.	RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC/EPB > Clear DTCs

(c) Turn the ignition switch off.

(d) Start the engine.

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

(f) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC/EPB > Trouble Codes

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 before replacing parts.

Click here

A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY

4.	CHECK HARNESS AND CONNECTOR (STP TERMINAL)

(a) Turn the ignition switch off.

*a Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(c) Disconnect the A42 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
A42-44 (STP2) - Body ground	Stop light switch ON (Brake pedal depressed)	11 to 14 V*
A42-44 (STP2) - Body ground	Stop light switch OFF (Brake pedal released)	Below 1.5 V

HINT:

*: The standard voltage value varies depending on the +BS terminal voltage value. The standard voltage is 85% of the +BS terminal voltage.

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.

Click here

A

REPLACE BRAKE ACTUATOR ASSEMBLY

B

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

5.	INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Check the stop light switch assembly.

Click here

OK:

The stop light switch assembly is normal.

NG

REPLACE STOP LIGHT SWITCH ASSEMBLY

OK

6.	CHECK HARNESS AND CONNECTOR (STP TERMINAL)

(a) Reconnect the A45 stop light switch assembly connector.

*a Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(c) Disconnect the A42 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
A42-44 (STP2) - Body ground	Stop light switch ON (Brake pedal depressed)	11 to 14 V*
A42-44 (STP2) - Body ground	Stop light switch OFF (Brake pedal released)	Below 1.5 V

HINT:

*: 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

7.	RECONFIRM DTC

(a) Reconnect the A42 skid control ECU (brake actuator assembly) connector.

(b) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC/EPB > Clear DTCs

(c) Turn the ignition switch off.

(d) Start the engine.

(e) Drive the vehicle and depress the brake pedal several times to test the stop light circuit.

(f) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC/EPB > Trouble Codes

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 before replacing parts.

Click here

A

USE SIMULATION METHOD TO CHECK

B

INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT)