Toyota Tacoma 2015-2018 Service Manual: Open in Stop Light Switch Circuit (C1425)

Toyota Tacoma 2015-2018 Service Manual / Brake Control / Dynamic Control Systems / Vehicle Stability Control System(for Hydraulic Brake Booster) / Open in Stop Light Switch Circuit (C1425)

DESCRIPTION

The skid control ECU (master cylinder solenoid) inputs stop light switch signals and the brake operation condition.

The skid control ECU (master cylinder solenoid) has an open detection circuit, which outputs this DTC when detecting an open circuit 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 the IG1 terminal voltage is between 9.5 and 17.4 V and the skid control ECU (master cylinder solenoid) STPO terminal output is off, an open in the stop light switch circuit (A to B, A to body ground) continues for 3 seconds or more.	Stop light switch circuit Skid control ECU (master cylinder solenoid)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When replacing the master cylinder solenoid, perform calibration (See page PROCEDURE ).

PROCEDURE

1.	CHECK STOP LIGHT SWITCH OPERATION

GO TO STEP 5

2.	READ VALUE USING TECHSTREAM (STOP LIGHT SW)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

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

ABS/VSC/TRAC

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	-

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

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

Standard:

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

USE SIMULATION METHOD TO CHECK

3.	CHECK HARNESS AND CONNECTOR (STP2 TERMINAL)

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP2 CIRCUIT)

4.	RECONFIRM DTC

(a) Clear the DTCs (See page (b) Turn the ignition switch off. ).

(b) Turn the ignition switch off.

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

(e) Check if the same DTC is output (See page Result ).

Result

Result	Proceed to
DTC is not output	A
DTC is output	B

USE SIMULATION METHOD TO CHECK

REPLACE MASTER CYLINDER SOLENOID

5.	CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

6.	INSPECT STOP LIGHT SWITCH ASSEMBLY

REPLACE STOP LIGHT SWITCH ASSEMBLY

7.	CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - STOP LP CTRL RELAY)

REPAIR OR REPLACE HARNESS OR CONNECTOR

8.	INSPECT STOP LP CTRL RELAY

REPLACE STOP LP CTRL RELAY

9.	CHECK HARNESS AND CONNECTOR (REAR COMBINATION LIGHT ASSEMBLY, HIGH MOUNTED STOP LIGHT ASSEMBLY - STOP LP CTRL RELAY)

REPAIR OR REPLACE HARNESS OR CONNECTOR

GO TO STEP 11

10.	INSPECT REAR COMBINATION LIGHT ASSEMBLY

USE SIMULATION METHOD TO CHECK

REPLACE REAR COMBINATION LIGHT ASSEMBLY

11.	INSPECT CENTER STOP LIGHT BULB

USE SIMULATION METHOD TO CHECK

REPLACE CENTER STOP LIGHT BULB

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Other materials:

Data List / Active Test
DATA LIST / ACTIVE TEST 1. DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. HINT: Using the Techstream to read the Data List allows t ...

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