C1425

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1425: Open in Stop Light Switch Circuit
C1425 - Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU (housed in the brake 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).

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.
* When replacing the brake actuator assembly, perform zero point calibration Component Tests and General Diagnostics.

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:

NG -- INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL)
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Select the Data List mode on the Techstream Data List / Active Test.

ABS/VSC/TRAC:

(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 -- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 1 RELAY BLOCK)
OK -- Continue to next step.

3. RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Start the engine.

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

(e) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result:

HINT
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.

B -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) How To Proceed With Troubleshooting

4. INSPECT STOP LIGHT SWITCH (POWER SOURCE TERMINAL)

(a) Make sure that there is no looseness in the locking part and connecting part of the connectors.

(b) Disconnect the stop light switch connector.

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

Standard Voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK -- Continue to next step.

5. INSPECT STOP LIGHT SWITCH

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

Standard Resistance:

NG -- REPLACE STOP LIGHT SWITCH Removal
OK -- Continue to next step.

6. INSPECT SKID CONTROL ECU (STP2 TERMINAL)

(a) Connect the stop light switch connector.

(b) Install the stop light control relay (BRK).

(c) Turn the ignition switch off.

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

(e) Disconnect the skid control ECU connector.

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

Standard Voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP2 CIRCUIT)
OK -- Continue to next step.

7. RECONFIRM DTC

(a) Connect the skid control ECU connector.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Start the engine.

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

(e) Check if the same DTC is output Reading and Clearing Diagnostic Trouble Codes.

Result:

HINT
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Problem Symptoms Table.

B -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) How To Proceed With Troubleshooting

8. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - ENGINE ROOM NO. 1 RELAY BLOCK)

(a) Turn the ignition switch off.

(b) Remove the stop light control relay (BRK).

(c) Make sure that there is no looseness in the locking part and connecting part of the connectors.

(d) Disconnect the skid control ECU connector.

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

Standard Resistance: