C1380

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1380: Stop Light Control Relay Malfunction
C1380 - Stop Light Control Relay Malfunction

DESCRIPTION

The skid control ECU inputs the stop light switch signal and detects the status of the brake operation.





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When replacing the master cylinder solenoid, perform zero point calibration Calibration.
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT
When DTC C1425 is output together with DTC C1380, inspect and repair the trouble areas indicated by DTC C1425 first C1425.

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:

Stop light switch function is normal.

NG -- INSPECT STOP LP CTRL RELAY
OK -- Continue to next step.

2. INSPECT SKID CONTROL ECU (STP TERMINAL)

(a) Disconnect the skid control ECU connector.





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

Standard Voltage:





Text in Illustration





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

3. INSPECT SKID CONTROL ECU (STP2 TERMINAL)

(a) Disconnect the skid control ECU connector.





(b) 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.

4. PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT RELAY)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.

ABS/VSC/TRAC





(f) Check that the stop lights turn on and off on the rear combination light when using the Techstream.

OK:

The stop lights turn on and off according to the Techstream operations.

NG -- CHECK STOP LP CTRL RELAY
OK -- Continue to next step.

5. RECONFIRM DTC

HINT
Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

Result





B -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

A -- REPLACE MASTER CYLINDER SOLENOID Disassembly

6. CHECK STOP LP CTRL RELAY

(a) Remove the STOP LP CTRL relay from the engine room relay block.





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

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. INSPECT STOP LP CTRL RELAY

(a) Remove the STOP LP CTRL relay from the engine room R/B No. 2.





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

Standard Resistance:





Text in Illustration





NG -- REPLACE STOP LP CTRL RELAY
OK -- Continue to next step.

8. INSPECT SKID CONTROL ECU (STOP TERMINAL)

(a) Disconnect the skid control ECU connector.





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

Standard Voltage:





Text in Illustration





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

9. RECONFIRM DTC

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

(b) Turn the ignition switch off.

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

Result





B -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

A -- REPLACE MASTER CYLINDER SOLENOID Disassembly

10. INSPECT STOP LP CTRL RELAY

(a) Remove the STOP LP CTRL relay from the engine room R/B No. 2.





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

Standard Resistance:





Text in Illustration





NG -- REPLACE STOP LP CTRL RELAY

OK -- GO TO LIGHTING SYSTEM (PROBLEM SYMPTOMS TABLE) Symptom Related Diagnostic Procedures