C1380

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

DESCRIPTION

Upon receiving the hill-start assist control operating signal from the skid control ECU, the relay contact turns on and the stop light comes on.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
- When replacing the master cylinder solenoid, perform calibration Programming and Relearning.
- 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 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 -- CHECK TERMINAL VOLTAGE AND RESISTANCE (+B, GND)
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (STOP LIGHT SW)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

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

ABS/VSC/TRAC

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

OK:

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

NG -- CHECK TERMINAL VOLTAGE (STP)
OK -- Continue to next step.

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

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

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

ABS/VSC/TRAC

(f) While performing the Active Test, check the illumination condition of the stop lights and "Stop Light Relay Output" in the Data List.

ABS/VSC/TRAC

Result

B -- INSPECT STOP LP RELAY
A -- Continue to next step.

4. CHECK TERMINAL VOLTAGE (STP2)

(a) Disconnect the A7 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
OK -- Continue to next step.

5. RECONFIRM DTC

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

(b) Start the engine.

(c) Perform a road test.

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

Result

B -- REPLACE MASTER CYLINDER SOLENOID Disassembly

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

6. CHECK TERMINAL VOLTAGE AND RESISTANCE (+B, GND)

(a) Disconnect the A6 stop light control relay 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
OK -- Continue to next step.

7. CHECK TERMINAL VOLTAGE (STP)

(a) Disconnect the A6 stop light control relay 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
OK -- Continue to next step.

8. INSPECT STOP LP RELAY

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

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

Standard Resistance:

Text in Illustration

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

9. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY - STOP LP RELAY)

(a) Disconnect the A6 stop light control relay connector.

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

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

Standard Resistance:

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

10. CHECK TERMINAL VOLTAGE (STOP LIGHT POWER SOURCE TERMINAL)

(a) Remove the STOP LP 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 -- REPLACE STOP LIGHT CONTROL RELAY ASSEMBLY Removal

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK STOP LP RELAY TERMINAL 3 CIRCUIT)

11. CHECK TERMINAL VOLTAGE (STP)

(a) Disconnect the A7 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

OK -- REPLACE MASTER CYLINDER SOLENOID Disassembly

12. INSPECT STOP LP RELAY

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

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

Standard Resistance:

Text in Illustration

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

13. CHECK TERMINAL VOLTAGE (STOP LP RELAY POWER SOURCE TERMINAL)

(a) Remove the STOP LP 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.

14. CHECK TERMINAL VOLTAGE (STPO)

(a) Disconnect the A7 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
OK -- Continue to next step.

15. RECONFIRM DTC

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

(b) Turn the engine 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