C1380

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

DESCRIPTION

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





WIRING DIAGRAM

Refer to DTC C1425 C1425.

INSPECTION PROCEDURE

NOTICE:
When replacing the brake actuator assembly, perform zero point calibration Component Tests and General Diagnostics.

HINT
When C1425 is output together with C1380, inspect and repair the trouble areas indicated by 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 -- INSPECT STOP LIGHT CIRCUIT Stop Light Switch Circuit
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 condition observed on the Techstream changes according to brake pedal operation.

OK:

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

NG -- INSPECT SKID CONTROL ECU (STP2 TERMINAL)
OK -- Continue to next step.

3. INSPECT SKID CONTROL ECU (STP TERMINAL)

(a) Turn the ignition switch off.





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

(c) Disconnect the skid control ECU connector.

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

Standard Voltage:





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

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

(a) Reconnect the skid control ECU connector.

(b) Connect the Techstream to the DLC3.

(c) Start the engine.

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

ABS/VSC/TRAC:





(e) Check that the "ON" and "OFF" of the stop lights can be shown on the rear combination light by the Techstream.

OK:

The stop lights turn on or off in accordance with the Techstream.

NG -- INSPECT STOP LIGHT CONTROL RELAY (BRK)
OK -- Continue to next step.

5. RECONFIRM DTC

(a) Turn the ignition switch off.

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

(c) Start the engine.

(d) Perform a road test.

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

Result:





B -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

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

6. INSPECT STOP LIGHT CONTROL RELAY (BRK)

(a) Turn the ignition switch off.





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

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

Standard Resistance:





NG -- REPLACE STOP LIGHT CONTROL RELAY (BRK)
OK -- Continue to next step.

7. INSPECT ENGINE ROOM NO. 1 RELAY BLOCK (POWER SOURCE TERMINAL)

(a) 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.

8. INSPECT SKID CONTROL ECU (STPO TERMINAL)

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





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

(c) Disconnect the skid control ECU connector.

(d) Turn the ignition switch to ON.

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

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STPO CIRCUIT)

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

9. INSPECT SKID CONTROL ECU (STP2 TERMINAL)

(a) Turn the ignition switch off.





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

(c) Disconnect the skid control ECU connector.

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

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP2 CIRCUIT)

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal