Stop Light Control Relay Malfunction - Electronically Controlled Brake System

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1380/64: Stop Light Control Relay Malfunction

DTC C1380/64 - 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
NOTE: When replacing the skid control ECU, perform initialization and calibration of the linear solenoid valve. Initialization
HINT: When C1249/49 is output together with C1380/64, inspect and repair the trouble areas indicated by C1249/49 first C1249.

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
OK -- Continue to next step.
2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(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 (STP TERMINAL)
OK -- Continue to next step.
3. INSPECT SKID CONTROL ECU (EXI TERMINAL)





(a) Turn the power switch off.
(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(c) Disconnect the skid control ECU connectors.
(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (EXI CIRCUIT)
OK -- Continue to next step.
4. PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT CONTROL RELAY)
(a) Reconnect the skid control ECU connectors.
(b) Connect the Techstream to the DLC3.
(c) Turn the power switch on (IG).
(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
OK -- Continue to next step.
5. RECONFIRM DTC
(a) Turn the power switch off.
(b) Clear the DTCs.
(c) Turn the power switch on (READY).
(d) Perform a road test.
(e) Check if the same DTC is recorded.
Result:






B -- REPLACE SKID CONTROL ECU
A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)
6. INSPECT STOP LIGHT CONTROL RELAY





(a) Turn the power switch off.
(b) Remove the stop light control relay.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE STOP LIGHT CONTROL RELAY
OK -- Continue to next step.
7. INSPECT ENGINE ROOM 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 (CR TERMINAL)





(a) Install the stop light control relay.
(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.
(c) Disconnect the skid control ECU connector.
(d) Turn the power switch on (IG).
(e) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (CR CIRCUIT)
OK -- REPLACE SKID CONTROL ECU
9. INSPECT SKID CONTROL ECU (STP TERMINAL)





(a) Turn the power switch off.
(b) Make sure that there is no looseness at the locking part and the 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 -- REPLACE SKID CONTROL ECU