C1380

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1380/64: Stop Light Control Relay Malfunction

DTC C1380/64 - Stop Light Control Relay Malfunction

DESCRIPTION

Upon receiving the hill-start assist control or the dynamic radar cruise control (for vehicles with the dynamic radar cruise 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 skid control ECU, perform zero point calibration and store system information Testing and Inspection.
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 engine 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 (STP1 TERMINAL)
OK -- Continue to next step.
3. INSPECT SKID CONTROL ECU (STP2 TERMINAL)

(a) Turn the engine 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 (STP2 CIRCUIT)
OK -- Continue to next step.
4. PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT CONTROL (BRK-LP) RELAY)
(a) Reconnect the skid control ECU connector.
(b) Connect the Techstream to the DLC3.
(c) Turn the engine 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 (BRK-LP)
OK -- Continue to next step.
5. RECONFIRM DTC
(a) Turn the engine switch off.
(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(c) Turn the engine switch on (IG).
(d) Perform a road test.
(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
Result:

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

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

NG -- REPLACE STOP LIGHT CONTROL RELAY (BRK-LP)
OK -- Continue to next step.
7. INSPECT ENGINE ROOM NO. 3 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 (BRK-LP) 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 engine 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 (STPO CIRCUIT)
OK -- REPLACE SKID CONTROL ECU
9. INSPECT SKID CONTROL ECU (STP1 TERMINAL)

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STP1 CIRCUIT)
OK -- REPLACE SKID CONTROL ECU