DTC C1380/64: Stop Light Control Relay Malfunction: Procedure

1. Check that the stop lights come on when the brake pedal is depressed and go off when the brake pedal is released.

   OK

   Condition	Illumination Condition
   Brake pedal depressed	ON
   Brake pedal released	OFF

NG → See step   11 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Select the Data List on the Techstream. Refer to DATA LIST / ACTIVE TEST .
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Stop Light SW	Stop light switch / ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-

4. 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 → See step   8 

OK: Go to next step 

1. Select the Active Test on the Techstream. Refer to DATA LIST / ACTIVE TEST .
   ABS/VSC/TRAC
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Stop Light Relay	Stop light control relay	Relay ON/OFF	Stop lights come on

2. Perform the Active Test of the stop light control relay using the Techstream.
3. Select the Data List on the Techstream. Refer to DATA LIST / ACTIVE TEST .
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Stop Light Relay Output	Stop light control relay output / ON or OFF	ON: Relay output on OFF: Relay output off	-

4. Check for stop light control relay operation using Data List and stop light operation by performing an Active Test.

   Result

   Result	Proceed to
   Data List content and stop light operation are normal	A
   Data List content is normal but stop lights do not turn on or off	B

B → See step   6 

A: Go to next step 

1. Turn the power switch off.
   Fig 1: Identifying Skid Control ECU (STP2 Terminal)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
3. Disconnect the skid control ECU connector.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A58-6 (STP2) - Body ground	Stop light switch ON (Brake pedal depressed)	11 to 14 V
   A58-6 (STP2) - Body ground	Stop light switch OFF (Brake pedal released)	Below 1.5 V

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Skid Control ECU)

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

OK: Go to next step 

1. Reconnect the skid control ECU connector.
2. Clear the DTCs. Refer to DTC CHECK / CLEAR .
3. Turn the power switch on (READY).
4. Perform a road test.
5. Check if the same DTC is recorded. Refer to DTC CHECK / CLEAR .

   Result

   Result	Proceed to
   DTC (C1380/64) is not output	A
   DTC (C1380/64) is output	B

B → See step   10 

A → See step   9 

1. Inspect the stop light control relay. Refer to INSPECTION .

   OK

   The stop light control relay is normal.

NG → See step   12 

OK: Go to next step 

1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
   Fig 2: Identifying Skid Control ECU Connector And Stop Light Control Relay Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the skid control ECU connector and the stop light control relay connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A58-3 (STP0) - A28-9 (ACC)	Always	Below 1 Ω
   A58-3 (STP0) - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Skid Control ECU)
   *2	Front view of wire harness connector (to Stop Light Control Relay)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   10 

1. Turn the power switch off.
   Fig 3: Identifying Skid Control ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
3. Disconnect the skid control ECU connector.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A58-33 (STP) - Body ground	Stop light switch ON (Brake pedal depressed)	11 to 14 V
   A58-33 (STP) - Body ground	Stop light switch OFF (Brake pedal released)	Below 1.5 V

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Skid Control ECU)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT) 

OK → See step   10