DTC C1A4B: Stop Light Relay Circuit [08/2018 - 08/2019]: Procedure

1. Depress the brake pedal, push the power switch and check that the power switch turns on (READY).

   OK

   The power switch turns on (READY).

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO HYBRID CONTROL SYSTEM. Refer to  PROBLEM SYMPTOMS TABLE [12/2017 - ] 

Result: 

OK 

See step  2

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

   OK

   The stop lights illuminate when the brake pedal is depressed. The stop lights turn off when the brake pedal is released.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO LIGHTING SYSTEM 

• w/ Automatic Headlight Beam Level Control System: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - 08/2019]
• w/o Automatic Headlight Beam Level Control System: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - 08/2019]

Result: 

OK 

See step  3

1. Turn the power switch off.
2. Inspect the semiconductor power integration ECU.

   Refer to ON-VEHICLE INSPECTION [10/2015 - ]

   OK

   The semiconductor power integration ECU is normal.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  9

Result: 

OK 

See step  4

1. Turn the power switch off.
2. Disconnect the A62 skid control ECU assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Skid control ECU assembly)

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A62-4 (STPO) - Body ground	Always	11 to 14 V

4. Connect the A62 skid control ECU assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  14

Result: 

OK 

See step  5

1. According to the display on the Techstream, perform the Active Test Stop Light Relay.

   Refer to DATA LIST / ACTIVE TEST [08/2018 - 08/2019]

   Chassis > ABS/VSC/TRAC > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Stop Light Relay	Semiconductor PWR integration ECU	ECU (Stop light output) ON/OFF	Stop lights come on

   Chassis > ABS/VSC/TRAC > Active Test 

   Active Test Display
   Stop Light Relay

   Data List Display
   Stop Light Relay Output

2. According to the display on the Techstream, perform the Data List Stop Light Relay.

   Refer to DATA LIST / ACTIVE TEST [08/2018 - 08/2019]

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Stop Light Relay Output	Semiconductor PWR integration ECU (STPO terminal output)	ON or OFF	ON: Output on OFF: Output off	-

3. Check that the Data List item Stop Light Relay Output changes between ON and OFF and the stop lights turn on and off according to the operation of the Active Test.

   Result

   Result	Proceed to
   The Data List item Stop Light Relay Output does not change between ON and OFF and the stop lights do not turn ON and OFF according to the operation of the Active Test.	A
   The Data List item Stop Light Relay Output changes between ON and OFF but the stop lights do not turn ON and OFF according to the operation of the Active Test.	B

Result: 

B 

See step  11

Result: 

A 

See step  6

1. According to the display on the Techstream, perform the Active Test Stop Light Relay.

   Refer to DATA LIST / ACTIVE TEST [08/2018 - 08/2019]

   Chassis > ABS/VSC/TRAC > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Stop Light Relay	Semiconductor PWR integration ECU	ECU (Stop light output) ON/OFF	Stop lights come on

   Chassis > ABS/VSC/TRAC > Active Test 

   Tester Display
   Stop Light Relay

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

   HINT: 

   Do not disconnect the semiconductor power integration ECU connector.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   1D-3 (ACC) - Body ground	Power switch on (IG) (Active test OFF)	11 to 14 V
   	Power switch on (IG) (Active test ON)	Below 1.5 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  10

Result: 

OK 

See step  7

1. Replace the semiconductor power integration ECU.

   Refer to COMPONENTS [03/2018 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  8

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [08/2018 - 08/2019]

   Chassis > ABS/VSC/TRAC > Clear DTCs 

2. According to the display on the Techstream, perform the Active Test Stop Light Relay.

   Refer to DATA LIST / ACTIVE TEST [08/2018 - 08/2019]

   Chassis > ABS/VSC/TRAC > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Stop Light Relay	Semiconductor PWR integration ECU	ECU (Stop light output) ON/OFF	Stop lights come on

   Chassis > ABS/VSC/TRAC > Active Test 

   Tester Display
   Stop Light Relay

3. Check for DTCs.

   Refer to DTC CHECK / CLEAR [08/2018 - 08/2019]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   Result

   Result	Proceed to
   DTC C1380 is not output	A
   DTC C1380 is output	B

Result: 

A 

END 

Result: 

B 

GO TO DTC CHART (C1380). Refer to  DTC C1380-64: Stop Light Control Relay Malfunction [08/2018 - 08/2019] 

1. Replace the semiconductor power integration ECU.

   Refer to COMPONENTS [03/2018 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  8

1. Replace the skid control ECU assembly.

   Refer to REMOVAL [03/2018 - 08/2019]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  8

1. Turn the power switch off.
2. Remove the semiconductor power integration ECU.
3. Disconnect the A61 skid control ECU assembly connector.
4. Measure the resistance according to the value (s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1F-9 (OUT) - A61-14 (STP2)	Always	Below 1 Ω

5. Connect the A61 skid control ECU assembly connector.
6. Install the semiconductor power integration ECU.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  13

Result: 

OK 

See step  12

1. Replace the skid control ECU assembly.

   Refer to REMOVAL [03/2018 - 08/2019]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  8

1. Repair or replace the harness or connector.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  8

1. Turn the power switch off.
2. Remove the semiconductor power integration ECU.
3. Disconnect the A62 skid control ECU assembly connector.
4. Measure the resistance according to the value (s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1D-3 (ACC) - A62-4 (STPO)	Always	Below 1 Ω
   1D-3 (ACC) or A62-4 (STPO) - Body ground	Always	10 kΩ or higher

5. Connect the A62 skid control ECU assembly connector.
6. Install the semiconductor power integration ECU.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  16

Result: 

OK 

See step  15

1. Replace the semiconductor power integration ECU.

   Refer to COMPONENTS [03/2018 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  8

1. Repair or replace the harness or connector.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  8