DTC C1A4B: Stop Light Relay Circuit [04/2013 - 08/2015]: Procedure

1. Depress the brake pedal, push the engine switch and check that the engine starts.

   OK

   The engine starts.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO SFI SYSTEM 

for 2GR-FSE: Refer to PROBLEM SYMPTOMS TABLE [04/2013 - 08/2015]

for 4GR-FSE: Refer to PROBLEM SYMPTOMS TABLE [04/2013 - 08/2015]

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. Refer to  PROBLEM SYMPTOMS TABLE [04/2013 - 06/2014]  , or refer to  PROBLEM SYMPTOMS TABLE [06/2014 - 08/2015] 

Result: 

OK 

See step  3

1. Using a voltmeter, check the signal reading of the semiconductor PWR integration ECU.

   Refer to PROCEDURE - Step 1

   OK

   Output signal reading is normal.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

INSPECT SEMICONDUCTOR PWR INTEGRATION ECU (RESULTS OF SIGNAL READING CHECK). Refer to  PROCEDURE - Step 2 

Result: 

OK 

See step  4

1. Turn the engine switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Brake Actuator Assembly (Skid Control ECU))

2. Disconnect the A15 brake actuator assembly (skid control ECU) connector.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A15-31 (STPO) - Body ground	Always	11 to 14 V

4. Connect the A15 brake actuator assembly (skid control ECU) connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  8

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 [04/2013 - 10/2016]

   Chassis > ABS/VSC/TRAC > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Stop Light Relay	Stop light control relay (STOP LP)	ON or 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, read the Data List item Stop Light Relay Output.

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Stop Light Relay Output	Stop light control relay (STOP LP) output	ON or OFF	ON: Relay output on (Stop light on) OFF: Relay output off (Stop light 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  7

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 [04/2013 - 10/2016]

   Chassis > ABS/VSC/TRAC > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Stop Light Relay	Stop light control relay (STOP LP)	ON or 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 PWR integration ECU connector.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   2D-3 (ACC) - Body ground	Engine switch on (IG) (Active test OFF)	11 to 14 V
   2D-3 (ACC) - Body ground	Engine switch on (IG) (Active test ON)	Below 1.5 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SEMICONDUCTOR PWR INTEGRATION ECU. Refer to  REMOVAL [04/2013 - ] 

Result: 

NG 

REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU). Refer to  REMOVAL [04/2013 - 10/2016] 

1. Turn the engine switch off.
2. Disconnect the A15 brake actuator assembly (skid control ECU) connector.
3. Disconnect the 2F semiconductor PWR integration ECU connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A15-22 (STP2) - 2F-9 (OUT)	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU). Refer to  REMOVAL [04/2013 - 10/2016] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Turn the engine switch off.
2. Disconnect the A15 brake actuator assembly (skid control ECU) connector.
3. Disconnect the 2D semiconductor PWR integration ECU connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A15-31 (STPO) - 2D-3 (ACC)	Always	Below 1 Ω
   A15-31 (STPO) or 2D-3 (ACC) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SEMICONDUCTOR PWR INTEGRATION ECU. Refer to  REMOVAL [04/2013 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR