DTC C1A4B: Stop Light Relay Circuit [11/2015 - 12/2018]: Procedure
- INSPECT HYBRID SYSTEM START
- 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
- for NICKEL METAL HYDRIDE BATTERY: Refer to PROBLEM SYMPTOMS TABLE [11/2015 - 11/2017] , or refer to PROBLEM SYMPTOMS TABLE [11/2017 - 12/2018]
- for LITHIUM-ION BATTERY: Refer to PROBLEM SYMPTOMS TABLE [11/2015 - 12/2018]
Result:
OK
See step 2
- Depress the brake pedal, push the power switch and check that the power switch turns on (READY).
- CHECK STOP LIGHT OPERATION
- 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 HOW TO PROCEED WITH TROUBLESHOOTING [11/2015 - 07/2020]
Result:
OK
See step 3
- Check that the stop lights come on when the brake pedal is depressed and go off when the brake pedal is released.
- INSPECT STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY)
- Turn the power switch off.
- Inspect the stop light relay (stop light switch assembly).
Refer to ON-VEHICLE INSPECTION [11/2015 - 12/2018]
OK
The stop light relay (stop light switch assembly) is normal.
Result
Proceed to OK NG
Result:
NG
REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to COMPONENTS [11/2015 - ]
Result:
OK
See step 4
- CHECK FOR DTCs (ELECTRONICALLY CONTROLLED BRAKE SYSTEM)
- Check for DTCs.
Chassis > ABS/VSC/TRAC > Trouble Codes
Result
Result Proceed to DTCs are not output A DTCs are output B
Result:
B
GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2015 - 12/2018]
Result:
A
See step 5
- Check for DTCs.
- CHECK HARNESS AND CONNECTOR (STPO TERMINAL VOLTAGE)
- Turn the power switch off.
- Disconnect the A41 skid control ECU (brake booster with master cylinder assembly) connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
(A41)
(A41)
Tester Connection Condition Specified Condition A41-22 (STPO) - Body ground Always 11 to 14 V - Connect the A41 skid control ECU (brake booster with master cylinder assembly) connector.
Result
Proceed to OK NG
Result:
NG
See step 10
Result:
OK
See step 6
- PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT RELAY)
- According to the display on the Techstream, perform the Active Test Stop Light Relay.
Chassis > ABS/VSC/TRAC > Active Test
Tester Display Measurement Item Control Range Diagnostic Note Stop Light Relay Stop light control relay (Stop light switch assembly) ON / OFF Test possible at vehicle speed of 0 km/h (0 mph) Chassis > ABS/VSC/TRAC > Active Test
Active Test Display Stop Light Relay Data List Display Stop Light Relay Output - According to the display on the Techstream, perform the Data List 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 light switch assembly)
(STPO terminal output)ON or OFF ON: Output
OFF: Not output- - 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 9
Result:
A
See step 7
- According to the display on the Techstream, perform the Active Test Stop Light Relay.
- INSPECT SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY)
- According to the display on the Techstream, perform the Active Test Stop Light Relay.
Chassis > ABS/VSC/TRAC > Active Test
Tester Display Measurement Item Control Range Diagnostic Note Stop Light Relay Stop light control relay (Stop light switch assembly) ON / OFF Test possible at vehicle speed of 0 km/h (0 mph) Chassis > ABS/VSC/TRAC > Active Test
Tester Display Stop Light Relay - Measure the voltage according to the value(s) in the table below.
HINT:
Do not disconnect the stop light relay (stop light switch assembly) connector.
Standard Voltage
(A47)
(A47)
Tester Connection Condition Specified Condition A47-4 (ACC) - Body ground Power switch on (IG)
(Active test ON)Below 1.5 V Result
Proceed to OK NG
Result:
NG
REPLACE SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY). Refer to COMPONENTS [11/2015 - ]
Result:
OK
See step 8
- According to the display on the Techstream, perform the Active Test Stop Light Relay.
- INSPECT SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY)
- According to the display on the Techstream, perform the Active Test Stop Light Relay.
Chassis > ABS/VSC/TRAC > Active Test
Tester Display Measurement Item Control Range Diagnostic Note Stop Light Relay Stop light control relay (Stop light switch assembly) ON / OFF Test possible at vehicle speed of 0 km/h (0 mph) Chassis > ABS/VSC/TRAC > Active Test
Tester Display Stop Light Relay - Measure the voltage according to the value(s) in the table below.
HINT:
Do not disconnect the stop light relay (stop light switch assembly) connector.
Standard Voltage
(A47)
(A47)
Tester Connection Condition Specified Condition A47-4 (ACC) - Body ground Power switch on (IG)
(Active test OFF)11 to 14 V Result
Proceed to OK NG
Result:
OK
REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to COMPONENTS [11/2015 - ]
Result:
NG
REPLACE SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY). Refer to COMPONENTS [11/2015 - ]
- According to the display on the Techstream, perform the Active Test Stop Light Relay.
- CHECK HARNESS AND CONNECTOR (STOP LIGHT RELAY - SKID CONTROL ECU)
- Turn the power switch off.
- Disconnect the A47 stop light relay (stop light switch assembly) connector.
- Disconnect the A41 skid control ECU (brake booster with master cylinder assembly) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
(A47)
(A41)
(A47)
(A41)
Tester Connection Condition Specified Condition A47-1 (OUT) - A41-12 (STP) Always Below 1 Ω - Connect the A41 skid control ECU (brake booster with master cylinder assembly) connector.
- Connect the A47 stop light relay (stop light switch assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE SKID CONTROL ECU (BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY). Refer to COMPONENTS [11/2015 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- CHECK HARNESS AND CONNECTOR (STOP LIGHT RELAY - SKID CONTROL ECU)
- Turn the power switch off.
- Disconnect the A47 stop light relay (stop light switch assembly) connector.
- Disconnect the A41 skid control ECU (brake booster with master cylinder assembly) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
(A47)
(A41)
(A47)
(A41)
Tester Connection Condition Specified Condition A47-4 (ACC) - A41-22 (STPO) Always Below 1 Ω A47-4 (ACC) or A41-22 (STPO) - Body ground Always 10 kΩ or higher - Connect the A41 skid control ECU (brake booster with master cylinder assembly) connector.
- Connect the A47 stop light relay (stop light switch assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE STOP LIGHT RELAY (STOP LIGHT SWITCH ASSEMBLY). Refer to COMPONENTS [11/2015 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR