DTC C1A4B: Stop Light Relay Circuit [10/2014 - 10/2015]: Procedure
- CHECK DTC OUTPUT (ELECTRONICALLY CONTROLLED BRAKE SYSTEM)
- Check for electronically controlled brake system DTCs (Refer to DTC CHECK / CLEAR [10/2014 - ]
).
OK
Electronically controlled brake system DTCs are not output.
Result:
NG
GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM
(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 10/2015] )
Result:
OK
See step 2
- Check for electronically controlled brake system DTCs (Refer to DTC CHECK / CLEAR [10/2014 - ]
).
- 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
Condition Illumination Condition Brake pedal depressed. ON Brake pedal released. OFF
Result:
NG
INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT)
(Refer to PROBLEM SYMPTOMS TABLE [10/2014 - 10/2015] )
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 SWITCH ASSEMBLY
- Check the stop light switch assembly (Refer to ON-VEHICLE INSPECTION [10/2014 - ]
).
OK
The stop light switch assembly is normal.
Result:
NG
REPLACE STOP LIGHT SWITCH ASSEMBLY
(Refer to COMPONENTS [10/2014 - ] )
Result:
OK
See step 4
- Check the stop light switch assembly (Refer to ON-VEHICLE INSPECTION [10/2014 - ]
).
- CHECK HARNESS AND CONNECTOR (STP2 TERMINAL)
- Turn the power switch off.
- Disconnect the A51 skid control ECU (brake booster with master cylinder assembly) connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A51-6 (STP2) - Body ground Stop light switch assembly ON (Brake pedal depressed) 11 to 14 V A51-6 (STP2) - Body ground Stop light switch assembly OFF (Brake pedal released) Below 1.5 V - Reconnect the A51 skid control ECU (brake booster with master cylinder assembly) connector.
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (STP2 CIRCUIT)
Result:
OK
See step 5
- PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT RELAY)
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.
- Select the Active Test on the Techstream (Refer to DATA LIST / ACTIVE TEST [10/2014 - 10/2015]
).ABS/VSC/TRAC
Tester Display Test Part Control Range Diagnostic Note Stop Light Relay Stop light control relay (Stop light switch assembly) Relay ON/OFF Stop lights come on - Perform the Active Test of the stop light control relay (stop light switch assembly) using the Techstream.
- Select the Data List on the Techstream (Refer to DATA LIST / ACTIVE TEST [10/2014 - 10/2015]
).ABS/VSC/TRAC
Tester Display Measurement Item/Range Normal Condition Diagnostic Note Stop Light Relay Output Stop light control relay (Stop light switch assembly) output / ON or OFF ON: Relay output on
OFF: Relay output off- - Check for stop light switch assembly operation using the Data List and stop light operation by performing an Active Test.
Result
Result Proceed to Data List content and stop light operation are abnormal or Data List content is normal but stop lights do not turn on or off. A Data List content and stop light operation are normal. B
Result:
B
See step 7
Result:
A
See step 6
- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU)
- Turn the power switch off.
- Disconnect the A22 stop light switch assembly connector.
- Disconnect the A51 skid control ECU (brake booster with master cylinder assembly) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A22-4 (ACC) - A51-3 (STPO) Always Below 1 Ω A22-4 (ACC) or A51-3 (STPO) - Body ground Always 10 kΩ or higher
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 7
- CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU)
- Turn the power switch off.
- Disconnect the A22 stop light switch assembly connector.
- Disconnect the A51 skid control ECU (brake booster with master cylinder assembly) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A22-1 (OUT) - A51-33 (STP) Always Below 1 Ω - Reconnect the A51 skid control ECU (brake booster with master cylinder assembly) connector.
- Reconnect the A22 stop light switch assembly connector.
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 8
- CHECK HARNESS AND CONNECTOR (STP TERMINAL)
- Turn the power switch off.
- Make sure that there is no looseness at the locking part and the connecting part of the connector.
- Disconnect the A51 skid control ECU (brake booster with master cylinder assembly) connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A51-33 (STP) - Body ground Stop light switch ON (Brake pedal depressed) 11 to 14 V A51-33 (STP) - Body ground Stop light switch OFF (Brake pedal released) Below 1.5 V - Reconnect the A51 skid control ECU (brake booster with master cylinder assembly) connector.
Result:
NG
REPLACE STOP LIGHT SWITCH ASSEMBLY
(Refer to COMPONENTS [10/2014 - ] )
Result:
OK
See step 9
- CHECK DTC OUTPUT (DTC C1A4B)
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Body Electrical / Pre-Collision 2 / Trouble Codes.
- Clear the DTCs (Refer to DTC CHECK / CLEAR [10/2014 - 10/2015] ).
- Select the Active Test on the Techstream (Refer to DATA LIST / ACTIVE TEST [10/2014 - 10/2015]
).ABS/VSC/TRAC
Tester Display Test Part Control Range Diagnostic Note Stop Light Relay Stop light control relay (Stop light switch assembly) Relay ON/OFF Stop lights come on - Perform the Active Test of the stop light control relay (stop light switch assembly) using the Techstream.
- Select the Data List on the Techstream (Refer to DATA LIST / ACTIVE TEST [10/2014 - 10/2015]
).ABS/VSC/TRAC
Tester Display Measurement Item/Range Normal Condition Diagnostic Note Stop Light Relay Output Stop light control relay (Stop light switch assembly) output / ON or OFF ON: Relay output on
OFF: Relay output off- - Check for stop light switch assembly operation using the Data List and stop light operation by performing an Active Test.
- Recheck for DTCs.
OK
DTC C1A4B is not output.
Result:
OK
END
Result:
NG
REPLACE DRIVING SUPPORT ECU ASSEMBLY
(Refer to COMPONENTS [10/2014 - 10/2015] )