DTC C1A4B: Stop Light Relay Circuit [09/2017 - 05/2019]: Procedure
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) CONNECTOR)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-35 (STP) - Body ground Brake pedal depressed 11 to 14 V Brake pedal released Below 1.5 V A36-26 (STPO) - Body ground Engine switch on (IG) 11 to 14 V A36-5 (STP2) - Body ground Brake pedal depressed 11 to 14 V Brake pedal released Below 1.5 V - Connect the skid control ECU (brake actuator assembly) connector.
Result
Result Proceed to All terminal voltage is normal A Only STP terminal voltage abnormal B Only STPO terminal voltage abnormal C Only STP2 terminal voltage abnormal D STPO terminal and STP2 terminal voltage abnormal E
Result:
B
See step 5
Result:
C
See step 11
Result:
D
See step 12
Result:
E
See step 20
Result:
A
See step 2
- PERFORM ACTIVE TEST USING TECHSTREAM (STOP LIGHT RELAY)
- Turn the engine switch off.
- Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.
- Perform "Active Test" according to the display on the Techstream.
Refer to DATA LIST / ACTIVE TEST [10/2014 - 05/2019]
Chassis > ABS/VSC/TRAC > Active Test
Tester Display Measurement Item Control Range Diagnostic Note Stop Light Relay Stop light control ECU assembly ON or OFF Stop lights come on Chassis > ABS/VSC/TRAC > Active Test
Tester Display Stop Light Relay OK
Stop light turns ON/OFF in response to the Techstream operation
Result
Proceed to OK NG
Result:
NG
See step 4
Result:
OK
See step 3
- CHECK FOR DTC
- Clear the DTCs.
Refer to DTC CHECK / CLEAR [09/2017 - 05/2019]
Body Electrical > Pre-Collision 2 > Clear DTCs
- Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.
- Perform "Active Test" according to the display on the Techstream.
Refer to DATA LIST / ACTIVE TEST [10/2014 - 05/2019]
Chassis > ABS/VSC/TRAC > Active Test
Tester Display Measurement Item Control Range Diagnostic Note Stop Light Relay Stop light control ECU assembly ON or OFF Stop lights come on Chassis > ABS/VSC/TRAC > Active Test
Tester Display Stop Light Relay - Check for DTCs.
Refer to DTC CHECK / CLEAR [09/2017 - 05/2019]
Body Electrical > Pre-Collision 2 > Trouble Codes
Result
Result Proceed to DTC C1A4B is output. A DTC C1A4B is not output. B
Result:
A
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2017 - 05/2019]
Result:
B
REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY). Refer to REMOVAL [10/2014 - 05/2019]
- Clear the DTCs.
- INSPECT SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)
- Enter the following menus: Chassis / ABS/VSC/TRAC / Active Test.
- Perform "Active Test" according to the display on the Techstream.
Chassis > ABS/VSC/TRAC > Active Test
Tester Display Measurement Item Control Range Diagnostic Note Stop Light Relay Stop light control ECU assembly ON or OFF Stop lights come on Chassis > ABS/VSC/TRAC > Active Test
Tester Display Stop Light Relay - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A3-9 (ACC) - Body ground Active Test is ON Below 1.5 V *a Component with harness connected (Stop Light Switch Assembly) Result
Proceed to OK NG
Result:
OK
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to REMOVAL [10/2014 - ]
Result:
NG
REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY). Refer to REMOVAL [10/2014 - 05/2019]
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - ECM)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the A35 ECM connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-35 (STP) - Body ground Brake pedal depressed 8 to 14 V A36-35 (STP) - Body ground Brake pedal released Below 1.5 V - Connect the A35 ECM connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE ECM. Refer to REMOVAL [10/2014 - 05/2019]
Result:
NG
See step 6
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - SHIFT LOCK CONTROL UNIT ASSEMBLY)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the A35 ECM connector.
- Disconnect the I22 shift lock control unit assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-35 (STP) - Body ground Brake pedal depressed 8 to 14 V A36-35 (STP) - Body ground Brake pedal released Below 1.5 V - Connect the I22 shift lock control unit assembly connector.
- Connect the A35 ECM connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE SHIFT LOCK CONTROL UNIT ASSEMBLY. Refer to DISASSEMBLY [10/2014 - ]
Result:
NG
See step 7
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the A35 ECM connector.
- Disconnect the I22 shift lock control unit assembly connector.
- Disconnect the I51 certification ECU (smart key ECU assembly) connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-35 (STP) - Body ground Brake pedal depressed 8 to 14 V A36-35 (STP) - Body ground Brake pedal released Below 1.5 V - Connect the I51 certification ECU (smart key ECU assembly) connector.
- Connect the I22 shift lock control unit assembly connector.
- Connect the A35 ECM connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
Result:
NG
See step 8
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the A35 ECM connector.
- Disconnect the I22 shift lock control unit assembly connector.
- Disconnect the I51 certification ECU (smart key ECU assembly) connector.
- Disconnect the A3 stop light control ECU assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-35 (STP) - Body ground Brake pedal depressed 8 to 14 V A36-35 (STP) - Body ground Brake pedal released Below 1.5 V - Connect the A3 stop light control ECU assembly connector.
- Connect the I51 certification ECU (smart key ECU assembly) connector.
- Connect the I22 shift lock control unit assembly connector.
- Connect the A35 ECM connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to REMOVAL [10/2014 - ]
Result:
NG
See step 9
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the A35 ECM connector.
- Disconnect the I22 shift lock control unit assembly connector.
- Disconnect the I51 certification ECU (smart key ECU assembly) connector.
- Disconnect the A3 stop light control ECU assembly connector.
- Disconnect the A1 stop light switch assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-35 (STP) - Body ground Always Below 1.5 V - Connect the A1 stop light switch assembly connector.
- Connect the A3 stop light control ECU assembly connector.
- Connect the I51 certification ECU (smart key ECU assembly) connector.
- Connect the I22 shift lock control unit assembly connector.
- Connect the A35 ECM connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 10
- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT SWITCH ASSEMBLY)
- Turn the engine switch off.
- Disconnect the A36 skid control ECU (brake actuator assembly) connector.
- Disconnect the A1 stop light switch assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A36-35 (STP) - A1-2 (L) Always Below 1 Ω A36-35 (STP) or A1-2 (L) - Body ground Always 10 kΩ or higher - Connect the A1 stop light switch assembly connector.
- Connect the A36 skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to REMOVAL [09/2016 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
- Turn the engine switch off.
- Disconnect the A36 skid control ECU (brake actuator assembly) connector.
- Disconnect the A3 stop light control ECU assemblyconnector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A36-26 (STPO) - A3-9 (ACC) Always Below 1 Ω - Connect the A3 stop light control ECU assemblyconnector.
- Connect the A36 skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to REMOVAL [10/2014 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY LH)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the Q16 rear combination light assembly LH connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V - Connect the Q16 rear combination light assembly LH connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE REAR COMBINATION LIGHT ASSEMBLY LH. Refer to REMOVAL [09/2017 - ]
Result:
NG
See step 13
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR COMBINATION LIGHT ASSEMBLY RH)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the Q16 rear combination light assembly LH connector.
- Disconnect the P13 rear combination light assembly RH connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V - Connect the P13 rear combination light assembly RH connector.
- Connect the Q16 rear combination light assembly LH connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE REAR COMBINATION LIGHT ASSEMBLY RH. Refer to REMOVAL [09/2017 - ]
Result:
NG
See step 14
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR LIGHT ASSEMBLY LH)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the Q16 rear combination light assembly LH connector.
- Disconnect the P13 rear combination light assembly RH connector.
- Disconnect the Y11 rear light assembly LH connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V - Connect the Y11 rear light assembly LH connector.
- Connect the P13 rear combination light assembly RH connector.
- Connect the Q16 rear combination light assembly LH connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE REAR LIGHT ASSEMBLY LH. Refer to REMOVAL [09/2017 - ]
Result:
NG
See step 15
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - REAR LIGHT ASSEMBLY RH)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the Q16 rear combination light assembly LH connector.
- Disconnect the P13 rear combination light assembly RH connector.
- Disconnect the Y11 rear light assembly LH connector.
- Disconnect the Y10 rear light assembly RH connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V - Connect the Y10 rear light assembly RH connector.
- Connect the Y11 rear light assembly LH connector.
- Connect the P13 rear combination light assembly RH connector.
- Connect the Q16 rear combination light assembly LH connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE REAR LIGHT ASSEMBLY RH. Refer to REMOVAL [09/2017 - ]
Result:
NG
See step 16
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - CENTER STOP LIGHT ASSEMBLY)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the Q16 rear combination light assembly LH connector.
- Disconnect the P13 rear combination light assembly RH connector.
- Disconnect the Y11 rear light assembly LH connector.
- Disconnect the Y10 rear light assembly RH connector.
- Disconnect the e1 center stop light assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-5 (STP2) - Body ground Brake pedal depressed 8 to 14 V A36-5 (STP2) - Body ground Brake pedal released Below 1.5 V - Connect the e1 center stop light assembly connector.
- Connect the Y10 rear light assembly RH connector.
- Connect the Y11 rear light assembly LH connector.
- Connect the P13 rear combination light assembly RH connector.
- Connect the Q16 rear combination light assembly LH connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE CENTER STOP LIGHT ASSEMBLY. Refer to REMOVAL [10/2014 - ]
Result:
NG
See step 17
- INSPECT TERMINAL VOLTAGE (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
- Turn the engine switch off.
- Disconnect the skid control ECU (brake actuator assembly) connector.
*a Front view of harness connector
(to Skid control ECU (brake actuator assembly)) - Disconnect the Q16 rear combination light assembly LH connector.
- Disconnect the P13 rear combination light assembly RH connector.
- Disconnect the Y11 rear light assembly LH connector.
- Disconnect the Y10 rear light assembly RH connector.
- Disconnect the e1 center stop light assembly connector.
- Disconnect the A3 stop light control ECU assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A36-5 (STP2) - Body ground Always Below 1.5 V - Connect the A3 stop light control ECU assembly connector.
- Connect the e1 center stop light assembly connector.
- Connect the Y10 rear light assembly RH connector.
- Connect the Y11 rear light assembly LH connector.
- Connect the P13 rear combination light assembly RH connector.
- Connect the Q16 rear combination light assembly LH connector.
- Connect the skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 18
- CHECK HARNESS AND CONNECTOR (+B/GND TERMINAL)
- Turn the engine switch off.
*a Front view of harness connector
(to Stop light control ECU assembly) - Disconnect the A3 stop light control ECU assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A3-6 (+B) - Body ground Always 11 to 14V - Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A3-8 (GND) - Body ground Always Below 1 Ω - Connect the A3 stop light control ECU assembly connector.
Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 19
- Turn the engine switch off.
- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
- Turn the engine switch off.
- Disconnect the A36 skid control ECU (brake actuator assembly) connector.
- Disconnect the A3 stop light control ECU assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A3-1 (OUT) - A36-5 (STP2) Always Below 1 Ω A3-1 (OUT) or A36-5 (STP2) - Body ground Always 10 kΩ or higher - Connect the A3 stop light control ECU assembly connector.
- Connect the A36 skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to REMOVAL [10/2014 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- CHECK HARNESS AND CONNECTOR (+B/GND TERMINAL)
- Turn the engine switch off.
*a Front view of harness connector
(to Stop light control ECU assembly) - Disconnect the A3 stop light control ECU assembly connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A3-6 (+B) - Body ground Always 11 to 14V - Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A3-8 (GND) - Body ground Always Below 1 Ω - Connect the A3 stop light control ECU assembly connector.
Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 21
- Turn the engine switch off.
- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - STOP LIGHT CONTROL ECU ASSEMBLY)
- Turn the engine switch off.
- Disconnect the A36 skid control ECU (brake actuator assembly) connector.
- Disconnect the A3 stop light control ECU assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A3-1 (OUT) - A36-5 (STP2) Always Below 1 Ω A3-1 (OUT) or A36-5 (STP2) - Body ground Always 10 kΩ or higher - Connect the A3 stop light control ECU assembly connector.
- Connect the A36 skid control ECU (brake actuator assembly) connector.
Result
Proceed to OK NG
Result:
OK
REPLACE STOP LIGHT CONTROL ECU ASSEMBLY. Refer to REMOVAL [09/2016 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR