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

HINT: 

Pre-collision system DTC C1A4B may be stored due to a malfunction in the vehicle stability control system. Therefore, it is necessary to check for and troubleshoot vehicle stability control system DTCs first.

1. Check for DTCs.
   • for Hydraulic Brake Booster: Refer to DTC CHECK / CLEAR [08/2019 - ]
   • for Vacuum Brake Booster: Refer to DTC CHECK / CLEAR [08/2019 - ]

   Result

   Result	Proceed to
   Vehicle stability control system DTCs are not output	A
   Vehicle stability control system DTCs are output(for Hydraulic Brake Booster)	B
   Vehicle stability control system DTCs are output(for Vacuum Brake Booster)	C

Result: 

B 

GO TO VEHICLE STABILITY CONTROL SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - ] 

Result: 

C 

GO TO VEHICLE STABILITY CONTROL SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - ] 

Result: 

A 

See step  2

1. Clear the DTCs.

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

2. Make sure that the DTC detection conditions are met.

   HINT: 

   If the detection conditions are not met, the system cannot detect the malfunction.

3. Check for DTCs.

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

   Result

   Result	Proceed to
   DTC C1A4B is not output	A
   DTC C1A4B is output	B

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - ] 

Result: 

B 

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  REMOVAL [08/2019 - 08/2021]  , or refer to  REMOVAL [08/2021 - ]