April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC C1A03: Driving Support ECU Internal Logical Error; DTC C1A06: Stop Light Switch Input Circuit: Procedure

CHECK FOR DTC
1. Using the Techstream, enter the following menus: Powertrain / Radar Cruise / Trouble Code.
2. Select "Clear" and clear the data.
3. Recheck for DTC.
  OK
  
  DTC C1A03 or C1A06 is not output.
NG → See step 2

OK → See step 3
REPLACE DRIVING SUPPORT ECU. Refer to REMOVAL
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING