2016 Lexus GS FFACTORY OEM SERVICE PROCEDURE

Lane-Keeping Assist System

LANE-KEEPING ASSIST SYSTEM DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION

DTC Code Description
C1A01 Driving Support ECU
C1A10 Front Radar Sensor
C1A11 Front Radar Sensor Incorrect Axial Gap
C1A14 Front Radar Sensor Beam Axis Not Adjusted
C1A47 Steering Angle Sensor
C1A48 G Sensor
C1A50 Brake System Malfunction
C1A70 Power Steering Control System
C1A71 Power Steering Control Torque
C1A72 Communication Error from FCM to Driving Support ECU
C1A73 Driving Support ECU Receive Data Malfunction
C1A74 Steering Vibrator System Malfunction
C1A75 Lost Communication with Steering Vibrator System
C1AA0 Front Camera Module Circuit
C1AA1 FCM Destination Information Unmatched
C1AA2 Vehicle Speed Tolerance Malfunction
C1AA3 Vehicle Speed Sensor Circuit
C1AA4 Yaw Rate Sensor Circuit
C1AA5 Yaw Rate Sensor Power Supply Voltage Circuit
C1AA6 Yaw Rate Sensor Zero Point Malfunction
C1AA9 Front Camera Module Beam Axis Not Adjusted
C1AAA FCM Destination Information Uninitialized
C1AAC Vehicle Information Unmatched
C1AAD Vehicle Information Initialization Incomplete
U0100 Lost Communication With ECM/PCM "A"
U0101 Lost Communication With TCM
U0123 Lost Communication with Yaw Rate Sensor Module
U0126 Lost Communication with Steering Angle Sensor Module
U0129 Lost Communication with Brake System Control Module
U0131 Lost Communication with Power Steering Control Module
U0142 Lost Communication with Body Control Module "B"
U0155 Lost Communication with Combination Meter
U0235 Lost Communication with Cruise Control Front Distance Range Sensor
U023A Lost Communication with Front Camera Module
U1104 Lost Communication with Driving Support ECU
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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