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Home >> Lexus >> 2019 >> LC 500 >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Cruise Control Systems >> Dynamic Radar Cruise Control System - Diagnostic Codes & Circuit Tests (Coupe) >> Dynamic Radar Cruise Control System >> DTC U0100: Lost Communication With ECM/PCM "A"; DTC U0122: Lost Communication With Vehicle Dynamics Control Module; DTC U0125: Lost Communication with Yaw Rate Sensor Module; DTC U0126: Lost Communication with Steering Angle Sensor Module; DTC U0129: Lost Communication with Brake System Control Module; DTC U1104: Lost Communication with Driving Support ECU [03/2017 - 05/2023] >> Description
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DTC U0100: Lost Communication With ECM/PCM "A"; DTC U0122: Lost Communication With Vehicle Dynamics Control Module; DTC U0125: Lost Communication with Yaw Rate Sensor Module; DTC U0126: Lost Communication with Steering Angle Sensor Module; DTC U0129: Lost Communication with Brake System Control Module; DTC U1104: Lost Communication with Driving Support ECU [03/2017 - 05/2023]: Description

When a malfunction is detected between various ECUs and sensors, these DTCs are stored.

DTC No. Detection Item DTC Detection Condition Trouble Area
U0100 Lost Communication With ECM/PCM "A" Condition 1:
  • While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the ECM and the driving support ECU assembly is detected for approximately 1 second or more.

Condition 2:
  • While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the ECM and the skid control ECU assembly is detected for approximately 1 second or more.
Condition 1:
  • CAN communication system
  • ECM
  • Driving support ECU assembly

Condition 2:
  • CAN communication system
  • ECM
  • Skid control ECU assembly
U0122 Lost Communication with Vehicle Dynamics Control Module When the engine switch is turned ON (IG) and the dynamic radar cruise control system is operating, a communication error between the skid control ECU assembly and the ECM is detected for approximately 2.6 seconds or more.
  • CAN communication system
  • ECM
  • Skid control ECU assembly
U0125 Lost Communication with Yaw Rate Sensor Module While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the yaw rate sensor and the driving support ECU assembly is detected for approximately 1 second or more.
  • CAN communication system
  • Yaw rate sensor
  • Driving support ECU assembly
U0126 Lost Communication with Steering Angle Sensor Module While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the steering sensor and the driving support ECU assembly is detected for approximately 1 second or more.
  • CAN communication system
  • Steering sensor
  • Driving support ECU assembly
U0129 Lost Communication with Brake System Control Module While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the skid control ECU assembly and the driving support ECU assembly is detected for approximately 2.5 seconds or more.
  • CAN communication system
  • Skid control ECU assembly
  • Driving support ECU assembly
U1104 Lost Communication with Driving Support ECU Condition 1:
  • While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the driving support ECU assembly and ECM is detected for 1 second or more.

Condition 2:
  • While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the driving support ECU assembly and the millimeter wave radar sensor assembly is detected for approximately 0.2 seconds or more.
Condition 1:
  • CAN communication system
  • ECM
  • Driving support ECU assembly

Condition 2:
  • CAN communication system
  • Millimeter wave radar sensor assembly
  • Driving support ECU assembly