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Home >> Lexus >> 2019 >> RC 350 Base, AWD >> Repair and Diagnosis (Single Page) >> Brakes >> Traction Control >> Vehicle Stability Control System - Diagnostic Codes (2 Of 5) >> Vehicle Stability Control System >> DTC C1203: ECM Communication Circuit Malfunction; DTC C1270: Initialization Incomplete (Test Mode DTC) [10/2015 - 11/2017] >> Description
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DTC C1203: ECM Communication Circuit Malfunction; DTC C1270: Initialization Incomplete (Test Mode DTC) [10/2015 - 11/2017]: Description

This circuit is used to send TRAC and VSC operation information from the skid control ECU (brake actuator assembly) to the ECM, and engine control information from the ECM to the skid control ECU (brake actuator assembly) via CAN communication.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1203 ECM Communication Circuit Malfunction Any of the following is detected:
  1. Engine, drivetrain and destination information sent from the ECM does not match the information stored in the skid control ECU (brake actuator assembly).
  2. The information on whether the front steering control ECU is installed does not match the information stored in the skid control ECU (brake actuator assembly). (w/ VGRS System)
  3. The information on whether the rear steering control ECU is installed does not match the information stored in the skid control ECU (brake actuator assembly). (w/ DRS System)
  4. No stored information for destination.
  • An incorrect ECU is installed.
  • Skid control ECU (brake actuator assembly)
C1270 Initialization Incomplete (Test Mode DTC) Detected only during Test Mode.
  • ECM
  • Skid control ECU (brake actuator assembly)
  • CAN communication system (skid control ECU to ECM)
  • CAN communication system (skid control ECU to front steering control ECU)
  • CAN communication system (skid control ECU to rear steering control ECU)