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Home >> Lexus >> 2021 >> NX 300 Base, AWD >> Repair and Diagnosis (Single Page) >> Brakes >> Parking Brake System >> Electric Parking Brake System - Diagnostics Codes >> Electric Parking Brake System >> DTC U0073: Control Module Communication Bus OFF; DTC U0100: Lost Communication with ECM / PCM; DTC U0124: Lost Communication with Lateral Acceleration Sensor Module; DTC U0129: Lost Communication with Brake System Control Module [05/2019 - ] >> Description
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DTC U0073: Control Module Communication Bus OFF; DTC U0100: Lost Communication with ECM / PCM; DTC U0124: Lost Communication with Lateral Acceleration Sensor Module; DTC U0129: Lost Communication with Brake System Control Module [05/2019 - ]: Description

The parking brake ECU assembly communicates with the ECM, skid control ECU (brake actuator assembly) and deceleration sensor (airbag ECU assembly) via CAN communication.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory Note
U0073 Control Module Communication Bus OFF With the engine switch on (IG), the bus is off (communication with other ECUs is not possible) CAN communication system Yes An electric parking brake system malfunction is displayed on the multi-information display.
U0100 Lost Communication with ECM / PCM With the engine switch on (IG) and the vehicle being driven at 15 km/h (9 mph) or more, the parking brake ECU assembly cannot receive signals from the ECM for approximately 1 second or 10 seconds (malfunction duration differs depending on the signal).
  • CAN communication system
  • ECM
Yes An electric parking brake system malfunction is displayed on the multi-information display.
U0124 Lost Communication with Lateral Acceleration Sensor Module With the engine switch on (IG) and the vehicle being driven at 7 km/h (4.3 mph) or more, the parking brake ECU assembly cannot receive signals from the deceleration sensor (airbag ECU assembly).
  • CAN communication system
  • Deceleration sensor (Airbag ECU assembly)
Yes An electric parking brake system malfunction is displayed on the multi-information display.
U0129 Lost Communication with Brake System Control Module With the engine switch on (IG), the parking brake ECU assembly cannot receive signals from the skid control ECU (brake actuator assembly) for approximately 1 second or 10 seconds (malfunction duration differs depending on the signal).
  • CAN communication system
  • Skid control ECU (Brake actuator assembly)
Yes An electric parking brake system malfunction is displayed on the multi-information display.