DTC U0100-87: Lost Communication with ECM/PCM "A" Missing Message; DTC U0126-87: Lost Communication with Steering Angle Sensor Module Missing Message; DTC U0129-87: Lost Communication with Brake System Control Module Missing Message [10/2022 - ]: Description

WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

The 4WD ECU assembly receives signals from the ECM, steering sensor and skid control ECU (brake actuator assembly) via CAN communication.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory	DTC Output from	Priority
U0100-87	Lost Communication with ECM/PCM "A" Missing Message	When the ignition switch is ON, the IG1 terminal voltage is 10 V or more and the vehicle speed is 60 km/h (37 mph) or more, signals cannot be received from the ECM for 1 second or more	CAN communication system 4WD ECU assembly ECM	Displayed	Yes	Four Wheel Drive	B
U0126-87	Lost Communication with Steering Angle Sensor Module Missing Message	When the following continues: When the IG1 terminal voltage is 10 V or more, communication with the steering sensor is impossible for 1 second or more When the IG1 terminal voltage is 10 V or more, a condition in which communication with the steering sensor is impossible occurs 1 time or more within a 5-second period, and this occurs 10 times within 60 seconds	CAN communication system 4WD ECU assembly Steering sensor	Displayed	Yes	Four Wheel Drive	B
U0129-87	Lost Communication with Brake System Control Module Missing Message	When the IG1 terminal voltage is 10 V or more, communication with the skid control ECU (brake actuator assembly) is impossible for 3 seconds or more	CAN communication system 4WD ECU assembly Skid control ECU (Brake actuator assembly)	Displayed	Yes	Four Wheel Drive	B