DTC U115C-87: Lost Communication with ECM/PCM "A" (ch5) Missing Message; DTC U1170-87: Lost Communication with Brake System Control Module (ch2) Missing Message; DTC U1171-87: Lost Communication with Brake System Control Module (ch3) Missing Message [03/2023 - ]: Description

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2025 Lexus NX 350, 2025 Lexus NX 250, 2024 Lexus NX 350, 2024 Lexus NX 250, and 2023 Lexus NX 350. However, it is still accessible from the selected car via links, so may be relevant.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	DTC Output from	Priority
U115C-87	Lost Communication with ECM/PCM "A" (ch5) Missing Message	Communication stops between the ECM or engine stop and start ECU and the brake actuator assembly.	CAN main/branch bus lines or connector ECM Engine stop and start ECU Brake actuator assembly No. 2 CAN junction connector	Engine Stop and Start	B
U1170-87	Lost Communication with Brake System Control Module (ch2) Missing Message	Communication stops between the engine stop and start ECU and the brake actuator assembly.	CAN main/branch bus lines or connector Engine stop and start ECU Brake actuator assembly No. 2 CAN junction connector	Stop and Start	B
U1171-87	Lost Communication with Brake System Control Module (ch3) Missing Message	Communication stops between the absorber control ECU and the brake actuator assembly.	CAN main/branch bus lines or connector Absorber control ECU Brake actuator assembly No. 2 CAN junction connector	Adaptive Variable Suspension System	B