DTC P3123-87: Lost Communication with Drive Motor Control Module "A" from Hybrid/EV Control Module Missing Message [10/2018 - ]: Description

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.

For a description of the inverter.

Refer to DTC P0D2D-16: Drive Motor "A" Inverter Voltage Sensor(VH) Circuit Voltage Below Threshold; DTC P0D2D17: Drive Motor "A" Inverter Voltage Sensor(VH) Circuit Voltage Above Threshold; DTC P0D2D1F: Drive Motor "A" Inverter Voltage Sensor(VH) Circuit Intermittent [10/2018 - ]

The MG ECU, which is built into in the inverter with converter assembly, controls motor (MG2) based on commands from the hybrid vehicle control ECU. The MG ECU monitors communication data and detects malfunctions.

The hybrid vehicle control ECU monitors communication data and detects malfunctions.

A communication error between the MG ECU and the hybrid vehicle control ECU.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate
P312387	Lost Communication with Drive Motor Control Module "A" from Hybrid/EV Control Module Missing Message	Error in reception from inverter with converter assembly (MG ECU) via serial communication (out of communication standard) (1 trip detection logic)	Wire harness or connector Inverter with converter assembly Hybrid vehicle transaxle assembly Hybrid vehicle control ECU PCU FR fuse	Comes on	Master Warning: Comes on