DTC U1002: Lost Communication with Gateway Module [08/2013 - ]: Description

WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.

The power management control ECU will store this DTC when no signals can be received from the ECUs that have been memorized as those that are connected to sub bus 11.
When the power management control ECU receives a response signal from the ECUs connected to sub bus 11, the power management control ECU recognizes and memorizes that the ECU is connected to sub bus 11. Based on this memorized data, the power management control ECU monitors for malfunctions in the ECUs connected to sub bus 11 when communicating with those ECUs. If the power management control ECU cannot receive response signals from the ECUs that have been memorized as those connected to sub bus 11, the power management control ECU determines that a malfunction exists.

DTC No.	DTC Detection Condition	Trouble Area
U1002	The power management control ECU cannot receive signals from all ECUs that have been memorized as those connected to sub bus 11.	Open or short in sub bus 11 main line or connector Open or short in sub bus 11 branch line or connector Power management control ECU Seat belt control ECU1 Driving support ECU assembly1 Lane departure warning camera23 Blind spot monitor sensor LH4 Open or short in CAN junction connector RH3 Open or short in CAN No. 3 junction connector2 Open or short in CAN No. 4 junction connector Open or short in CAN No. 5 junction connector

*1: w/ Dynamic radar cruise control system
*2: w/o Dynamic radar cruise control system
*3: w/ Lane departure alert system
*4: w/ Blind spot monitor system

HINT:

This diagnosis procedure is for when DTC U1002 is output by the power management control ECU (Techstream display: PM1 Gateway).