DTC U1002: Lost Communication with Gateway Module (Network Gateway ECU) [08/2016 - 11/2017]: Description

The network gateway 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 2.
When the network gateway ECU receives a response signal from the ECUs connected to sub bus 2, the network gateway ECU recognizes and memorizes that the ECU is connected to sub bus 2. Based on this memorized data, the network gateway ECU monitors for malfunctions in the ECUs connected to sub bus 2 when communicating with those ECUs. If the network gateway ECU cannot receive response signals from the ECUs that have been memorized as those connected to sub bus 2, the network gateway ECU determines that a malfunction exists.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
U1002	Lost Communication with Gateway Module (Network Gateway ECU)	The network gateway ECU cannot receive signals from all ECUs that have been memorized as those connected to sub bus 2.	Open or short in sub bus 2 main lines or connector Short in sub bus 2 branch lines or connector Network gateway ECU Driving support ECU assembly (w/ Pre-collision System) Clearance warning ECU assembly (w/ Intuitive Parking Assist System) Option connector (bus buffer ECU) Lane departure warning camera (w/ Lane Departure Alert System) Blind spot monitor sensor LH (w/ Blind Spot Monitor System) Telematics transceiver (for Lexus Enform Remote Compatible Type) Headlight leveling ECU assembly (for Single Beam Headlight) Absorber control ECU Open or short in No. 3 CAN junction connector Open or short in No. 4 CAN junction connector Open or short in No. 7 CAN junction connector Open or short in No. 9 CAN junction connector Open or short in No. 2 CAN junction terminal	HINT: The network gateway ECU stores DTCs when it detects a communication stop or network communication error for ECUs connected to sub bus 2.

HINT:

This diagnostic procedure is for when DTC U1002 is output by the network gateway ECU (Techstream display: Gateway).