Lost Communication with Gateway Module (MS Bus)

NETWORKING: CAN COMMUNICATION SYSTEM: U1002, U1114: Lost Communication with Gateway Module (MS Bus)
U1114 - Lost Communication with Main Switch Module

DESCRIPTION

* The main body ECU (multiplex network body ECU) stores this DTC when no signals can be received from the ECUs that are memorized as those connected to the CAN MS bus.

* When the main body ECU (multiplex network body ECU) receives a response signal from the ECUs connected to the CAN MS bus, the main body ECU (multiplex network body ECU) recognizes and memorizes that the ECU is connected to the CAN MS bus. Based on this memorized data, the main body ECU (multiplex network body ECU) monitors for malfunctions in the ECUs connected to the CAN MS bus when communicating with those ECUs. If the main body ECU (multiplex network body ECU) cannot receive response signals from the ECUs that are memorized as those connected to the CAN MS bus, the main body ECU (multiplex network body ECU) determines that a malfunction exists.

* If 2 or more DTCs are output during the DTC check, one side of the CAN branch wire may be open (one side of the CANH [branch wire]/CANL [branch wire] of the ECU and/or sensor is open).

HINT
For vehicles with CRAWL control only.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT
Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

PROCEDURE

1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

(a) Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and branch wire.

CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.

NEXT -- Continue to next step.

2. CHECK FOR OPEN IN CAN BUS MAIN WIRE (MAIN BODY ECU - DRIVE MONITOR SWITCH)

(a) Disconnect the F10 main body ECU (multiplex network body ECU) connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Text in Illustration

NG -- CONNECT CONNECTOR
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY AND BODY GROUND)

(a) Connect the cable to the negative (-) battery terminal.

Text in Illustration

NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.

(b) Remove the main body ECU (multiplex network body ECU) Removal.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Removal

4. CONNECT CONNECTOR

(a) Reconnect the F10 main body ECU (multiplex network body ECU) connector.

NEXT -- Continue to next step.

5. CHECK FOR OPEN IN CAN BUS MAIN WIRE (DRIVE MONITOR SWITCH - MAIN BODY ECU)

(a) Disconnect the U1 drive monitor switch connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Text in Illustration

NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (MAIN BODY ECU - DRIVE MONITOR SWITCH)
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (DRIVE MONITOR SWITCH - BATTERY AND BODY GROUND)

(a) Connect the cable to the negative (-) battery terminal.

NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Text in Illustration

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE DRIVE MONITOR SWITCH Removal