U1002

NETWORKING: CAN COMMUNICATION SYSTEM: U1002: Lost Communication with Gateway Module (Network Gateway ECU)
U1002 - Lost Communication with Gateway Module (Network Gateway ECU)

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.

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

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
* Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
* After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Service Precautions.
* Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output How to Proceed With Troubleshooting.
* After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
* DTC check procedure: Turn the ignition switch to ON, turn the blind spot monitor system on using the blind spot monitor main switch (ON/OFF switch), wait at least 22 seconds, and then drive the vehicle at a speed of 5 km/h (3 mph) or more.
* After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed Diagnosis System.

HINT
* Operating the ignition switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
* Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

1. CHECK SUB BUS 2

(a) Disconnect the cable from the negative (-) battery terminal.

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

Standard Resistance:

Text in Illustration

Result:

B -- CHECK FOR OPEN IN SUB BUS 2 LINES (NETWORK GATEWAY ECU)

C -- CHECK FOR SHORT IN SUB BUS 2 LINES (NETWORK GATEWAY ECU)

D -- CHECK FOR SHORT IN SUB BUS 2 LINE (CAN NO. 3 J/C)
A -- Continue to next step.

2. CHECK FOR DTC OUTPUT

(a) Clear the DTCs.

(b) Turn the ignition switch off.

(c) Turn the ignition switch to ON and recheck for DTCs.

Result:

B -- GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC

A -- REPLACE NETWORK GATEWAY ECU Removal

3. CHECK FOR OPEN IN SUB BUS 2 LINES (NETWORK GATEWAY ECU)

(a) Disconnect the network gateway ECU connector.

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

Standard Resistance:

Text in Illustration

NG -- CHECK FOR OPEN IN SUB BUS 2 LINES (CAN NO. 3 J/C)

OK -- REPLACE NETWORK GATEWAY ECU Removal

4. CHECK FOR OPEN IN SUB BUS 2 LINES (CAN NO. 3 J/C)

(a) Reconnect the network gateway ECU connector.

(b) Disconnect the wire harness connector from the CAN No. 3 junction connector.

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

Standard Resistance:

Text in Illustration

Result:

B -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - NETWORK GATEWAY ECU)

C -- CHECK FOR OPEN IN SUB BUS 2 LINES (CAN NO. 4 J/C)

A -- REPLACE CAN NO. 3 JUNCTION CONNECTOR

5. CHECK FOR OPEN IN SUB BUS 2 LINES (CAN NO. 4 J/C)

(a) Reconnect the wire harness connector to the CAN No. 3 junction connector.

(b) Disconnect the wire harness connector from the CAN No. 4 junction connector.

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

Standard Resistance:

Text in Illustration

Result:

B -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - CAN NO. 4 J/C)

C -- CHECK FOR OPEN IN SUB BUS 2 LINES (CAN NO. 5 J/C)

A -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

6. CHECK FOR OPEN IN SUB BUS 2 LINES (CAN NO. 5 J/C)

(a) Reconnect the wire harness connector to the CAN No. 4 junction connector.

(b) Disconnect the instrument panel wire from the CAN No. 5 junction connector.

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

Standard Resistance:

Text in Illustration

NG -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 4 J/C - CAN NO. 5 J/C)

OK -- REPLACE CAN NO. 5 JUNCTION CONNECTOR

7. CHECK FOR SHORT IN SUB BUS 2 LINES (NETWORK GATEWAY ECU)

(a) Disconnect the network gateway ECU connector.

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

Standard Resistance:

Text in Illustration

NG -- CHECK FOR SHORT IN SUB BUS 2 LINES (CAN NO. 3 J/C)

OK -- REPLACE NETWORK GATEWAY ECU Removal

8. CHECK FOR SHORT IN SUB BUS 2 LINES (CAN NO. 3 J/C)

(a) Reconnect the network gateway ECU connector.

(b) Disconnect the wire harness connector from the CAN No. 3 junction connector.

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

Standard Resistance:

Text in Illustration

Result:

B -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - NETWORK GATEWAY ECU)

C -- CHECK FOR SHORT IN SUB BUS 2 LINES (CAN NO. 4 J/C)

D -- CHECK FOR SHORT IN SUB BUS 2 LINES (ECUS)

A -- REPLACE CAN NO. 3 JUNCTION CONNECTOR

9. CHECK FOR SHORT IN SUB BUS 2 LINES (CAN NO. 4 J/C)

(a) Reconnect the wire harness connector to the CAN No. 3 junction connector.

(b) Disconnect the wire harness connector from the CAN No. 4 junction connector.

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

Standard Resistance:

Text in Illustration

Result:

B -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - CAN NO. 4 J/C)

C -- CHECK FOR SHORT IN SUB BUS 2 LINES (CAN NO. 5 J/C)

D -- CHECK FOR SHORT IN SUB BUS 2 LINES (ECUS)

A -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

10. CHECK FOR SHORT IN SUB BUS 2 LINES (CAN NO. 5 J/C)

(a) Reconnect the wire harness connector to the CAN No. 4 junction connector.

(b) Disconnect the wire harness connector from the CAN No. 5 junction connector.

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

Standard Resistance:

Text in Illustration

NG -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 4 J/C - CAN NO. 5 J/C)

OK -- REPLACE CAN NO. 5 JUNCTION CONNECTOR

11. CHECK FOR SHORT IN SUB BUS 2 LINES (ECUS)

(a) Reconnect all wire harness connectors (CAN J/C3 and CAN J/C4).

(b) Disconnect the connector that includes terminals CANH and CANL from the ECU (or sensor) to which the short-circuited branch line is connected CAN Communication System.

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

Standard Resistance:

Text in Illustration

HINT
* If the resistance becomes normal (between 54 and 69 Ohms) when the connector is disconnected from the ECU (or sensor), there may be a short in the ECU (or sensor).
* If the resistance does not become normal (between 54 and 69 Ohms) when the connector is disconnected from the ECU (or sensor), repair or replace the short-circuited branch line or connector.

NG -- REPAIR OR REPLACE CORRESPONDING ECU WIRE

OK -- REPLACE CORRESPONDING ECU

12. CHECK FOR SHORT IN SUB BUS 2 LINE (CAN NO. 3 J/C)

(a) Disconnect the wire harness connector from the CAN No. 3 junction connector.

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

Standard Resistance:

Text in Illustration

Result:

HINT
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 2 inspection.

Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 2 inspection.

B -- CHECK FOR SHORT IN SUB BUS 2 LINE (NETWORK GATEWAY ECU)

C -- CHECK FOR SHORT IN SUB BUS 2 LINE (CAN NO. 4 J/C)

D -- CHECK SUB BUS 2 LINE (ECUS)

A -- REPLACE CAN NO. 3 JUNCTION CONNECTOR

13. CHECK FOR SHORT IN SUB BUS 2 LINE (NETWORK GATEWAY ECU)

(a) Disconnect the network gateway ECU connector.

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

Standard Resistance:

Text in Illustration

HINT
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 2 inspection.

Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 2 inspection.

NG -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - NETWORK GATEWAY ECU)

OK -- REPLACE NETWORK GATEWAY ECU Removal

14. CHECK FOR SHORT IN SUB BUS 2 LINE (CAN NO. 4 J/C)

(a) Disconnect the wire harness connector from the CAN No. 4 junction connector.

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

Standard Resistance:

Text in Illustration

Result:

HINT
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 2 inspection.

Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 2 inspection.

B -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 3 J/C - CAN NO. 4 J/C)

C -- CHECK FOR SHORT IN SUB BUS 2 LINE (CAN NO. 5 J/C)

D -- CHECK SUB BUS 2 LINE (ECUS)

A -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

15. CHECK FOR SHORT IN SUB BUS 2 LINE (CAN NO. 5 J/C)

(a) Disconnect the wire harness connector from the CAN No. 5 junction connector.

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

Standard Resistance:

Text in Illustration

HINT
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 2 inspection.

Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 2 inspection.

NG -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 4 J/C - CAN NO. 5 J/C)

OK -- REPLACE CAN NO. 5 JUNCTION CONNECTOR

16. CHECK SUB BUS 2 LINE (ECUS)

(a) Reconnect all wire harness connectors (CAN J/C3 and CAN J/C4).

(b) Disconnect the connector that includes terminals CANH and CANL from the ECU to which the bus line shorted to B+ or shorted to GND is connected.

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

Standard Resistance:

Text in Illustration

HINT
* It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 2 inspection.
* If the resistance becomes abnormal when an ECU connector is reconnected, there may be a short in the ECU.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 2 inspection.

NG -- REPAIR OR REPLACE CORRESPONDING ECU WIRE

OK -- REPLACE CORRESPONDING ECU