U1002

NETWORKING: CAN COMMUNICATION SYSTEM: U1002: Lost Communication with Gateway Module
U1002 - Lost Communication with Gateway Module

DESCRIPTION

* 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.

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

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
* Before measuring the resistance of the CAN bus, turn the power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
* After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notice 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 power switch on (IG), turn the blind spot monitor main switch on, wait at least 10.68 seconds and then drive the vehicle at a speed of 5 km/h (3 mph) or more for at least 10.84 seconds.
* 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 power 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 11

(a) Disconnect the cable from the negative (-) auxiliary 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 11 MAIN LINES (POWER MANAGEMENT CONTROL ECU)

C -- CHECK FOR SHORT IN SUB BUS 11 LINES (POWER MANAGEMENT CONTROL ECU)

D -- CHECK FOR SHORT IN SUB BUS 11 LINES (CAN NO. 2 J/C)
A -- Continue to next step.

2. CHECK FOR DTC OUTPUT

(a) Clear the DTCs.

(b) Turn the power switch off.

(c) Turn the power switch on (IG) and recheck for DTCs.

Result:

B -- GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC

A -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

3. CHECK FOR OPEN IN SUB BUS 11 MAIN LINES (POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the power management control 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 11 MAIN LINES (CAN NO. 2 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

4. CHECK FOR OPEN IN SUB BUS 11 MAIN LINES (CAN NO. 2 J/C - POWER MANAGEMENT CONTROL ECU)

(a) Reconnect the power management control ECU connector.

(b) Disconnect the wire harness connector from the CAN No. 2 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. 2 J/C - POWER MANAGEMENT CONTROL ECU)

C -- CHECK FOR OPEN IN SUB BUS 11 MAIN LINES (CAN NO. 2 J/C - CAN NO. 3 J/C)

A -- REPLACE CAN NO. 2 JUNCTION CONNECTOR

5. CHECK FOR OPEN IN SUB BUS 11 MAIN LINES (CAN NO. 2 J/C - CAN NO. 3 J/C)

(a) Reconnect the wire harness connector to the CAN No. 2 junction 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. 2 J/C - CAN NO. 3 J/C)

C -- CHECK FOR OPEN IN SUB BUS 11 MAIN LINES (CAN NO. 3 J/C - CAN NO. 4 J/C)

A -- REPLACE CAN NO. 3 JUNCTION CONNECTOR

6. CHECK FOR OPEN IN SUB BUS 11 MAIN LINES (CAN NO. 3 J/C - CAN NO. 4 J/C)

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

(b) Disconnect the instrument panel wire 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

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

OK -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

7. CHECK FOR SHORT IN SUB BUS 11 LINES (POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the power management control 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 11 LINES (CAN NO. 2 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

8. CHECK FOR SHORT IN SUB BUS 11 LINES (CAN NO. 2 J/C - POWER MANAGEMENT CONTROL ECU)

(a) Reconnect the power management control ECU connector.

(b) Disconnect the wire harness connector from the CAN No. 2 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. 2 J/C - POWER MANAGEMENT CONTROL ECU)

C -- CHECK FOR SHORT IN SUB BUS 11 LINES (CAN NO. 2 J/C - CAN NO. 3 J/C)

D -- CHECK FOR SHORT IN SUB BUS 11 LINE (ECUS)

A -- REPLACE CAN NO. 2 JUNCTION CONNECTOR

9. CHECK FOR SHORT IN SUB BUS 11 LINES (CAN NO. 2 J/C - CAN NO. 3 J/C)

(a) Reconnect the wire harness connector to the CAN No. 2 junction 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. 2 J/C - CAN NO. 3 J/C)

C -- CHECK FOR SHORT IN SUB BUS 11 LINES (CAN NO. 3 J/C - CAN NO. 4 J/C)

D -- CHECK FOR SHORT IN SUB BUS 11 LINE (ECUS)

A -- REPLACE CAN NO. 3 JUNCTION CONNECTOR

10. CHECK FOR SHORT IN SUB BUS 11 LINES (CAN NO. 3 J/C - 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

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

OK -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

11. CHECK FOR SHORT IN SUB BUS 11 LINE (ECUS)

(a) Reconnect all wire harness connectors (CAN No. 2 junction connector and CAN No. 3 junction connector).

(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 11 LINES (CAN NO. 2 J/C)

(a) Disconnect the wire harness connector from the CAN No. 2 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 11 inspection.
* Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 11 inspection.

B -- CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - POWER MANAGEMENT CONTROL ECU)

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

D -- CHECK CAN BUS LINE (ECUS)

A -- REPLACE CAN NO. 2 JUNCTION CONNECTOR

13. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the power management control 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 11 inspection.
* Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 11 inspection.

NG -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

14. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 2 J/C - 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 11 inspection.
* Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 11 inspection.

B -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - CAN NO. 3 J/C)

C -- CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 3 J/C - CAN NO. 4 J/C)

D -- CHECK CAN BUS LINE (ECUS)

A -- REPLACE CAN NO. 3 JUNCTION CONNECTOR

15. CHECK FOR SHORT IN CAN BUS LINES (CAN NO. 3 J/C - 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

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 11 inspection.
* Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 11 inspection.

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

OK -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

16. CHECK CAN BUS LINE (ECUS)

(a) Reconnect all wire harness connectors (CAN No. 2 junction connector and CAN No. 3 junction connector).

(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 11 inspection.
* If the resistance becomes abnormal when an ECU connector is reconnected, there may be a short in the ECU.

NG -- REPAIR OR REPLACE CORRESPONDING ECU WIRE

OK -- REPLACE CORRESPONDING ECU