Power Management1

NETWORKING: CAN COMMUNICATION SYSTEM: U1002: Lost Communication with Gateway Module (Power Management1)
U1002 - Lost Communication with Gateway Module (Power Management1)

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 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 power switch on (IG), wait at least 20 seconds, and then drive the vehicle at a speed of 50 km/h (31 mph) or more at least 1.72 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.
* Connectors that connect to the CAN junction connector can be distinguished by color of their CAN bus lines. When the connectors have been disconnected from the CAN junction connector, reconnecting the connectors to non-original positions on the CAN junction connector does not affect system performance. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.

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

HINT
When the value is as specified, clear and recheck for DTCs. When no DTCs are output, check for malfunctions such as damage or improper connection of the relevant connectors.

Result:

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

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

D -- CHECK FOR SHORT IN SUB BUS 11 BUS LINE (POWER MANAGEMENT CONTROL ECU)

A -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

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

(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. 4 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

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

(a) Reconnect the power management control ECU connector.

(b) Disconnect the power management control ECU main line connector from the CAN No. 4 junction connector.

Text in Illustration

NOTICE:
* Before disconnecting the connector, make a note of where it is connected.
* Reconnect the connector to its original position.

NG -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

4. 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. 4 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

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

(a) Reconnect the power management control ECU connector.

(b) Disconnect the power management control ECU main line connector from the CAN No. 4 junction connector.

Text in Illustration

NOTICE:
* Before disconnecting the connector, make a note of where it is connected.
* Reconnect the connector to its original position.

NG -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)
OK -- Continue to next step.

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

(a) Reconnect the power management control ECU main line connector to the CAN No. 4 junction connector.

(b) Connect the probes of an ohmmeter to terminals 34 (CA2H) and 35 (CA2L) of the power management control ECU.

Text in Illustration

(c) While observing the resistance value shown on the ohmmeter, disconnect branch line connectors (except L100) from the CAN No. 4 junction connector until the resistance becomes normal (between 54 and 69 Ohms).

Text in Illustration

Junction Connector A Side

Junction Connector B Side

HINT
* Connectors that connect to the CAN junction connector can be distinguished by the color of their CAN bus lines.
* Reconnecting the connectors to non-original positions on the CAN junction connector does not affect system performance. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.

Result:

B -- CHECK FOR SHORT IN SUB BUS 11 LINES (ECUS)

A -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

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

(a) Reconnect the connector for the short-circuited branch line to the CAN junction connector (the connector that caused the bus line resistance to become normal (between 54 and 69 Ohms) when it was disconnected).

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

(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, there may be a short in the ECU.

NG -- REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR BRANCH LINE OR CONNECTOR

OK -- REPLACE CORRESPONDING ECU OR SENSOR

8. CHECK FOR SHORT IN SUB BUS 11 BUS LINE (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 -- CHECK FOR SHORT IN SUB BUS 11 LINE (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

9. CHECK FOR SHORT IN SUB BUS 11 LINE (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the power management control ECU main line connector from the CAN No. 4 junction connector.

Text in Illustration

NOTICE:
* Before disconnecting the connector, make a note of where it is connected.
* Reconnect the connector to its original position.

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

Standard Resistance:

NG -- REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)
OK -- Continue to next step.

10. CHECK FOR SHORT IN SUB BUS 11 LINE (CAN NO. 4 J/C)

(a) Reconnect the power management control ECU main line connector to the CAN No. 4 junction connector.

(b) Connect the probes of an ohmmeter to terminals CANH or CANL and GND or +B (AM22) of the power management control ECU.

Text in Illustration

HINT
* It is only necessary to perform the inspection for the result (short circuit) that was obtained in the Check Sub Bus 11 Line inspection.
* The connectors connected to the CAN junction connector can be distinguished according to the color of the communication bus lines and the shape of the connectors.
* Reconnecting the connectors to non-specified positions on the CAN junction connector does not affect system operation. However, it is preferred to reconnect the connectors to their specified positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.

(c) While observing the resistance value shown on the ohmmeter, disconnect branch line connectors (except L100) from the CAN No. 4 junction connector until the resistance becomes normal (6 kOhms or higher (for +B short) or 200 Ohms or higher (for ground short)).

Text in Illustration

Junction Connector A Side

Junction Connector B Side

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

A -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

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

(a) Reconnect the connector for the bus line that is shorted to +B or GND to the CAN junction connector (the connector that caused the bus line resistance to change to 6 kOhms or higher (for +B short) or 200 Ohms or higher (for ground short) when it was disconnected).

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

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

Standard Resistance:

NG -- REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR BRANCH LINE OR CONNECTOR

OK -- REPLACE CORRESPONDING ECU OR SENSOR