Lost Communication With Gateway Module (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 the V2 bus.

* When the power management control ECU receives a response signal from the ECUs connected to the V2 bus, the power management control ECU recognizes and memorizes that the ECU is connected to the V2 bus. Based on this memorized data, the power management control ECU monitors for malfunctions in the ECUs connected to the V2 bus 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 the V2 bus, 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:
* After turning the power 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 notice before proceeding with work Service Precautions.
* Turn the power switch off before measuring the resistances between CAN main bus lines and between CAN branch lines.
* Turn the power switch off before inspecting CAN bus lines for a ground short.
* After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
* Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

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 V2 BUS LINES

(a) Turn the power switch off.

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

Standard Resistance:

Text in Illustration

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

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

Standard Resistance:

Result:

D -- CHECK FOR SHORT IN V2 BUS LINE (POWER MANAGEMENT CONTROL ECU)

C -- CHECK FOR SHORT IN V2 BUS LINES (POWER MANAGEMENT CONTROL ECU)

B -- CHECK FOR OPEN IN V2 BUS MAIN LINES (POWER MANAGEMENT CONTROL ECU MAIN WIRE)
A -- Continue to next step.

2. CHECK 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 V2 BUS MAIN LINES (POWER MANAGEMENT CONTROL ECU MAIN WIRE)

(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 V2 BUS MAIN LINES (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

4. CHECK FOR OPEN IN V2 BUS 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

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

5. CHECK FOR SHORT IN V2 BUS 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 V2 BUS LINES (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

6. CHECK FOR SHORT IN V2 BUS 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

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

7. CHECK FOR SHORT IN V2 BUS 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 H106) from the CAN No. 4 junction connector until the resistance becomes normal (between 54 and 69 Ohms).

Text in Illustration

Junction Connector B Side

Junction Connector A Side

HINT
* The connectors connected to the CAN junction connector can be distinguished by the colors of the bus line.
* Reconnecting the connectors to non-specified positions on the CAN junction connector does not affect system operation.

Result:

B -- CHECK FOR SHORT IN V2 BUS LINES (ECUS)

A -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

8. CHECK FOR SHORT IN V2 BUS 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

9. CHECK FOR SHORT IN V2 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 V2 Bus Line inspection.

Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check V2 Bus Line inspection.

NG -- CHECK FOR SHORT IN V2 BUS LINE (CAN NO. 4 J/C - POWER MANAGEMENT CONTROL ECU)

OK -- REPLACE POWER MANAGEMENT CONTROL ECU Removal

10. CHECK FOR SHORT IN V2 BUS 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

(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.

11. CHECK FOR SHORT IN V2 BUS 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 V2 Bus Line inspection.

(c) While observing the resistance value shown on the ohmmeter, disconnect branch line connectors (except H106) 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 B Side

Junction Connector A Side

B -- CHECK FOR SHORT IN V2 BUS LINE (ECUS)

A -- REPLACE CAN NO. 4 JUNCTION CONNECTOR

12. CHECK FOR SHORT IN V2 BUS 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