Up to 08/2009
NETWORKING: CAN COMMUNICATION SYSTEM: U1002: Lost Communication with Gateway Module (Main Body)
U1002 - Lost Communication with Gateway Module (Main Body)
DESCRIPTION
* The main body 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 CAN MS bus.
* When the main body ECU receives a response signal from the ECUs connected to the CAN MS bus, the main body ECU recognizes and memorizes that the ECU is connected to the CAN MS bus. Based on this memorized data, the main body ECU monitors for malfunctions in the ECUs connected to the CAN MS bus when communicating with those ECUs. If the main body ECU cannot receive response signals from the ECUs that have been memorized as those connected to the CAN MS bus, the main body ECU determines that a malfunction exists.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
* Turn the engine switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
* Turn the engine switch off before inspecting CAN bus wires for a ground short.
* After the engine 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 engine 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 engine 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 CAN MS BUS WIRE
(a) Turn the engine 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 CAN MS BUS WIRES (TILT AND TELESCOPIC ECU)
C -- CHECK FOR SHORT IN CAN MS BUS WIRES (TILT AND TELESCOPIC ECU)
B -- CHECK FOR OPEN IN CAN BUS MAIN WIRE (TILT AND TELESCOPIC ECU)
A -- REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU) Removal
2. CHECK FOR OPEN IN CAN BUS MAIN WIRE (TILT AND TELESCOPIC ECU)
(a) Disconnect the tilt and telescopic ECU connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)
OK -- REPLACE MULTIPLEX TILT AND TELESCOPIC ECU
3. CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)
(a) Reconnect the tilt and telescopic ECU connector.
(b) Disconnect the CAN No. 6 junction connector.
Text in Illustration
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)
OK -- Continue to next step.
4. CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN NO. 6 J/C - MAIN BODY ECU)
(a) Disconnect the CAN No. 6 junction connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR OPEN IN CAN BUS MAIN WIRE (MAIN BODY ECU)
OK -- REPLACE CAN NO. 6 JUNCTION CONNECTOR
5. CHECK FOR OPEN IN CAN BUS MAIN WIRE (MAIN BODY ECU)
(a) Reconnect the CAN No. 6 junction connectors.
(b) Disconnect the main body ECU connector.
Text in Illustration
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - MAIN BODY ECU)
OK -- REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU) Removal
6. CHECK FOR SHORT IN CAN MS BUS WIRES (TILT AND TELESCOPIC ECU)
(a) Disconnect the tilt and telescopic ECU connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)
OK -- REPLACE MULTIPLEX TILT AND TELESCOPIC ECU
7. CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)
(a) Reconnect the tilt and telescopic ECU connector.
(b) Disconnect the CAN No. 6 junction connector.
Text in Illustration
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)
OK -- Continue to next step.
8. CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - MAIN BODY ECU)
(a) Disconnect the CAN No. 6 junction connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- CHECK FOR SHORT IN CAN MS BUS WIRES (MAIN BODY ECU)
OK -- Continue to next step.
9. CHECK FOR CAN MS BUS BRANCH WIRE
(a) Reconnect the CAN No. 6 junction connectors.
(b) Connect the probes of an ohmmeter to terminals CANH and CANL of the tilt and telescopic ECU.
Text in Illustration
(c) While observing the resistance value shown on the tester, disconnect branch wire connector (except F74 and F78) from the CAN No. 6 junction connector until the resistance becomes normal (between 54 and 69 Ohms).
Text in Illustration
HINT
* The connectors connected to the CAN junction connector can be distinguished by the colors of the bus wire.
* Reconnecting the connectors to non-specified positions on the CAN junction connector does not affect system operation.
Result:
B -- CHECK FOR CAN MS BUS BRANCH WIRE
A -- REPLACE CAN NO. 6 JUNCTION CONNECTOR
10. CHECK FOR CAN MS BUS BRANCH WIRE
(a) Reconnect the connector for the short-circuited branch wire to the CAN junction connector (the connector that caused the bus wire 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 wire 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 CAN MS BUS BRANCH WIRE OR CONNECTOR
OK -- REPLACE CORRESPONDING ECU
11. CHECK FOR SHORT IN CAN MS BUS WIRES (MAIN BODY ECU)
(a) Reconnect the CAN No. 6 junction connectors.
(b) Disconnect the main body ECU connector.
Text in Illustration
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - MAIN BODY ECU)
OK -- REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU) Removal
12. CHECK FOR SHORT IN CAN MS BUS WIRES (TILT AND TELESCOPIC ECU)
(a) Disconnect the tilt and telescopic ECU connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.
NG -- CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)
OK -- REPLACE MULTIPLEX TILT AND TELESCOPIC ECU
13. CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)
(a) Disconnect the CAN No. 6 junction connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.
NG -- REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - TILT AND TELESCOPIC ECU)
OK -- Continue to next step.
14. CHECK FOR SHORT IN CAN MS BUS WIRES (CAN NO. 6 J/C - MAIN BODY ECU)
(a) Disconnect the CAN No. 6 junction connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.
NG -- CHECK FOR SHORT IN CAN MS BUS WIRES
OK -- Continue to next step.
15. CHECK FOR CAN MS BUS BRANCH WIRE
(a) Reconnect the CAN No. 6 junction connectors.
(b) Connect the probes of an ohmmeter to terminals CANH or CANL and GND or +B of the tilt and telescopic ECU.
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 CAN MS Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.
(c) While observing the resistance value shown on the tester, disconnect branch wire connector (except F74 and F78) from the CAN No. 6 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
HINT
* The connectors connected to the CAN junction connector can be distinguished by the colors of the bus wire.
* Reconnecting the connectors to non-specified positions on the CAN junction connector does not affect system operation.
Result:
B -- CHECK FOR CAN MS BUS BRANCH WIRE
A -- REPLACE CAN NO. 6 JUNCTION CONNECTOR
16. CHECK FOR CAN MS BUS BRANCH WIRE
(a) Reconnect the connector for the bus wire that is shorted to +B or GND to the CAN junction connector (the connector that caused the bus wire 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 wire shorted to +B or GND 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 when the connector is disconnected from the ECU, there may be a short in the ECU.
NG -- REPAIR OR REPLACE CAN MS BUS BRANCH WIRE OR CONNECTOR
OK -- REPLACE CORRESPONDING ECU
17. CHECK FOR SHORT IN CAN MS BUS WIRES
(a) Disconnect the main body ECU connector.
Text in Illustration
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check CAN MS Bus Wire inspection.
Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check CAN MS Bus Wire inspection.
NG -- REPAIR OR REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR (CAN NO. 6 J/C - MAIN BODY ECU)
OK -- REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU) Removal