Part 1
NETWORKING: CAN COMMUNICATION SYSTEM: U1002 (CAN MS BUS): Lost Communication with Gateway Module (Main body ECU)
U1002 (CAN MS BUS) - Lost Communication with Gateway Module (Main body ECU)
DESCRIPTION
If 2 or more DTCs are output during the DTC check, one side of the CAN branch wire may be open (One side of the CANH [branch wire]/CANL [branch wire] of the ECU and/or sensor is open).
* *1: w/ Memory
* *2: w/ Power Back Door
* *3: for Power Seat with Memory
* *4: w/ Power Slide Door
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
* Turn the ignition switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
* Turn the ignition switch off before inspecting CAN bus wires for a ground short.
* After the ignition 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 ignition 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 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. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL
(a) Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and the branch wire.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
NOTICE:
When disconnecting the cable, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.
NEXT -- Continue to next step.
2. CHECK CAN BUS WIRE (MAIN WIRE FOR DISCONNECTION, BUS LINE FOR SHORT CIRCUIT)
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
Result
C -- CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - BATTERY AND BODY GROUND)
B -- CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN JUNCTION CONNECTOR - COMBINATION METER)
A -- Continue to next step.
3. CHECK FOR OPEN IN MAIN BUS WIRE (NO. 2 CAN JUNCTION CONNECTOR - MAIN BODY ECU)
(a) Disconnect the D120 No. 2 CAN junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
4. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 2 CAN JUNCTION CONNECTOR - COMBINATION METER)
(a) Disconnect the D117 No. 2 CAN junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- REPAIR OR REPLACE NO. 2 CAN JUNCTION CONNECTOR
5. CONNECT CONNECTOR
(a) Reconnect the D120 No. 2 CAN junction connector connector.
NEXT -- Continue to next step.
6. CHECK FOR OPEN IN CAN BUS MAIN WIRE (MAIN BODY ECU - NO. 2 CAN JUNCTION CONNECTOR)
(a) Disconnect the D14 main body ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO MAIN BODY ECU (MAIN BODY ECU - NO. 2 CAN JUNCTION CONNECTOR)
OK -- REPLACE MAIN BODY ECU Removal
7. CONNECT CONNECTOR
(a) Reconnect the D117 and D120 No. 2 CAN junction connector connectors.
NEXT -- Continue to next step.
8. CHECK FOR OPEN IN CAN BUS MAIN WIRE (COMBINATION METER - NO. 2 CAN JUNCTION CONNECTOR)
(a) Disconnect the D18 combination meter connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO COMBINATION METER (COMBINATION METER - NO. 2 CAN JUNCTION CONNECTOR)
OK -- REPLACE COMBINATION METER Removal
9. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN JUNCTION CONNECTOR - COMBINATION METER)
(a) Disconnect the D117 No. 2 CAN junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
10. CONNECT CONNECTOR
(a) Reconnect the D117 No. 2 CAN junction connector connector.
NEXT -- Continue to next step.
11. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN JUNCTION CONNECTOR - OUTER MIRROR CONTROL ECU ASSEMBLY RH)
(a) Disconnect the D118 No. 2 CAN junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
12. CONNECT CONNECTOR
(a) Reconnect the D118 No. 2 CAN junction connector connector.
NEXT -- Continue to next step.
13. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN JUNCTION CONNECTOR - SLIDE DOOR MOTOR UNIT RH)
(a) Disconnect the D119 No. 2 CAN junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
14. CONNECT CONNECTOR
(a) Reconnect the D119 No. 2 CAN junction connector connector.
NEXT -- Continue to next step.
15. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN JUNCTION CONNECTOR - POSITION CONTROL ECU AND SWITCH)
(a) Disconnect the D121 No. 2 CAN junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- CONNECT CONNECTOR
OK -- Continue to next step.