Part 1
CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: U1002: Lost Communication with Gateway Module
U1002 - Lost Communication with Gateway Module
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.)
HINT
*1: w/ Front Power Seat Control System (w/ Memory)
*2: w/ Rear Power Seat Control System (except 4-Passanger with Ottoman) or w/ Seat Heater System
*3: w/ Rear Power Seat Control System (for 4-Passanger with Ottoman)
*4: w/ Dynamic Radar Cruise Control System, w/ Pre-collision System or w/ Lane Keeping Assist System
*5: w/ Power Trunk Lid System
WIRING DIAGRAM
INSPECTION PROCEDURE
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 prevent airbag and seat belt pretensioner activation.
NOTICE:
* w/ Navigation System (for HDD):
After the engine switch is turned off, the display and navigation module display (HDD navigation system) records various types of memory and settings. As a result, after turning the engine switch off, be sure to wait for the time specified in the following table before disconnecting the cable from the negative (-) battery terminal.
Waiting Time before Disconnecting Cable from Negative (-) Battery Terminal:
* 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:
Result
C -- CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY AND BODY GROUND)
B -- CHECK FOR SHORT IN CAN BUS WIRES (NO. 12 JUNCTION CONNECTOR SIDE)
A -- Continue to next step.
3. CHECK FOR OPEN IN CAN MAIN BUS WIRE (NO. 10 JUNCTION CONNECTOR - FRONT CONTROLLER)
(a) Disconnect the L95 No. 10 junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
4. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 10 JUNCTION CONNECTOR - REAR JUNCTION BLOCK ECU)
(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- CONNECT CONNECTOR
OK -- REPLACE NO. 10 JUNCTION CONNECTOR
5. CONNECT CONNECTOR
(a) Reconnect the L95 No. 10 junction connector connector.
NEXT -- Continue to next step.
6. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 9 JUNCTION CONNECTOR - FRONT CONTROLLER)
(a) Disconnect the R48 No. 9 junction connector connector.
Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
7. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 9 JUNCTION CONNECTOR - NO. 10 JUNCTION CONNECTOR)
(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 9 JUNCTION CONNECTOR - NO. 10 JUNCTION CONNECTOR)
OK -- REPLACE NO. 9 JUNCTION CONNECTOR
8. CONNECT CONNECTOR
(a) Reconnect the R48 No. 9 junction connector connector.
NEXT -- Continue to next step.
9. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 8 JUNCTION CONNECTOR - FRONT CONTROLLER)
(a) Disconnect the R57 No. 8 junction connector connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- CONNECT CONNECTOR
OK -- Continue to next step.
10. CHECK FOR OPEN IN CAN BUS MAIN WIRE (NO. 8 JUNCTION CONNECTOR - NO. 9 JUNCTION CONNECTOR)
(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (NO. 8 JUNCTION CONNECTOR - NO. 9 JUNCTION CONNECTOR)
OK -- REPLACE NO. 8 JUNCTION CONNECTOR