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Home >> Lexus >> 2012 >> LS 460 AWD V8-4.6L (1UR-FSE) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Information Bus >> Testing and Inspection >> Component Tests and General Diagnostics >> Open in One Side of CAN Branch Line

Open in One Side of CAN Branch Line





CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: Open in One Side of CAN Branch Line
- Open in One Side of CAN Branch Line

DESCRIPTION

If 2 or more ECUs and/or sensors do not appear on the Techstream's "CAN Bus Check" screen, 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/ Multi-display

*2: w/o Multi-display

WIRING DIAGRAM









INSPECTION PROCEDURE

HINT
* Perform the following inspection for the ECUs (sensors) which are not displayed on the Techstream. If a malfunction cannot be identified, perform the following inspections for the ECUs (sensors) connected to the CAN communication system.
* Do not remove the center airbag sensor and ECM, as they are the end parts of the circuit. If removed, CAN communication will not be possible.
* The open circuit confirmation of the center airbag sensor, ECM and main wire is performed in the CHECK CAN BUS LINE procedure of HOW TO PROCEED WITH TROUBLESHOOTING. This inspection only has procedures for checking for an open circuit on one side of the CAN branch wire.

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 FOR OPEN IN ONE SIDE OF BRANCH WIRE (SKID CONTROL ECU)

(a) Disconnect the A21 skid control ECU connector.

(b) Select "CAN Bus Check" on the Techstream.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (MAIN BODY ECU)
A -- Continue to next step.

3. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (SKID CONTROL ECU BRANCH WIRE)

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





Standard resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (SKID CONTROL ECU)

OK -- REPLACE SKID CONTROL ECU Removal

4. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (MAIN BODY ECU)

(a) Disconnect the L11 main body ECU connector.

(b) Select "CAN Bus Check" on the Techstream.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (NO. 1 METER ECU)
A -- Continue to next step.

5. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (MAIN BODY ECU BRANCH WIRE)

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





Standard resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (MAIN BODY ECU)

OK -- REPLACE MAIN BODY ECU

6. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (NO. 1 METER ECU)

(a) Disconnect the L10 No. 1 meter ECU connector.

(b) Select "CAN Bus Check" on the Techstream.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (AFS ECU)
A -- Continue to next step.

7. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (NO. 1 METER ECU BRANCH WIRE)

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





Standard resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (NO. 1 METER ECU)

OK -- REPLACE COMBINATION METER ASSEMBLY (NO. 1 METER ECU SUB-ASSEMBLY) Disassembly

8. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (AFS ECU)

(a) Disconnect the A37 AFS ECU connector.

(b) Select "CAN Bus Check" on the Techstream.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (DISPLAY AND NAVIGATION MODULE DISPLAY)
A -- Continue to next step.

9. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (AFS ECU BRANCH WIRE)

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





Standard resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (AFS ECU)

OK -- REPLACE AFS ECU Removal

10. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (DISPLAY AND NAVIGATION MODULE DISPLAY)

NOTICE:
For vehicles without multi-display, go to "CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (INTEGRATION CONTROL AND PANEL ASSEMBLY)".

(a) Disconnect the L59 display and navigation (multi-display) connector.

(b) Select "CAN Bus Check" on the Techstream.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (INTEGRATION CONTROL AND PANEL ASSEMBLY)
A -- Continue to next step.

11. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (DISPLAY AND NAVIGATION MODULE DISPLAY BRANCH WIRE)

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





Standard resistance:





Result





B -- REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY Removal

C -- REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY Removal

D -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (DISPLAY AND NAVIGATION MODULE DISPLAY)

A -- REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY Removal

12. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (INTEGRATION CONTROL AND PANEL ASSEMBLY)

NOTICE:
For vehicles with navigation system, go to "CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (ELECTRIC POWER CONTROL ECU)".

(a) Disconnect the L35 integration control and panel connector.

(b) Select "CAN Bus Check" on the Techstream.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (ELECTRIC POWER CONTROL ECU)
A -- Continue to next step.

13. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (INTEGRATION CONTROL AND PANEL ASSEMBLY BRANCH WIRE)

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





Standard resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (INTEGRATION CONTROL AND PANEL ASSEMBLY)

OK -- REPLACE INTEGRATION CONTROL AND PANEL ASSEMBLY Removal

14. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (ELECTRIC POWER CONTROL ECU)

(a) Disconnect the A69 electric power control ECU connector.

(b) Select "CAN Bus Check" on the Techstream.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (AIR CONDITIONING AMPLIFIER BRANCH WIRE)
A -- Continue to next step.

15. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (ELECTRIC POWER CONTROL ECU)

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





Standard resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (ELECTRIC POWER CONTROL ECU)

OK -- REPLACE ELECTRIC POWER CONTROL ECU

16. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (AIR CONDITIONING AMPLIFIER BRANCH WIRE)

(a) Disconnect the L77 air conditioning amplifier connector.





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

Standard resistance:





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (AIR CONDITIONING AMPLIFIER)

OK -- REPLACE AIR CONDITIONING AMPLIFIER Removal
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