Open in One Side of CAN Branch Line
NETWORKING: 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 "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
*: w/ Navigation System
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 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 FOR OPEN IN ONE SIDE OF BRANCH WIRE (DISPLAY AND NAVIGATION MODULE DISPLAY)
HINT
For vehicles without the navigation system, go to "Check for Open in One Side of Branch Wire (Center Airbag Sensor)".
(a) Disconnect the F47 display and navigation module display connector.
(b) Select "CAN Bus Check" on the Techstream Diagnosis System.
Result
B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (CENTER AIRBAG SENSOR)
A -- Continue to next step.
3. 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:
Text in Illustration
NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (DISPLAY AND NAVIGATION MODULE DISPLAY)
OK -- REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY Removal
4. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (CENTER AIRBAG SENSOR)
(a) Disconnect the E47 center airbag sensor connector.
(b) Select "CAN Bus Check" on the Techstream Diagnosis System.
Result
B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (AIR CONDITIONING AMPLIFIER)
A -- Continue to next step.
5. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (CENTER AIRBAG SENSOR BRANCH WIRE)
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CENTER AIRBAG SENSOR)
OK -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY Removal
6. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (AIR CONDITIONING AMPLIFIER)
(a) Disconnect the E35 air conditioning amplifier connector.
(b) Select "CAN Bus Check" on the Techstream Diagnosis System.
Result
B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (MAIN BODY ECU)
A -- Continue to next step.
7. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (AIR CONDITIONING AMPLIFIER BRANCH WIRE)
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (AIR CONDITIONING AMPLIFIER)
OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal
8. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (MAIN BODY ECU)
(a) Disconnect the E3 main body ECU (cowl side junction block LH) connector.
(b) Select "CAN Bus Check" on the Techstream Diagnosis System.
Result
B -- CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (NETWORK GATEWAY ECU BRANCH WIRE)
A -- Continue to next step.
9. 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:
Text in Illustration
NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (MAIN BODY ECU)
OK -- REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)
10. CHECK FOR OPEN IN ONE SIDE OF BRANCH WIRE (NETWORK GATEWAY ECU BRANCH WIRE)
(a) Disconnect E31 network gateway 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 BRANCH WIRE OR CONNECTOR (NETWORK GATEWAY ECU)
OK -- REPLACE NETWORK GATEWAY ECU Removal