Open in One Side of CAN Sub Bus Line (from 12/2010)

CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: Open in One Side of CAN Sub Bus Line
- Open in One Side of CAN Sub Bus 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 sub-bus line may be open. (One side of the CAN-H [sub-bus line]/CAN-L [sub-bus line] of the ECU and/or sensor is open.)





*1: w/ Navigation system

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
* The following is the troubleshooting procedure for an open circuit in either the CANH or CANL wire to an ECU (sensor).
* Perform the following inspection for the ECUs (sensors) which are not displayed on the Techstream. If a malfunction cannot be identified, then perform the following inspections for the ECUs (sensors) connected to the CAN communication system.

PROCEDURE

1. CHECK CAN BUS WIRE

(a) Disconnect the connector with terminals CANH and CANL of the ECU.





Text in Illustration





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

HINT
* This step should be repeated for each ECU (sensor) until only one (the disconnected ECU (sensor)) is missing from the CAN bus check.
* It can then be determined that this ECU has an open circuit in one of its CANH or CANL wires.

Standard:





B -- RECONNECT CONNECTOR. REPEAT THIS INSPECTION FOR OTHER ECUS (SENSORS) UNTIL ONLY ONE IS NOT DISPLAYED
A -- Continue to next step.

2. CHECK CAN BUS WIRE

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





Text in Illustration





Standard resistance:





HINT
* This is an example inspection.
* Perform this inspection for the ECU that was not displayed in the previous inspection.

NG -- REPAIR OR REPLACE ECU BUS LINE OR CONNECTOR

OK -- REPLACE ECU