DESCRIPTION When the CAN bus main lines are normal (no open, short to ground, short to +B or short between lines) and there is an ECU or sensor on the "Communication Bus Check" screen that is indicated as not communicating or whose connection status on the "Communication Bus Check" screen changes intermittently, an open in one of the wires of a CAN bus branch line is suspected. HINT: If there is an ECU or sensor whose connection status changes intermittently while checking the "Communication Bus Check" screen, there may be an open circuit in one of the wires of a branch line of an ECU or sensor in the bus. If an open occurs in one of the wires of a CAN branch line, it may interfere with the communication of other ECUs or sensors resulting in an incorrect state being displayed.
CAUTION / NOTICE / HINT CAUTION: When performing the confirmation driving pattern, obey all speed limits and traffic laws. NOTICE:
PROCEDURE
(a) Based on the vehicle equipment and specifications, confirm the systems that use CAN communication. Click here (b) Connect the Techstream to the DLC3. (c) Turn the engine switch on (IG). (d) Turn the Techstream on. (e) Using the Techstream, perform "CAN Bus Check". CAN Bus Check(f) Observe the screen for approximately 2 minutes to check for ECUs and sensors that are displayed as not communicating. (g) Perform the inspection as specified in the Problem Symptoms Table for the ECUs or sensors that are not communicating.
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Toyota Avalon (XX50) 2019-2022 Service & Repair Manual > Sfi System: Diagnosis System
DIAGNOSIS SYSTEM DESCRIPTION When troubleshooting OBD II (On-Board Diagnostics) vehicles, the Techstream (complying with SAE J1978) must be connected to the DLC3 (Data Link Connector 3) of the vehicle. Various data in the vehicle's ECM (Engine Control Module) can be then read. OBD II regulations req ...
