Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Open in One Side of Bus 4 Branch Line

DESCRIPTION

If an ECU or sensor is not displayed on the CAN Bus Check screen of the Techstream and some ECUs and sensors repeatedly appear and disappear from the screen when the CAN main bus lines are normal (there is no open, short, short to +B or short to GND in the main bus lines), there may be an open circuit in either of the lines in a CAN branch.

HINT:

If some ECUs and sensors repeatedly appear and disappear from the CAN Bus Check screen, communication between the normal ECUs (sensors) and the Techstream may be affected by the incomplete signals that are output from the ECU that has an open circuit in either of the lines in its CAN branch. In this case, the CAN branch lines for the ECUs and sensors that repeatedly appear and disappear from the screen are normal and the ECU that is not displayed on the screen may be the main cause of the problem (this ECU may have an open circuit in either of the lines in its CAN branch).

CAUTION / NOTICE / HINT

HINT:

Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

(a) Based on the vehicle equipment and specifications, confirm the systems that use CAN communication.

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(b) Using the Techstream, select and perform the CAN bus check.

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(c) Observe the screen for approximately 2 minutes to check the ECUs and sensors that are not displayed on the screen and also those that repeatedly appear and disappear from the screen.

(d) Check the applicable communication stop mode for the ECU or sensor that is not displayed on the screen.

NEXT

GO TO CORRESPONDING COMMUNICATION STOP MODE