Can Communication System Open In One Side Of Can Branch Line

Power Source Network. Corolla. Zre142 Aze141
Networking. Corolla. Zre142 Aze141

DESCRIPTION

INSPECTION PROCEDURE

CHECK FOR OPEN IN ONE SIDE OF CAN NO. 1 BUS BRANCH WIRE

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


DESCRIPTION

If some ECUs and sensors are not displayed the "CAN Bus Check" on screen of the Techstream and some ECUs and sensors repeatedly appear and disappear from the screen when the CAN main bus wires are normal (there is no open, short, short to B+, or short to GND in the main bus wires), there may be an open circuit in either of the CAN branch wires.
HINT:
If some ECUs and sensors repeatedly appear and disappear the "CAN Bus Check" from 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 its CAN branch wires. In this case, the CAN branch wires 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 its CAN branch wires).

Symptom
Trouble Area
2 or more ECUs and/or sensors do not appear on the Techstream "CAN Bus Check" screen.
One side of the CAN branch wire is open, or output signals are incomplete.
  1. Skid control ECU
  2. Steering angle sensor
  3. Yaw rate sensor
  4. Power steering ECU
  5. Air conditioning amplifier
  6. Main body ECU
  7. Center airbag sensor assembly
  8. ECM
  9. Combination meter
  10. Accessory gateway

INSPECTION PROCEDURE

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.
1.CHECK FOR OPEN IN ONE SIDE OF CAN NO. 1 BUS BRANCH WIRE

  1. Confirm the systems (ECUs and sensors), which use CAN communication, equipped on the vehicle (COROLLA_ZRE142 RM000000WIB0BUX.html).

  1. Using the Techstream, select and perform "CAN Bus Check" (COROLLA_ZRE142 RM000000WIB0BUX.html).

  1. Observe the screen for approximately 1 minute to check the ECUs and sensors that are not displayed on the screen and also those that repeatedly appear and disappear from the screen.

  1. Check that the ECUs and sensors, which are connected to the ECUs or sensors that are not displayed on the screen.

  1. Check that the ECUs and sensors, which repeatedly appear and disappear the "Bus Check" screen, are constantly displayed.


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