CAN Communication System - Diagnostics: Overview Toyota Matrix E130

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1. HANDLING PRECAUTIONS ON STEERING SYSTEM Care must be taken when replacing parts. Incorrect replacement could affect the performance of the steering system and result in hazardous driving.
2. HANDLING PRECAUTIONS ON SRS AIRBAG SYSTEM This vehicle is equipped with an SRS (Supplemental Restraint System), such as the driver airbag and front passenger airbag. Failure to carry out service operation in the correct sequence could cause the SRS to unexpectedly deploy during servicing, possibly leading to a serious accident. Before servicing (including removal or installation of parts, inspection or replacement), be sure to read the precautionary notice for the supplemental restraint system (see «SUPPLEMENTAL RESTRAINT SYSTEM»(ref-225923-S25208464262006032300000) ).
3. WIRE HARNESS REPAIR After repairing the wire bus line with solder, wrap the repaired part with vinyl tape. NOTE: The CANL bus line and CANH bus line must be installed together all the time. When installing, make sure to twist them. The difference in length of the CANL bus line and CANH bus line should be within 100 mm (3.93 in.). Untwisted parts around the connector should be within 80 mm (3.15 in.). Do not perform bypass wiring between the connectors. NOTE: If you perform bypass wiring, the characteristic of the twisted wire harness will be lost.
4. CONNECTOR HANDLING When inserting tester probes into a connector, insert them from the back of the connector. If it is impossible to check resistance from the back of the connector, use a repair wire to check it.

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SYSTEM DESCRIPTION

1. BRIEF DESCRIPTION CAN (Controller Area Network) is a serial data communication system for real time application. It is a vehicle multiplex communication system which has a high communication speed (500 kbps) and the ability to detect malfunctions. The CAN performs the communication based on the differential voltage by pairing the CANH bus line and CANL bus line. This vehicle uses the CAN communication system for communication between the following ECU and sensors in the ABS with EBD & BA & TRC & VSC system. The CAN has two resistors of 120 ohm that are necessary for communication to the main bus line.
2. DEFINITION OF TERMS Main bus line Main bus line is a wire harness between the two terminus circuits on the bus (communication line). This is the main bus in the CAN communication system. Sub bus line Sub bus line is a wire harness which diverges from the main bus line, which is the main bus of the CAN bus, to an ECU or sensor.
3. ECU OR SENSORS WHICH COMMUNICATE THROUGH THE CAN COMMUNICATION SYSTEM Skid Control ECU Steering Sensor Yaw Rate Sensor
4. DIAGNOSTIC CODES FOR THE CAN COMMUNICATION SYSTEM DTCs for the CAN communication system are as follows: U0073/94, U0123/62, U0124/95, U0126/63
5. REMARKS FOR TROUBLESHOOTING Trouble in the CAN bus (communication line) can be checked from the DLC3 (except a wire break other than in the DLC3 sub bus line). By using the hand-held tester, DTCs for the CAN communication system can be checked through the DTC ISO 9141K-Line. The CAN communication system cannot detect trouble in the DLC3 sub bus line even though the DLC3 is also connected to the CAN communication system.