Can Communication System: Precaution

WARNING: This page is about a different car, the 2008 Toyota FJ Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

DISCONNECT AND RECONNECT CABLE OF NEGATIVE BATTERY TERMINAL

Before performing electronic work, disconnect the cable from the negative (-) battery terminal in order to prevent it from shorting and burning out.
When disconnecting and reconnecting the battery cable, turn the ignition switch OFF and headlight dimmer switch OFF. Then loosen the terminal nut completely. Be careful not to damage the cable or terminal.

When the battery cable is disconnected, the settings of the clock and radio, memory of DTCs, etc. are erased. Before disconnecting the battery cable, take notes of the settings and memory.

NOTE: When disconnecting the cable from the negative (-) battery terminal, initialize the following system(s) after the cable is reconnected.

Fig 1: Disconnecting Battery Negative Cable

METER/GAUGE SYSTEM REFERENCE

System Name	See procedure
Meter/gauge system	See CALIBRATION

PRECAUTION
1. Turn the ignition switch OFF before measuring the resistances of the CAN main wire and the CAN branch wire.
2. After the ignition switch is turned off, check that the key reminder warning system is not in operation.
3. Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If doors need to be opened in order to check connectors, open the doors and leave them open.
  HINT:
  
  Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
STEERING SYSTEM HANDLING PRECAUTIONS
1. Care must be taken when replacing parts. Incorrect replacement could affect the performance of the steering system and result in hazards when driving.
SRS AIRBAG SYSTEM HANDLING PRECAUTIONS
1. This vehicle is equipped with an SRS (Supplemental Restraint System) such as the driver airbag and front passenger airbag. Failure to carry out service operations in the correct sequence could cause unexpected SRS deployment during servicing and may lead 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 PRECAUTION ).
BUS LINE REPAIR
1. After repairing the bus line with solder, wrap the repaired part with vinyl tape (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
  NOTE:
  - The CANL bus line and CANH bus line must always be installed together.
  - When installing, twist them together.
  - CAN bus lines are likely to be influenced by noise if the bus lines are not twisted together.
  - The difference in length between the CANL bus line and CANH bus line should be less than 100 mm (3.937 in.).
  - Leave approximately 80 mm (3.150 in.) loose in the twisted wires around the connectors.
    
    Fig 2: Identifying Bus Line Wire Repairing Point
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Do not use bypass wiring between the connectors.
  NOTE: The feature of the twisted wire harness will be lost if bypass wiring is used.
  
  Fig 3: Identifying Precaution For Bus Line Wire Repair
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CONNECTOR HANDLING
1. When inserting tester probes into a connector, insert them from the rear of the connector.
  
  Fig 4: Inserting Tester Probes Into Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Use a repair wire to check the connector if it is impossible to check the resistance from the rear of the connector.
  
  Fig 5: Checking Connector Using Repair Wire
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002