Section 143 (Can Communication System - Diagnostics): Precaution

WARNING: This page is about a different car, the 2005 Toyota Sienna. However, it is still accessible from the selected car via links, so may be relevant.

WIRE HARNESS REPAIR
1. After repairing wire harness, wrap the repaired part with a vinyl tape.
  NOTE:
  - The CANL wire harness and CANH wire harness must be installed together all the time.
    When installing, make sure to twist them.
  - The difference in the length of the CANL wire harness and CANH wire harness should be within 100 mm (3.937 in.).
  Fig 1: wrapping Repaired Part With Vinyl Tape
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Do not perform the bypass wiring between the connectors.
NOTE: If you perform the bypass wiring, the characteristic of the twisted wire harness will be lost.

Fig 2: Identifying Wire Wrapping Precaution
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 3: Inserting Tester Probes Into Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. If it is impossible to check resistance from the back of the connector, use a repair wire to check it.
Fig 4: Checking Resistance From Back Of Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002