Body and Frame: Description and Operation
Servicing the electrical system
1. Prior to servicing the electrical system, be sure to turn off the ignition switch and disconnect the battery ground cable.
NOTE:
In the course of MFI or ELC system diagnosis, when the battery cable is removed, any diagnostic code retained by the computer will be cleared.
Therefore, if necessary, record the diagnostic codes before removing the battery cable.
2. Secure the wiring harnesses by using clamps so that there is no slack. However, for any harness which passes to the engine or other vibrating parts of the vehicle, allow some slack within a range that does not allow the engine vibrations to cause the harness to come into contact with any of the surrounding parts, and then secure the harness by using a clamp.
3. If any section of a wiring harness interferes with the edge of a part or a corner, wrap the section of the harness with tape or something similar in order to protect it from damage.
4. When installing any of the vehicle parts, be careful not to pinch or damage any of the wiring harnesses.
5. The sensors, relays, and electrical parts must never be subjected to strong shocks. Do not allow them to fall and do not throw them when handling.
6. The electronic parts used in the computer, relays, etc. are readily damaged by heat. If there is a need for service operations that may cause the temperature to exceed 80°C (176°F), remove the electronic parts beforehand.
7. Loose connectors could be troubled. Make sure that connectors are connectors securely.
8. When removing a connector, be sure to pull only the connector, not the harness.
9. Remove connectors which have catched by pressing in the direction indicated by the arrows in the illustration.
10. Connect connectors which have catched by inserting the connectors until a "snap" noise is heard.
11. When using a circuit tester to perform continuity or voltage checks on connector terminals, insert the test probe from the harness side.
If the connector is a sealed connector, insert the test probe through the hole in the rubber cap for the electrical wires, being careful not to damage the insulation of the wires; continue to insert the test probe until it contacts the terminal.
12. In order to avoid overloading the wiring, take the electrical current load of the optional equipment into consideration, and determine the appropriate wire size.
Installation of radio equipment
The electronic control system has been designed so that external radio waves will not interfere with their operation.
However, if the antenna or cable of the amateur transceiver is routed near the computers, it may affect the operation of the computers, even if the output of the transceiver is no more than 25W.
To protect each of the computers from interference by transmitter (hum, transceiver, etc.) the following should be observed.
1. Install the antenna on the roof or rear bumper.
2. Because radio waves are emitted from the coaxial cable of the antenna, keep it 200mm (8in.) away from the computers and the wiring harness. If the cable must cross the siring harness, route it so that it runs at right angles to the wiring harness.
3. The antenna and the cable should be well matched, and the standing-wave ratio* should be kept low.
4. A transmitter having a large output should not be installed in the vehicle.
5. After installation of transmitter, run the engine at idle, emit radio waves from the transmitter and make sure that the engine is not affected.
*Standing-wave ratio
STANDING-WAVE RATIO If an antenna and a cable having different impedances are connected, the input impedance Zi will vary in accordance with the length of the cable and the frequency of the transmitter, and the voltage distribution will also vary in accordance with the location.
The ratio between this maximum voltage and minimum voltage is called the standing-wave ratio. It can also be represented by the ratio between the impedances of the antenna and the cable.
The amount of radio waves emitted from the cable increases as the standing-wave ratio increases, and this increases the possibility of the electronic components being adversely affected.
