Part 1

How to Troubleshoot the Navigation System

General Operation

Refer to the navigation manual for the navigation system operating procedures.

Anti-Theft Feature

The audio-navigation unit has a coded theft protection circuit. Make sure you have the anti-theft security code before:

- Disconnecting the 12 volt battery.
- Disconnecting the audio-navigation unit connector A (24P) and C (8P).
- Removing the No. B1 (15 A) fuse from the under-dash fuse/relay box.

After service, reconnect power to the audio-navigation unit, and turn the ignition switch to ON (II). Enter the 4-digit anti-theft security code, then select Done.

If the code card is lost or unavailable, you can get the code form the interactive Network (iN) using the navigation system serial number. The system serial number can easily be obtained without removing the audio-navigation unit. To get the serial number and the code, do this:

- Press and hold the MENU, MAP/GUIDE, and CANCEL buttons for 3 seconds.
- At the select diagnosis items screen, select Detail Information & Settings, select Unit Check, then ECU Info. The system runs a brief diagnosis, then the audio-navigation unit serial number is displayed at the bottom of the screen.
- Use the navigation anti-theft code inquiry option on the iN to look up the 4-digit navigation anti-theft code.

The iN may display more than one code for a given serial number. This is because serial numbers are not unique. You may have to try more than one 4-digit code. If no code is shown, or if the code(s) given do not work in the audio-navigation unit, contact the Automobile Warranty department.

Alternatively, you can find the serial number on the underside label which is located on the audio-navigation unit in the dash. When replacing the audio-navigation unit, be sure to give the customer the new anti-theft security code.

Symptom Diagnosis

Certain circumstances and system limitations may result in occasional vehicle positioning errors. Some customer's may think this indicates a problem with the navigation system when, in fact, the system is normal. Keep the following items in mind when interviewing customer's about symptoms of the navigation system.

Self-Inertial Navigation Limitations

The limitations of the self-inertial portion of the navigation system (the yaw rate sensor and the vehicle speed pulse signal) can cause discrepancies between the vehicle's actual position and the indicated vehicle's position (GPS vehicle position).

The following circumstances may cause vehicle positioning errors:

- Moving the vehicle with the engine stopped and the vehicle stopped, such as by ferry or tow truck, or if the vehicle is spun on a turn table.
- Tire slippage, changes in tire rolling diameters, and some driving situations may cause discrepancies in travel distances. Examples of this include:
- Continuous tire slippage on a slippery surface
- Driving with snow chains mounted
- Abnormal tire pressure
- Incorrect tire size
- Frequent lane changes across a wide highway
- Continuous driving on a straight or gently curving highway
- Very bumpy roads

- Tolerances in the system and map inaccuracies sometimes limit how precisely the vehicle's position is indicated. Examples of this include:
- Driving on roads not shown on the map (map matching is not possible)
- Driving on a road that winds in one direction, such as a loop bridge, an interchange, or a spiral parking garage
- Driving on a road with a series of sharp hair-pin turns
- Driving near a gradual highway exit or transition
- Driving on one of two close parallel roads
- Making many 90 degree turns

Global Positioning System (GPS) Limitations

The GPS cannot detect the vehicle's position or elevation during the following instances:

- For the first 5 to 10 minutes after reconnecting the battery (this process can take as long as 45 minutes).
- When the satellite signals are blocked by tall buildings, mountains, tunnels, large trees, inside parking structures or large trucks.
- When the GPS antenna is blocked by metallic window tinting or by an object placed above it in the vehicle. The GPS antenna requires a clear unobstructed view of the sky.
- When there is no satellite signal output (signal output is sometimes stopped for satellite servicing).
- When the satellite signals are blocked by the operation of some electronic aftermarket accessories including, but not limited to non-OEM in-dash entertainment units (radio, CD players/changers, radar detectors and theft recovery systems) and cell phones placed near the navigation system.

The accuracy of the GPS is reduced during these instances:

- Metallic window tinting above the GPS antenna.
- When only three or fewer satellite signals are received (Four satellite signals are required for accurate positioning).
- When driving near high tension power lines.
- When the satellite control centers are experiencing problems.