How to Troubleshoot the Navigation System

General Operation
Refer to the Navigation System Manual for the navigation system operating procedures.

Symptom Diagnosis
Certain circumstances and system limitations will result in occasional vehicle positioning errors. Some customers 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 customers 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 signal) can cause some discrepancies between the vehicle's actual position and the indicated vehicle 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:
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    Continuous tire slippage on a slippery surface
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    Driving with snow chains mounted
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    Abnormal tire pressure
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    Incorrect tire size
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    Frequent lane changes across a wide highway
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    Continuous driving on a straight or gently curving highway
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    Very bumpy roads
  • Tolerances in the system and map inaccuracies sometimes limit how precisely the vehicle position is indicated. Examples of this include:
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    Driving on roads not shown on the map (map matching is not possible)
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    Driving on a road that winds in one direction, such as a loop bridge, an interchange, or a spiral parking garage
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    Driving on a road with a series of sharp hair-pin turns
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    Driving near a gradual highway exit or transition
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    Driving on one of two close parallel roads
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    Making many 90 degree turns

Global Positioning System (GPS) Limitations
The GPS cannot detect the vehicle's position during the following instances:
  • For the first 5 to 10 minutes after reconnecting the battery (This 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 cellphones placed near the navigation system.
The accuracy of GPS is reduced during these instances:
  • Metallic window tinting above the GPS antenna.
  • When only two satellite signals can be received (Three satellite signals are required for accurate positioning).
  • When the satellite control centers are experiencing problems.
  • When driving near high tension power lines.
  • 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 cellphones placed near the navigation system.

Muting Logic
Whenever the navigation system is giving guidance all the front speakers are muted. When the voice control system is being used, all of the speakers are muted.

LCD Display Unit Limitations
  • In cold temperatures, the display may stay dark for the first 2 or 3 minutes until it warms up.
  • When the display is too hot because of direct summer sunlight, it will remain dark until the temperature drops (You may see an error message displayed stating this fact).
  • When the humidity is high and the interior temperature is low, the display may appear cloudy. The display will clear up after some use.
  • Fingerprints on the touch panel may sometimes be noticeable because of the panel's low-reflection coating. Clean the screen with a soft, damp cloth. You may use a mild cleaner intended for eye glasses or computer screens. To avoid scratching the panel, do not rub too hard, or use abrasive cleaners or shop towels.
  • The touch panel consists of a touch sensitive resistive membrane covering the display. Unlike previous systems, you must actually ‘‘touch'' the display to activate it. Never use hard or sharp implements to operate the screen because you risk damaging the sensing membrane. If a touch ‘‘switch'' does not function immediately, shift your finger slightly, and touch it again.
Note: The display is unaffected by sunlight, as in previous displays.

Symptom Duplication
  • When the symptom can be duplicated, verify that it is not a characteristic of the system. Review the navigation manual and compare it to a known-good vehicle (with the same software and database), under the same conditions. If not the same, follow the self-diagnostic procedures and the appropriate troubleshooting procedures.
  • When the symptom does not reappear or only reappears intermittently, ask the customer about the conditions when the symptom occurred.
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    Ask the customer to demonstrate the problem.
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    Try to establish possible user error or misunderstanding of the system.
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    Try to establish if outside interference may have been the cause.
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    Try to duplication the symptom under the same conditions the customer was experiencing.
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    Vibration, temperature extremes, and moisture (dew, humidity) are factors that are difficult to duplicate.
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    Inspect the vehicle for after-market electronic devices (vehicle locators, amps, radar detectors, etc.) that may be hidden.

Service Precautions
  • If the navigation unit needs to be replaced, inform the customer that personal information in the navigation system will be lost. If possible, have the customer record their personal information before the unit is replaced.
  • Before disconnecting the battery, make sure you have the anti-theft codes for the radio and the navigation system, and write down the radio channel presets. Also obtain any PGM-FI or transmission DTCs and freeze frame date (which will be lost when the PCM loses power).
  • When the battery is disconnected, the internal GPS clock is reset to ‘‘0:00''. The clock will reset to the correct time after the system finishes GPS initialization.
  • After reconnecting the battery, you have to wait to get the initial signal from the satellite. It will take from 10 to 45 minutes.
  • Verify map matching
  • Before returning the vehicle to the customer, enter the radio and navigation anti-theft security code, then enter the customer's radio channel presets, adjust the setup clock settings in the navigation system.

System Initialization
If for any reason, you lose power to the navigation system (like the battery was disconnected). The navigation system will require initialization. Once completed, the system will be ready to use.
This initialization requires the following:
  • GPS initialization (may not be needed depending of the length of time the system was without power)
  • Map matching to align the GPS to a location on the map

GPS initialization
Depending on the length of time the battery was disconnected, your system may require GPS initialization. If it does, the following screen appears:

If this procedure is not necessary the system proceeds directly to the Disclaimer screen. During initialization, the system searches for all available GPS satellites, and obtains their orbital information. During this procedure the vehicle should be out in the open with a clear view of the sky.
If the navigation system finds the satellites properly, this box clears, and changes to the Disclaimer screen. If within 10 minutes the system fails to locate a sufficient number of satellites to locate your position, the following screen appears.
If this is displayed, turn off the engine, then restart the vehicle. If you now see the Disclaimer screen, the GPS initialization is complete.
NOTE:

Map Matching
This part of the initialization matches the GPS coordinates with a road on the map screen. To perform this part of the procedure, ensure that the navigation system is displaying a map. Check the ‘‘GPS'' icon in the upper left corner of the screen, it should be ‘‘Green'' when the vehicle is parked outside, with the correct color labeled DVD installed in the navigation unit. Drive the vehicle on a mapped road shown on the map screen. Do not enter a destination at this time. When the name of the current road you are driving on, appears at the bottom of the screen, the entire procedure is complete. Your system is now ready to use.