Navigation System System Description

System Check Mode Display

1. Device Names and Hardware Address / *1
   

   HINT:

   1. Registered device names are displayed below.
      
   2. If a device name is unknown to the system, its physical address is shown instead.
      
      

      Address No.	Name	Address No.	Name
      110	EMV	120	AVX
      128	1DIN TV	140	AVN
      144	G-BOOK	178	NAVI
      17C	MONET	190	AUDIO H/U
      1AC	CAMERA-C	1B0	Rr-TV
      1C0	Rr-CONT	1C2	TV-TUNER2
      1C4	PANEL	1C6	G/W
      1C8	FM-M-LD	1D8	CONT-SW
      1EC	BODY	1F0	RADIO TUNER
      1F1	XM	1F2	SIRIS
      230	TV-TUNER	240	CD-CH2
      250	DVD-CH	280	CAMERA
      360	CD-CH1	3A0	MD-CH
      17D	TEL	440	DSP-AMP
      530	ETC	5C8	MAYDAY
      1A0	DVD-P	1D6	CLOCK
      1F4	RSA	1F6	RSE
      480	AMP	-	-

2. Check Result / *2
   
   

   HINT:

   Result codes for all devices are shown below.

   
   

   Result	Meaning	Action
   OK	Device did not respond with DTC (excluding communication DTCs from the AVC-LAN)	-
   EXCH	Device responds with "replace" type DTC	Check DTC in "Unit Check Mode" and replace device
   CHEK	Device responds with "check" type DTC	Check DTC in "Unit Check Mode"
   NCON	Device was previously present, but does not respond in diagnostic mode	Check power supply wire harness of device Check AVC-LAN of device
   Old	Device responds with "old" type DTC	Check DTC in "Unit Check Mode"
   NRES	Device responds in diagnostic mode, but gives no DTC information	Check power supply wire harness of device Check AVC-LAN of the device

3. Code Clear / *3
   Present DTCs are cleared.
   

4. Memory Clear / *4
   Present and past DTCs and registered connected device names are cleared.
   

Diagnosis Menu Display

HINT:

Each item is grayed out or not displayed based on the device settings.

Unit Check Mode Screen

LAN Monitor (Original) Screen

HINT:

Check results of all the devices are displayed.

LAN Monitor (Individual) Screen

Vehicle Signal Check Mode Screen

HINT:

1. Only items sending a vehicle signal will be displayed.
   
2. This screen is updated once per second when input signals to the vehicle are changed.
   

Navigation Check MENU Screen

HINT:

Each item is grayed out or not displayed based on the device settings.

GPS Information Screen

1. Satellite information / *1
   Information from a maximum of 12 satellites is displayed on the screen. This information includes the target GPS satellite number, elevation angle, direction and signal level.
   

2. Receiving condition / *2
   
   

   (DENSO made)

   Display	Contents
   T	System is receiving a GPS signal, but is not using it for location
   P	System is using the GPS signal for location
   -	System cannot receive a GPS signal

   
   

   (AISIN made)

   Display	Contents
   01H	System cannot receive GPS signal
   02H	System is tracing satellite
   03H	System is receiving GPS signal, but is not using it for location
   04H	System is using GPS signal for location

3. Measurement information / *3
   
   

   Display	Contents
   2D	2-dimensional location method is being used
   3D	3-dimensional location method is being used
   NG	Location data cannot be used
   Error	Reception error has occurred
   -	Any other state

4. Position information / *4
   
   

   Display	Contents
   Position	Latitude and longitude information on current position is displayed

5. Data information / *5
   
   

   Display	Contents
   Date	Date / time information obtained from GPS signal is displayed in Greenwich Mean Time (GMT). Last 4 digits are displayed.

Vehicle Signal Check Screen

HINT:

Signals are updated once per second only when vehicle sensor signals are changed.

Parts Information Screen

Memory Copy / Paste Screen

HINT:

1. This function cannot be used on some vehicles.
   
2. When using this function, perform the "Color Bar Check" and "Microphone Check".
   
3. "Color Bar Check" (Click here).
   
4. "Microphone Check" (Click here).
   

Vehicle position tracking methods.

1. It is essential that the navigation system correctly tracks the current vehicle position and displays it on the map. There are 2 methods to track the current vehicle position: autonomous (dead reckoning) and GPS* (satellite) navigation. Both tracking methods are used in conjunction with each other.
   

   HINT:

   *: GPS (Global Positioning System)

   
   
   1. 
      
      
      
      

      Operation	Description
      Vehicle Position Calculation	Navigation ECU calculates current vehicle position (direction and current position) using direction deviation signal from vehicle speed sensor and creates driving route.
      Map Display Processing	Navigation ECU displays vehicle tracking on map by processing vehicle position data, vehicle running track, and map data from map disc.
      Map Matching	Map data from map disc is compared to vehicle position and running track data. Then, vehicle position is matched with nearest road.
      GPS Correction	Vehicle position is matched to position measured by GPS. Then, measurement position data from the GPS is compared with vehicle position and running track data. If position is very different, GPS measurement position is used.
      Distance Correction	Running distance signal from vehicle speed sensor includes errors caused by tire wear and slippage between tires and road surface. Distance correction is performed to account for this. Navigation ECU automatically offsets running distance signal to make up for difference between it and distance data of map. Offset is automatically updated.

      HINT:

      The combination of autonomous and GPS navigation makes it possible to display the vehicle position even when the vehicle is in a place where GPS radio waves cannot be received. When only autonomous navigation is used, however, the mapping accuracy may slightly decline.

      
      
      
      
      
      

Autonomous navigation
This method determines the relative vehicle position based on the running track determined by the gyro and vehicle speed sensors located in the navigation ECU.

1. Gyro sensor
   Calculates the direction by detecting angular velocity. It is located in the radio and navigation assembly.
   

2. Vehicle speed sensor
   Used to calculate the vehicle running distance.
   

GPS navigation (Satellite navigation)
This method detects the absolute vehicle position using GPS radio waves.

HINT:

GPS satellites were launched by the U.S. Department of Defense for military purposes.

Map matching
The current driving route is calculated by autonomous navigation (according to the gyro sensor and vehicle speed sensor) and GPS navigation. This information is then compared with possible road shapes from the map data in the map disc and the vehicle position is set onto the most appropriate road.

The navigation ECU uses a laser pickup to read the digital signals recorded on a DVD.

CAUTION:

Because the navigation system uses an invisible laser beam, do not look directly at the laser pickup. Be sure to only operate the navigation as instructed.

HINT:

1. Do not disassemble any part of the navigation ECU.
   
2. Do not apply oil to the navigation ECU.
   
3. Do not insert anything but DVDs into the navigation ECU.
   

Touch switch
Touch switches are touch-sensitive (interactive) switches operated by touching the screen. When a switch is pressed, the outer glass bends in to contact the inner glass at the pressed position. By doing this, the voltage ratio is measured and the pressed position is detected.

What is AVC-LAN?
AVC-LAN, an abbreviation for "Audio Visual Communication Local Area Network", is a united standard developed by the manufacturers in affiliation with Toyota Motor Corporation. This standard pertains to audio and visual signals as well as switch and communication signals.

Purpose:
Recently, car audio systems have rapidly developed and the functions have vastly changed. The conventional car audio system is being integrated with a multimedia interface similar to those in navigation systems. At the same time, customers are demanding higher quality from their audio systems. This is an overview of the AVC-LAN standardization. Its specific purposes are as follows:

1. To solve sound problems, etc., caused by using components of different manufacturers through signal standardization.
   

2. To allow each manufacturer to concentrate on developing products they do best. From this, reasonably priced products can be produced.
   

   HINT:

   1. If a +B or GND short is detected in the AVC-LAN circuit, communication is interrupted and the audio system will stop functioning.
      
   2. If an audio system is equipped with a navigation system, the multi-display unit acts as the master unit. If a navigation system is not equipped, the audio head unit acts as the master unit instead.
      
   3. The radio receiver assembly provides resistance to make communication possible.
      
   4. A car audio system with an AVC-LAN circuit has a diagnostic function.
      
   5. Each component has a specified number (3-digit) called a physical address. Each function has a number (2-digit) called a logical address.
      
   6. Components of the navigation system communicate with each other via the AVC-LAN.
      

BLUETOOTH is a wireless connection technology that uses the 2.4 GHz frequency band. This makes it possible to remotely connect a cellular phone (BLUETOOTH-capable phone) to the multi-display (BLUETOOTH system is built-in), and use a hands-free function with the cellular phone even when it is in your pocket or bag.

HINT:

Some versions of BLUETOOTH may vary depending on obstructions or radio wave conditions between communication devices, electromagnetic radiation, communication device sensitivity, or antenna capacity.

If a symptom is applicable to any of the following, it is not a malfunction.

The following symptoms are not a malfunction, but are caused by errors inherent in the GPS, gyro sensor, speed sensor, and navigation ECU.

1. The current position mark may be displayed on a nearby parallel road.
   





2. Immediately after a fork in the road, the current vehicle position mark may be displayed on the wrong road.
   





3. When the vehicle turns right or left at an intersection, the current vehicle position mark may be displayed on a nearby parallel road.
   





4. When the vehicle is transported, such as on a ferry, and the vehicle itself is not running, the current vehicle position mark may be displayed in the position where the vehicle was until a measurement is performed by the GPS.
   





5. When the vehicle runs on a steep hill, the current vehicle position mark may deviate from the correct position.
   





6. When the vehicle makes a continuous turn of 360°, 720°, 1,080°, etc., the current vehicle position mark may deviate from the correct position.
   





7. When the vehicle moves erratically, such as during constant lane changes, the current vehicle position mark may deviate from the correct position.
   





8. When the engine switch is turned on (ACC) / off while on a turntable before parking, the current vehicle position mark may not point in the correct direction. The same will occur when the vehicle comes out of parking.
   





9. When the vehicle is driven on a snowy road or mountain path with chains installed or a spare tire installed, the current vehicle position mark may deviate from the correct position.
   





10. When a tire is changed, the current vehicle position mark may deviate from the correct position.
    

    HINT:

    1. The diameter of the tire may change, causing a speed sensor error.
       
    2. Performing the "tire change" in calibration mode will allow the system to correct the current vehicle position faster.