System Description

1. Vehicle position tracking methods 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 Global Positioning System (GPS) (satellite) navigation. Both navigation methods are used in conjunction with each other.
   Fig 1: Vehicle Position Tracking Procedure Chart

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   VEHICLE POSITION TRACKING CHART
   
   

   Operation	Description
   Vehicle Position Calculation	Navigation ECU calculates current vehicle position (direction and current position) using direction deviation signal from gyro sensor and the running distance signal from vehicle speed sensor. Then driving route is created.
   Map Display processing	Navigation ECU displays vehicle track 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 GPS unit is compared with vehicle position and running track data. If position is widely different, GPS measurement position is used.
   Distance Correction	Running distance signal from vehicle speed sensor includes error 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 places where the GPS radio wave cannot receive a signal. When only autonomous navigation is used, however, the mapping accuracy may slightly decline.

   Fig 2: Identifying GPS Satellite, Autonomous Navigation And GPS Wave Navigation

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. 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.

   2. Vehicle speed sensor

      Used to calculate the vehicle running distance.

3. GPS navigation (Satellite navigation) This method detects the absolute vehicle position using a radio wave from a GPS satellite.

   HINT:

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

   Fig 3: GPS Navigation (Satellite Navigation)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   GPS NAVIGATION REFERENCE CHART
   
   

   Number of satellites	Measurement	Description
   2 or less	Measurement impossible	Vehicle position cannot be obtained because number of satellites is not enough.
   3	2-dimensional measurement is possible	Vehicle position is obtained based on current longitude and latitude (this is less precise than 3-dimensional measurement).
   4	3-dimensional measurement is possible	Vehicle position is obtained on current based longitude, latitude and altitude.

4. 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 to the most appropriate road.

   Fig 4: Driving Route Display

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   HINT:

   • Do not disassemble any part of the navigation ECU.
   • Do not apply oil to the navigation ECU.
   • Do not insert anything but a DVD into the navigation ECU.
   CAUTION: Do not look directly at the navigation system's laser pickup. Be sure to only operate the navigation as instructed.

1. 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.

   Fig 5: Measuring Voltage Ratio Using Touch Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. What is AVC-LAN

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

   Fig 6: Communication Diagram Between Radio Receiver And Stereo Component Amplifier

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Purpose:

   Recently, car audio systems have rapidly developed and functions has vastly changed. The conventional car audio system is being integrated with multimedia interfaces similar to those in navigation systems. At the same time, customers are demanding higher quality audio systems. The following is a brief overview of the standardization. The 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:

      • When a short circuit or circuit breakdown occurs in the AVC-LAN circuit, the audio system does not operate normally due to the communication cutoff.
      • If an audio system is equipped with a navigation system, the multi-display unit acts as the master unit.
      • The radio receiver provides resistance to make communication possible.
      • Car audio systems with AVC-LAN circuits have diagnostic functions.
      • Each component has a specified number (3-digit) called a physical address. Each function has a number (2-digit) called a logical address.

1. Components of the navigation system communicate with each other through the AVC-LAN.
2. The radio receiver has a of 60 to 80 Ω, which is necessary for transmitting the communication. This is essential for communication.

1. The navigation system has a diagnostic function (the result is indicated on the master unit).
2. A 3-digit hexadecimal component code (physical address) is allocated to each component on the AVC-LAN. Using this code, the component in the diagnostic function can be displayed.
3. if a short circuit or open circuit occurs in the AVC-LAN circuit, communication is interrupted and the audio system will stop functioning.

1. BLUETOOTH is a new 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 handsfree function with the cellular phone in a pocket or bag.

   HINT:

   *: Some versions of BLUETOOTH capable cellular phones may not function with this vehicle.

   NOTE: The communication performance of BLUETOOTH may vary depending on obstructions or radio wave conditions between communication devices, electromagnetic radiation, communication device sensitivity, or antenna capacity.
   Fig 7: Identifying Bluetooth Trademark

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   Fig 8: Identifying Multi-Display, Cellular Phone And Cellular Tower

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Titles for each unit below are stated in the following order: part name (physical address) [name indicated by DTC].

1. MULTI-DISPLAY (physical address: 110) [EMV]

   Logical address: 01 (Communication control) 

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification	See Page
   D5	Absence of registration unit	Device that sub-code shows is (was) disconnected from system when turning ignition switch to ACC or ON Communication condition with device that code shows cannot be obtained when system starts	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   D8	No response for connection check	Device indicated by subcode is (was) disconnected from system after system start	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   D9	Last mode error	Device (for audio visual system) that had functioned before system stopped is (was) disconnected from system when ignition switch is (was) on ACC or ON	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   DA	No response against ON / OFF command	No response when changing mode (audio and visual mode change). Detected when sound and image do not change by switch operation	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   DB	Mode status error	This code detects dual alarm	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   DC	Failure in transmission	This code indicates transmission failure to device indicated by the sub-code NOTE: This DTC may have no direct relationship with malfunction	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   DE	Slave reset	This code is stored when slave device has been disconnected after system start	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   E2	ON / OFF Instruction Parameter Error	Error is detected in ON / OFF control command from multi-display	Replace multi-display	-
   E3	Registration Request Transmission	Registration request command is output from slave component By reception of connection check instruction, Registration request command is output from sub-master component	Since this DTC is provided for engineering, it may be detected when no actual failure exists	-
   21	ROM error	This code is output when malfunction exists in ROM	Replace multi-display	-
   22	RAM error	This code is output when malfunction exists in RAM	Replace multi-display	-

   Logical address: 21 (SW) 

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification
   10	Panel switch error	The panel switch detection circuit has a failure	Replace multi-display
   11	Touch switch error	The touch switch detection circuit has a failure	Replace multi-display

2. NAVIGATION ECU (Physical address: 178) [NAVI]

   HINT:

   Methods used to verify the cause of the problem are listed in order of probability in the verification column.

   Logical address: 01 (Communication control)

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification	See Page
   D6	No master	When either of following conditions is met: Device that stores (stored) the code has (had) been disconnected when ignition switch is on ACC or ON Master device has (had) been disconnected when this code is stored	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) AVC-LAN circuit (radio receiver assembly - stereo component amplifier assembly) AVC-LAN circuit (navigation ECU - stereo component amplifier assembly) Power source circuit (navigation ECU) Replace multi-display Replace navigation ECU	-
   D7	Connection check error	When either of following conditions is met: Device that stored this code has (had) been disconnected after system starts (started) Master device has (had) been disconnected when this code is (was) stored	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) AVC-LAN circuit (radio receiver assembly - stereo component amplifier assembly) AVC-LAN circuit (navigation ECU - stereo component amplifier assembly) Power source circuit (navigation ECU) Replace multi-display Replace navigation ECU	-
   DC	Transmission error	Device stores fact that transmission to device indicated by sub-code) has failed	Inspection for device indicated by sub-code (refer to the inspection list for the device indicated by the sub-code)	Refer to step 9
   DD	Master reset	When device that should be master has been disconnected after system starts	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Replace multi-display	-
   DF	Master error	When device with display fails and master is switched to audio device Also when communication error between sub master (audio) and master occurs, this code is stored	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Replace multi-display	-
   E0	Registration complete indication error	When "Registration complete" command from master device cannot be received	This code will be detected when signal receiving time is delayed	-
   E2	ON / OFF indication parameter error	When command for ON / OFF control from the master device has problem	Replace multi-display	-
   E3	Registration demand transmission	When registration request command from slave device is output, or when registration request command is output by receiving connection confirmation command from sub master device	-	-
   E4	Multiple frame incomplete	When multiple frame transmission ends incomplete	-	-

   HINT:

   Methods used to verify the cause of the problem are listed in order of probability in the verification column.

   Logical address: 58 (Navigation)

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification
   10	Gyro error	Ground short, power supply short, or open circuit in gyro signal, gyro failure	Inspect gyro error Replace GPS antenna Replace navigation ECU
   42	Map disc read error	Player error Scratches or dirt on disc Access to an invalid address due to software error	Inspect map disc read error Replace map disc Replace navigation ECU
   43	SPD signal error	Difference between GPS speed and SPD pulse is detected	Inspect speed signal error Speed signal circuit (navigation ECU-combination meter) Replace navigation ECU
   44	Player error	Malfunction of player continues for certain length of time	Replace navigation ECU

   HINT:

   Methods used to verify the cause of the problem are listed in order of probability in the verification column.

   Logical address: 80 (GPS)

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification
   10	GPS receiver error	Operation error of GPS receiver is detected	At outdoor site with clear view, operate to display GPS data. If GPS mark is not properly displayed after 15 min. or more, replace navigation ECU
   40	GPS antenna error	Open condition of GPS antenna is detected (open circuit, connection failure of connectors, etc.)	Replace GPS antenna Replace navigation ECU
   41	Power supply error of GPS antenna	Abnormal voltage of GPS antenna cable or short circuit is detected	Replace GPS antenna Replace navigation ECU
   45	Gyro error	Readout cannot be performed because temperature around player's pickup (reading part) is too high	With ignition switch OFF, leave in cool shaded place for while and recheck Replace navigation ECU

3. RADIO RECEIVER ASSEMBLY (Physical address: 190) [AUDIO H/U]

   HINT:

   Methods used to verify the cause of the problem are listed in order of probability in the verification column.

   Logical address: 01 (Communication control)

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification	See Page
   D5	Absence of registration unit	Device that subcode shows is (was) disconnected from system when turn the ignition switch to ACC or ON position Communication condition with device that code shows cannot be obtained when system starts	Inspection for device indicated by sub-code (refer to inspection list for the device indicated by sub-code)	Refer to step 9
   D6	No master	When either following condition meets Device that stores (stored) code has (had) been disconnected when ignition switch is ACC Master device has (had) been disconnected when this code is stored	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Power source circuit (radio receiver assembly) Replace multi-display Replace radio receiver assembly	-
   D7	Connection check error	When either the following condition meets Device that stored this code has (had) been disconnected alter system starts (started) Master device has (had) been disconnected when this code is (was) stored	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Power source circuit (radio receiver assembly) Replace multi-display Replace radio receiver assembly	-
   D8	No response for connection check	Device indicated by subcode is (was) disconnected from system after system start	Inspection for device indicated by sub-code (refer to the inspection list for device indicated by sub-code)	Refer to step 9
   D9	Last mode error	Device (for audio visual system) that had functioned before system stopped is (was) disconnected from system when ignition switch is (was) in ACC or ON position	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   DA	No response against ON / OFF command	No response is identified when changing mode (audio and visual mode change) Detected when sound and image do not change by switch operation	Inspection for device indicated by code (refer to inspection list for device indicated by the subcode.)	Refer to step 9
   DB	Mode status error	This code detects dual alarm	Inspection for device indicated by sub-code (refer to the inspection list for device indicated by sub-code)	Refer to step 9
   DC	Failure in transmission	This code indicates transmission failure to device indicated by subcode NOTE: This DTC may have no direct relationship with malfunction	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   DE	Slave reset	This code is stored when slave device has been disconnected after system start	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   DC	Transmission error	Device stores fact that transmission to device indicated by sub-code has failed	Inspection for device indicated by sub-code (refer to inspection list for device indicated by subcode)	Refer to step 9
   DD	Master reset	When device that should be master has been disconnected after system starts.	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Replace multi-display	-
   DF	Master error	When device with display fails and master is switched to audio device Also when communication error between sub master (audio) and master occurs, this code is stored	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Replace multi-display	-
   E0	Registration complete indication error	When "Registration complete" command from master device cannot be received	This code will be detected when signal receiving time is delayed.	-
   E2	ON / OFF indication parameter error	When command for ON / OFF control from master device has problem	Replace multi-display	-
   E3	Registration demand transmission	When registration demand command from slave device is output, or when registration demand command is output by receiving connection confirmation command from sub master device	-	-

   HINT:

   Methods used to verify the cause of the problem are listed in order of probability in the verification column.

   Logical address: 62 (CD): 63 (CD changer)

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification
   42	Disc cannot be read	Disc cannot be read	Inspect CD If same code is detected, replace radio receiver assembly
   44	CD abnormal	Operation error in CD mechanism (except for code 10)	After clearing the DTC, check malfunction symptom If same code is detected, replace radio receiver assembly
   47	CD temperature is high	Sensor detects that CD unit temperature is high	Park vehicle in cool place. Turn the system off. After checking that temperature of radio and navigation assembly becomes sufficiently low, turn the system on in order to verify malfunction symptom If same code is detected, replace radio receiver assembly
   48	Excess current	Excess current is applied to disc player changer	Replace radio receiver assembly

   HINT:

   Methods used to verify the cause of the problem are listed in order of probability in the verification column.

   Logical address: 61 (Cassette)

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification
   40	Mechanical error of media	Malfunction due to mechanical problem, cassette tape is cut or entangled	Replace cassette tape and recheck symptom If same code is detected, replace radio receiver assembly

4. GATEWAY ECU (Physical address: 1C6) [G/W]

   HINT:

   Methods used to verify the cause of the problem are listed in order of probability in the verification column.

   Logical address: 01 (Communication control)

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification
   D4	Regular Communication Error	Component in which this code is recorded has been disconnected from system with ignition switch is ACC. Either that, or multi-display was disconnected when this code was recorded.	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - gateway ECU) AVC-LAN circuit (radio receiver assembly - multi-display) Replace multi-display Replace gateway ECU

5. STEREO COMPONENT AMPLIFIER ASSEMBLY (Physical address: 440) [DSP AMP]

   HINT:

   Methods used to verify the cause of the problem are listed in order of probability in the verification column.

   Logical address: 01 (Communication control)

   DIAGNOSTIC TROUBLE CODE CHART
   
   

   DTC	Name	Diagnosis	Verification
   D6	No master	When either following condition meets Device that stores (stored) code has (had) been disconnected when ignition switch is ACC or ON position Master device has (had) been disconnected when this code is stored	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Power source circuit (stereo component amplifier assembly) AVC-LAN circuit (radio receiver assembly - stereo component amplifier assembly) Replace multi-display 6. Replace stereo component amplifier assembly
   D7	Connection check error	When either following condition meets Device that stored this code has (had) been disconnected after system starts (started) Master device has (had) been disconnected when this code is (was) stored	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Power source circuit (stereo component amplifier assembly) AVC-LAN circuit (radio receiver assembly - stereo component amplifier assembly) Replace multi-display Replace stereo component amplifier assembly
   DC	Transmission error	Device stores fact that transmission to device indicated by sub-code has failed	Inspection for device indicated by sub-code (Refer to inspection list for device indicated by subcode)
   DD	Master reset	When device that should be master has been disconnected after system starts	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Replace multi-display
   DF	Master error	When device with display fails and master is switched to audio device Also when communication error between sub master (audio) and master occurs, this code is stored	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Replace multi-display
   E0	Registration complete indication error	When "Registration complete" command from master device cannot be received	This code will be detected when signal receiving time is delayed
   E1	Voice processing device ON error	When AMP device records that AMP output does not function even while source device operates	Power source circuit (multi-display) AVC-LAN circuit (radio receiver assembly - multi-display) Replace multi-display
   E2	ON / OFF indication parameter error	When command for ON / OFF control from master device has problem	Replace multi-display
   E3	Registration demand transmission	When registration demand command from slave device is output, or when registration demand command is output by receiving connection confirmation command from sub master device	-
   E4	Multiple frame incomplete	When multiple frame transmission ends incomplete	-

HINT:

Methods used to verify the cause of the problem are listed in order of probability in the verification column.