Purpose of the System
The Mk-3 navigation system is a factory installed navigation system that replaces the previous Mk-2 version. The purpose of the system remains the same as previous navigation systems: To provide the driver with navigation instructions to an entered destination based on the vehicles current position and the roads available selected from a digitized road map.
The principle differences of the Mk-3 system over the previous Mk-2 are
- GPS receiver is integrated into the MK-3 computer.
- Optimized memory and faster processor resulting in faster start-up and operation.
- New split screen and magnifying feature when equipped with wide screen monitor. (software feature)
- Same navigation computer used for color board monitor or monochrome MIR display units.
The Mk-3 navigation computer is located in the left side of the vehicles trunk or cargo area. (In the case of the Z8 it is installed in the storage box behind the passenger seat.)
The navigation computer housing contains
Scheme 5
- Map CD drive
- Hardware for navigation function
- GPS receiver
- Gyro sensor
- Output for audio interface
- Output for visual display
- Cooling fan for unit (Scheme 5): Identifying MK-3 Navigation Computer
There are two different hardware versions available dependent on the angle of installation in the vehicle (horizontal or vertical). The Mk-3 is compatible with both board monitor or MIR display units.
Identification of the Mk-3 computer over the previous versions is easy due to a change in the face plate design and the elimination of the "CD-IN" LED.
Mk-3 Navigation Computer
Mk-1 and Mk-2 Navigation Computer
Identifying Integrated GPS Receiver And Gyro (Rotation) Sensor. Scheme 8
GPS (Global Positioning System) Receiver
The GPS receiver module of the previous Mk-2 system is integrated into the housing of the Mk-3 computer, further reducing the complexity and the number of components used in the system. The receiver is not serviceable.
The GPS receiver is responsible for receiving the satellite signals and providing the vehicle's position information to the navigation computer
Information provided by the GPS receiver to the navigation computer can be displayed in the service mode (see WORKSHOP HINTS ) but is not typically used in diagnosis.
Gyro (Rotation) Sensor
The navigation computer contains the electronic (piezo) Gyro sensor that detects rotation (yaw) of the vehicle as a confirmation that the vehicle is turning. The signal provided by the gyro is a mili-voltage that changes as the vehicle rotates. The navigation computer uses the input to track the vehicle along the digitized map and display the exact vehicle position.
The signal is available in the sensor test page of the service mode for diagnosis. The sensor is not a separately serviceable item and does not require calibration.
GPS Antenna
The GPS antenna is directly connected to the navigation computer via a coaxial cable. Locations of the antenna in the vehicles are as follows
| E38 | Under the rear parcel shelf. |
|---|---|
| E39 sedan | Under the rear parcel shelf. |
| E39 Sport Wagon | Behind the dashboard on the left side. |
| E46 sedan/coupe | Under the rear parcel shelf. |
| E46 Sport Wagon | Above the rear glass under the spoiler. |
| E46 Convertible | Behind the instrument cluster. |
| E52 | Left front corner behind the dashboard. |
| E53 | Above the rear glass under the spoiler. |
GPS SPECIFICATION
Display Units
Based on the particular model, the factory installed Mk-3 system is displayed using a color board monitor or on a smaller monochromatic screen (MIR).
E52 MIR (Multi Information Radio)
Identifying E52 MIR (Multi Information Radio). Scheme 9
E46/E53 Color Board Monitor
Identifying E46/E53 Color Board Monitor. Scheme 10
E38/E39 Wide Screen Color Board Monitor (phased in for E53 1/01, E46 9/01)
Identifying E38/E39 Wide Screen Color Board Monitor (Phased In For E53 1/01, E46 9/01). Scheme 11
Example of E38/E39 with Mk-3 navigation
Information/Body Bus Interface
The navigation computer is integrated into the vehicle bus system as it's main communication link with the vehicle.
Communication occurs with the following modules
- BMBT - Control inputs
- Radio - Display data
- GM - Door open
- IKE/Kombi - On-board computer data
- Telephone PSE Box - Monitor display data, mayday function
- DISplus - Coding data
PSE = Portable Support Electronics
Video/Audio Signals
The RGB video signal for all display functions of the board monitor are produced by the navigation computer graphics stage via three output signals. The Red-Green-Blue signals are direct inputs to the board monitor. The audio signals for navigation instructions to the radio are sent via two separate lines.
Identifying GPS Antenna Assembly. Scheme 13
Since a color display is not used for the MIR, the navigation information for the display is sent via a NAV bus. The NAV bus is a single dedicated line between the Mk-3 computer and the MIR. Audio signals for navigation instructions are sent to the radio via two separate lines.
Speed Signals
A speed signal is provided to the navigation computer for detection of distance traveled and vehicle speed to calculate the vehicles position on the digital map. The input is a processed signal provided by the vehicles DSC control unit.
- E46: The speed signal used is from the left rear wheel.
- E38/E39/E52/E53: The speed signal used is from the left front wheel.
Reverse Gear Input
The reverse gear input is used by the navigation computer to distinguish between the vehicle backing up or turning around.
Scheme 15
Scheme 16
- E38/E39/E52/E53: The reverse input is a high signal produced by the LCM III. (Scheme 15): Identifying Reverse Gear Input
- E46: The reverse input is a high signal supplied by a splice from the back-up lights. (Scheme 16): Identifying Reverse Input
When replacing the Mk-3 navigation computer be aware that there are two hardware variants depending on the installation position (vertical or horizontal).
The ignition should be in position 0 during removal and replacement of the computer. After installing, close all doors, hood and trunk. A bus line reset will be carried out within two minutes. Resetting allows the gyro to perform a calibration run. Do not move the car during this reset period.
The coding sequence for the Mk-3 navigation computer has been changed from the previous Mk-2. There is now an additional step (configuration) that must be done before the software can be loaded.
After resetting, a configuration signal is needed to allow the computer to load the correct software for use with a board monitor or MIR. This is performed using the DIS coding program (CD 22.0 onward) and the Navigation System operating software (CD V15.0 onward).
Note. Vehicles using the wide screen BM require CD V16.1 onward.
Scheme 17
Scheme 18
- From the DIS/MoDiC Coding /Programming select "1 ZCS Coding"
- Select the appropriate series (E46,E39,E38,E52,E53)
- Select "4 Conversion" (Scheme 17): Identifying Display "4 Conversion"
- Select "3 IKE?Kombi" (Scheme 18): Identifying Display "3 IKE?Kombi"
- Select "2 language"
- At the prompt "is the CD ROM present?" select yes, but do not install the operating software CD ROM yet.
- First select the main language and then an additional language. (i.e. English-spanish)
- Select the gender of the navigation audio voice.
- Select "automatic coding-yes"
- After coding is done the DIS/MoDiC instructs you to follow the instructions on the monitor for the installation of the Navigation System CD ROM.
- Place the navigation system software in the navigation computer CD drive. IMPORTANT: Do not switch the ignition off during the software loading procedure. Do not use any software for the Mk-3 earlier than CD V15.0.
- Once loading has been completed, remove the CD and then confirm completion by pressing the rotary push-button on the monitor.
- Turn off the key for 10 seconds, then turn it back on and conduct a functional check.
- After this step has been finished, encode the navigation computer using the "Recoding" path in ZCS Coding. The coding process involves coding vehicle specific data: VIN, Model, Telematics data etc.
The software status can be confirmed from the "Set" screen for Mk-3 systems.
Scheme 19
- 3 = Third generation system Mk-3.
- 1 = Device variant (1=Color screen, 2= MIR monochrome screen).
- 20 = Software version of the graphic component (Version 2.0). (Scheme 21): Identifying Display
After the navigation computer has been successfully programmed and coded the vehicle should be left in an area with a clear view of the sky with the key in KL R for at least 15 minutes to complete the calibration process.
Service Mode
Just as Mk-2, Mk-3 provides an on-screen service mode for diagnosis. The service mode provides five different test screens
- On-board monitor
- Navigation/Graphic element
- GPS
- Sensor Check
- Telematics
To enter the Navigation Service Mode
Scheme 20
Scheme 21
- Turn the ignition key to position 1 (KL R).
- From the Menu screen select "SET".
- Once in the Set screen, press and hold the "MENU" button for 8 seconds.
- The Service Mode menu will appear on the display.
- Select from the Service Mode menu for navigation specific tests. see scheme 20: Identifying Navigation System Display see scheme 21: Identifying Service Mode Main Menu Display
Review Questions
- List the most signoficant changes made to the Mk-3 navigation computer over the previous Mk-2._____________________________ _____________________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________________
- How can the signal provided by the gyro sensor to the navigation computer be checked?______________________________ _____________________________________________________________________________________________________________________________
- Describe how the display signals are transmitted from the navigation computer to the MIR and board monitor.______________________________ _____________________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________________
- What step is necessary before loading the navigation computer operating software CD on a newly replaced navigation computer? Where can the software status be confirmed after it has been loaded?___________________________ _____________________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________________ _____________________________________________________________________________________________________________________________
- How is the VIN entered into the navigation computer?____________________ _____________________________________________________________________________________________________________________________