1997 MERCEDES-BENZ ML320 navigation system

4-channel power amplifier for vehicle loudspeakers
System interlinkage
The radio and navigation unit (A2/56) is provided with the following components for data exchange with
external digital components:
CAN (A1 -A2/56)
The radio and navigation unit (A2/56) is connected with the instrument cluster (A1) via a separate
CAN bus. The difference to the other CAN systems is indicated by the spelling CAN bus (A1-A2/56).
The CAN bus (A1-A2/56) allows the following functions:
Operation of the radio and navigation unit (A2/56)is also possible with the multifunction steering
wheel.
The multifunction display (A1/p13) in the instrument cluster (A1) can display navigation
information on the current operating status of the radio and navigation unit (A2/56) .
The connection to the CAN bus (A1-A2/56) is only realized on models 208 and 210. (Status 3/99)
Digital data bus (D2B)
Data can be exchanged between the external audio components, the telephone system and - if present -
the voice control system over the D2B bus. This allows control data as well as the actual audio signals
(e.g. music from CD changer) to be transferred.
The only additional D2B component presently possible is the CD changer (A2/6) (Status: 3/99)
K bus (diagnostic interface)
Data exchange is accomplished between the diagnostic interface and the hand-held tester (reading out
DTCs and actual values, ...).
The communication between the HHT and all other D2B components is accomplished over the radio
and navigation unit (A2/56) diagnostic interface.
Audio 30 APS, location of
componentsModel 163GF82.61-P-0002-01D
Model 168GF82.61-P-0002-01B
Model 170GF82.61-P-0002-01A
Model 208, model 210&.2.(GF82.61-P-0002-
01C)
Audio 30 APS block
diagramModel 163GF82.61-P-0002-02D
Model 168GF82.61-P-0002-02B

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 74 © 2006 Mitchell Repair Information Company, LLC.

TABLE OF CONTENTS, FUNCTION DESCRIPTION OF AUDIO 30 APS - GF82.61-P-0998ZZ
MODEL 163, 168, 170, 203.0 /2 /7, 208, 209.3 /4, 210 with CODE (353) Audio 30 APS
Model 170GF82.61-P-0002-02A
Models 208, 210&.2. (GF82.61-P-0002-
02C)
Audio 30 APS operating
instructions GF82.61-P-0002-03A
On/Off behavior, function GF82.85-P-2006B
Navigation mode, function GF82.85-P-2012B
Radio mode, function GF82.60-P-2001B
CD player mode, function GF82.60-P-2002B
Volume and tone settings,
function GF82.60-P-2003B
Digital data bus (D2B),
function GF82.00-P-0001A
Radio and navigation unit,
location/purpose/
design/function GF82.61-P-4109A
Audio 30 APS, functionModels 163, 168,
170, 208, 210GF82.61-P-0002A
Model 203, 209.3/4GF82.61-P-0002E
Audio 30 APS location of the
componentsModel Series 163GF82.61-P-0002-
01D
Model 168GF82.61-P-0002-
01B
Model 170GF82.61-P-0002-
01A
Models 203, 209.3GF82.61-P-0002-
01E
Model 209.4GF82.61-P-0002-
01F
Models 208, 210GF82.61-P-0002-
01C
Audio 30 APS block diagramModel Series 163GF82.61-P-0002-
02D
Model 168GF82.61-P-0002-
02B
Model 170GF82.61-P-0002-
02A
Models 203, 209GF82.61-P-0002-
02E

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 75 © 2006 Mitchell Repair Information Company, LLC.

CONSTANT MAP MATCHING, FUNCTION - GF82.61-P-2002GI
MODEL 163 as of 1.9.01 with CODE (522) Modular control system (MCS) radio USA with CODE (357)
Navigation system - additional unit with CODE (818b) Single CD player - additional unit with CODE
(491) U.S. version
Models 208, 210GF82.61-P-0002-
02C
Audio 30 APS operating instructionsModels 163, 168,
170, 208, 210GF82.61-P-0002-
03A
Model 203, 209GF82.61-P-0002-
03E
Switch on/off behavior, function GF82.85-P-2006B
Navigation mode, functionModels 163, 168,
170, 208, 210GF82.85-P-2012B
Model 203, 209GF82.85-P-2012EE
Radio operation, function GF82.60-P-2001B
CD-player mode, function GF82.60-P-2002B
Telephone mode, functionModel 209GF82.85-P-2007QA
Volume/tone adjustments, function GF82.60-P-2003B
Loading language, function GF82.61-P-3003B
Basic location finding, function GF82.61-P-3006D
Global positioning system location
finding, function GF82.61-P-3007C
Map-supported location finding,
function GF82.61-P-3008C
Route calculation, function GF82.61-P-3011E
Destination guidance, function GF82.61-P-3012D
Destination guidance in digitalized map
area, function GF82.61-P-4000C
Destination guidance in non-digitalized
map area, function GF82.61-P-4001C
Dynamic route guidance, function GF82.61-P-4003QA
Survey of system components, Audio
30 APS, location/task/design/function GF82.61-P-9998ZZ

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 76 © 2006 Mitchell Repair Information Company, LLC.

by the navigation processor Integrated Into the radio and navigation module (A2/56) .
During the switch-on phase (software is loaded), only basic map matching is available.
When the ignition is switched off all important location finding parameters are stored for the duration of the
shut-off delay (approx. 60 min) .
The permanent location finding feature uses three procedures which supplement each other ensuring very
precise and reliable location finding:
Basic location finding (dead reckoning)
Map-supported location finding (map matching)
GPS location finding
Manual entry of vehicle location
It is possible to enter the location manually on the operating and display module. This can be useful in the
following cases:
Following vehicle transport
(e.g. ferry or train) or
when GPS reception is not present when trip is started
LOADING LANGUAGE, FUNCTION - GF82.61-P-3003B
MODEL 163, 168, 170, 203.0 /2 /7, 208, 209.3 /4, 210 with CODE (353) Audio 30 APS
Function
The data for navigation voice output is stored originally on the navigation DVD. They are transmitted with the
help of the DVD drive of the radio (A2) into the memory of the navigation processor and are then available
anytime for navigation.
The language is reloaded in the following cases:
Basic location finding,
function GF82.61-P-3006GI
Global positioning system
location finding, function GF82.61-P-3007GI
Map-supported location
finding, function GF82.61-P-3008GI
Radio and navigation
module, location/purpose/
design/function GF82.61-P-4109GI

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 78 © 2006 Mitchell Repair Information Company, LLC.

automatically, after voltage to the radio (A2) was interrupted
manually, by activating the "SPRA" menu in the navigation mode
Loading the language requires approx. 20 s.
If the system is switched off while loading the language, the language data is lost and must be reloaded again.
Avoid strong vibrations to the vehicle (e.g. extremely bumpy roads) while the language is being loaded.
The navigation processor is integrated in the radio (A2).
BASIC LOCATION FINDING, FUNCTION - GF82.61-P-3006D
MODELS 163, 168, 170, 203.0 /2 /7, 208, 209.3 /4, 210 with CODE (353) Audio 30 APS
Basic representation of the basic location finding shown on model 210
Basic location finding (dead reckoning) is the basic function of continuous location finding. It is permanently
carried out by the navigation processor that is integrated in the radio (A2) when the ignition is switched on
(approx. once per second) and is irrespective of the data of the DVD map. After switching off the ignition, the
current position is stored for the duration of the system shut-off delay time.
Fig. 46: Identifying Basic Location Finding Function

The following information is calculated with the aid of basic location finding:
Distance traveled
Absolute vehicle direction (compass direction)
Direction of travel (forward or reverse)
Calculation of distance traveled
The navi
gation processor receives the wheel speed signal of the following components:
Route calculation,
function GF82.61-P-3011E

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 79 © 2006 Mitchell Repair Information Company, LLC.

Left rear rpm sensor (L6/3) (model 168)
Wheel speed sensor, left front (L6/1)
Right front rpm sensor (L6/2) (model 208, 210)
Left front rpm sensor (L6/1) and right front rpm sensor (L6/2) (models 203, 209)
The evaluation of the wheel speed signals reveals the mileage covered.
The wheel speed signals of the not driven wheels are evaluated, since their slip between the roadway and tire
is lower, which results in a more accurate result when calculating the mileage.
Calculation of the vehicle orientation
The navigation computer calculates the direction in which the vehicle is traveling (compass direction) from the
data from the gyrosensor and the sequence of locations calculated with the aid of the global positioning system
(GPS). The difference in the calculated mileage and the mileage actually covered between 2 turn-off points is
used to automatically recalibrate the tire circumference (necessary due to tire wear).
Calculation of the direction of motion
The navigation processor recognizes the direction of motion (forward or reverse) from the reverse signal.
Calibration of tire circumference
As a matter of principle, the navigation system recalibrates itself while driving as described. However, this may
require driving a longer distance. After changing tires, manual recalibration should therefore be accomplished.
To do this, it is necessary to enter the tire size (e.g.:195/050/015)and possibly the following information:
new tires (tread depth > approx. 5 mm)
used tires (tread depth < approx. 5 mm)
The entry can be done two different ways:
With aid of STAR DIAGNOSIS.
By calling the "Navigation --> TIRE" menu at the radio (A2)
Errors due to vehicle movement with switched off ignition lead to an inaccurate basic location finding.
Rolling backwards without the reverse gear engaged is evaluated as forwards motion, and may lead to an error
in the location finding. Rolling with the ignition switched off or vehicle transportation also falsify map
matching.
The errors are, however, corrected automatically after a short time by the navigation processor after
receiving GPS data.
A special calibration drive by driving around a defined test path is not ever required.

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 80 © 2006 Mitchell Repair Information Company, LLC.

BASIC LOCATION FINDING, FUNCTION - GF82.61-P-3006GI
MODEL 163 as of 1.9.01 with CODE (522) Modular control system (MCS) radio USA with CODE (357)
Navigation system - additional unit with CODE (818b) Single CD player - additional unit with CODE
(491) U.S. version
Fig. 47: Identifying Basic Location Finding, Function

Basic location finding (dead reckoning)
Is the basic function of permanent location finding It is accomplished permanently by the navigation processor
when the ignition is switched on and is not dependent on the CD-ROM map.
The current position is stored after the ignition is switched off.
The following information is calculated with the aid of basic location finding :
Distance traveled
Direction of motion (forward or backward) and
Direction in which vehicle is pointing
Basic location finding is accomplished approx. once per second .
Distance traveled
The navigation processor receives the signals output by the front right wheel speed sensor (L6/2) from the
traction system control module (N47) via discrete leads.
Evaluation of the wheel speed signals allows calculation of the distance traveled.
Direction of motion
Map-supported location
finding, function GF82.61-P-3008C

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 81 © 2006 Mitchell Repair Information Company, LLC.

The navigation processor recognizes the direction of motion (forward or reverse) from the reverse signal.
Direction in which vehicle is pointing
From the data of the gyrosensor and the sequence of the locations calculated with GPS the navigation
processor the calculates the direction in which the vehicle is pointing (compass direction).
The difference between calculated and actual distance traveled between two turning points is used for automatic
recalibration of the tire circumference (required due to tire wear).
Location finding errors during basic location finding
Rolling backwards without the reverse gear engaged is evaluated as forward motion, and may lead to an error in
the location finding.
Rolling with the ignition switched off or vehicle transportation also falsify map matching.
In both cases the deviation is automatically corrected by the navigation processor after receiving GPS data .
Calibration
Wheel calibration is not required following tire change.
GLOBAL POSITIONING SYSTEM LOCATION FINDING, FUNCTION - GF82.61-P-3007C
MODEL 163, 168, 170, 203.0 /2 /7, 208, 209.3 /4, 210 with CODE (353) Audio 30 APS
Basic representation of the GPS location finding shown on model 210
Global positioning system
location finding, function GF82.61-P-3007GI
Map-supported location
finding, function GF82.61-P-3008GI
Guidance, function GF82.61-P-3012GI
Radio and navigation
module, location/purpose/
design/function GF82.61-P-4109GI

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 82 © 2006 Mitchell Repair Information Company, LLC.