1997 MERCEDES-BENZ ML320 towing

Fig. 48: Identifying Global Positioning System Location Finding
General information
The global positioning system (GPS) is a location finding system established by the US Defense Department
and is satellite supported. It is toll-free and is available throughout the world. A lot of satellites are located on
different orbits. The GPS satellites constantly transmit time and position data. If data from at least 3 satellites is
received it is possible to calculate the position of the receiver.
GPS position finding is irreplaceable for journeys outside the digitized map area and after vehicle transport (e.g.
train or ferry journeys and towing). A new GPS location finding (after interruption of satellite reception) can
last several minutes (up to 20 minutes when first commissioning the equipment).
Function
The navigation processor that is integrated in the radio (A2) calculates the location of the vehicle and the
accuracy of positioning from the satellite signals received and amplified.
The following components can receive satellite data:
Telephone and GPS roof antenna (A2/49) (model 163)
GPS antenna (A2/49a2) (model 168, 208.3, 210)
GPS rear antenna (A2/23a2) (model 170, 208.4)
GPS antenna (A2/23) (model 203, 209)
The actual calculation is essentially based on the measurement of the travel times of the signals sent
synchronously by the various satellites. Here, an important prerequisite is that the satellite and receiver clocks
are synchronized .
For this purpose, the receiver has an automatic time correction feature which again is possible with the aid of
the satellite signals.
If the navigation processor determines that the basic location finding is less accurate than the GPS location
findin
g, the position currently calculated is corrected using GPS data.

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 83 © 2006 Mitchell Repair Information Company, LLC.

and is available worldwide . Presently there are 266 satellites on 6 different earth orbits. The GPSsatellites
permanently transmit time and position data. If data from a minimum of 3 satellites is received (with two-
dimensional location finding) it is possible to calculate the position of the receiver.
The GPS location finding is particularly important when driving outside of the digitized map area and
following vehicle transport (e.g. train, ferry or towing).
A repeated GPS location finding (following satellite reception interruption) can take several minutes (when
unit is initially started up to 20 min .).
GPS map matching function
The navigation processor calculates the location of the vehicle and the accuracy of positioning from the
satellite signals received and amplified by the GPS antenna (A2/49) . The current calculation is based
primarily on the measurement of the transmission times for the signals transmitted synchronously by the
various satellites. Here, an important prerequisite is that the satellite and receiver clocks are synchronized . For
this purpose, the receiver has an automatic time correction feature which again is possible with the aid of the
satellite signals. If the navigation processor determines that the basic location finding is less precise than the
GPS location finding, the currently calculated position is corrected with the aid of the GPS data .
Moreover, the vehicle route is determined from the location sequence calculated with GPS .
Approx. 50 new GPS location finding calculations are performed each minute.
Possible interference when receiving GPS signals
Since GPS operates in the GHz (microwave) range and the signals are weak, reception interferences can
occur from
atmospheric interferences, e.g. weather, water vapor, fog,
multiple path reception due to signal reflections, e.g. from building walls
Signal shadows, e.g. in built-up areas, tunnels, high buildings, trees
A free view of the sky is therefore necessary for GPS reception The location finding accuracy is approx. 100
m or better .
Basic location finding,
function GF82.61-P-3006GI
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
GPS roof antenna/telephone, GF82.70-P-4111A

2001 Mercedes-Benz ML320
1998-2005 ACCESSORIES & BODY, CAB Electrical System - Body - 163 Chassis
me
Saturday, October 02, 2010 3:30:05 PMPage 85 © 2006 Mitchell Repair Information Company, LLC.

GENERAL NOTES: PASSENGER CARS - AH00.01-Z-0998AZ
MODEL all
Notes on TowingMODEL 461, 463AH00.60-P-0100-
02GA
Overall vehicle
Overall vehicleFG00AH00.00-Z-9999AZ
Engine
Complete engine,
crankcase ventilation,
cylinder head, crankcaseFG01AH01.00-Z-9999AZ
Crank assemblyFG03AH03.00-Z-9999AZ
Engine timingFG05AH05.00-Z-9999AZ
Mixture formationFG07AH07.00-Z-9999AZ
Air intake, superchargingFG09AH09.00-Z-9999AZ
Electrical system - engineFG15AH15.00-Z-9999AZ
Engine lubrication,
engine oil coolingFG18AH18.00-Z-9999AZ
Engine cooling systemFG20AH20.00-Z-9999AZ
Engine suspensionFG22AH22.00-Z-9999AZ
Throttle control, cruise
control systemFG30AH30.00-Z-9999AZ
Fuel systemFG47AH47.00-Z-9999AZ
Exhaust systemFG49AH49.00-Z-9999AZ
Chassis
Manual transmissionFG26AH26.00-Z-9999AZ
Automatic transmissionFG27AH27.00-Z-9999AZ
Frame, trailer operationFG31AH31.00-Z-9999AZ
SuspensionFG32AH32.00-Z-9999AZ
Rear axleFG35AH35.00-Z-9999AZ
Wheels, chassis
alignment checkFG40AH40.00-Z-9999AZ
Brakes - hydraulic and
mechanical systemsFG42AH42.00-Z-9999AZ
Brakes - pneumatic
system and auxiliary
brakesFG43AH43.00-Z-9999AZ
SteeringFG46AH46.00-Z-9999AZ
Electrical system,
equipment and
instrumentsFG54AH54.00-Z-9999AZ

2004 Mercedes-Benz ML350
1998-2005 GENINFO Overall vehicle - 163 Chassis
me
Saturday, October 02, 2010 3:47:44 PMPage 10 © 2006 Mitchell Repair Information Company, LLC.

The figure may differ from this, however, depending on quality factors.
The start distance is automatically reset to its initial value by the oil change reset each time the oil is changed.
The start distance is an internal computed quantity and cannot be displayed in the instrument cluster. It is
possible to display the start distance with the HHT.
What is normally displayed in the instrument cluster is the remaining distance .
The remaining distance is the same as the start distance immediately after the oil change. On engines with oil
sensor (e.g. 112, 113, 166, 611, 668) this applies only, however, if the specified quantity of oil has been added
during the oil change.
The remaining distance is the distance which remains from the current kilometer reading until the next
service. The possible length of the interval is at least as great as the remaining distance displayed
immediately after an oil change, and is at the most twice the start distance.
The remaining distance is dependent on
the start distance
the driving conditions (a weighting of the distance driven takes place)
any oil replenishments in the case of engines with oil sensor (e.g. 112, 113, 166, 611, 668)
Consequently, ASSYST also takes into account the driving conditions: In the case of a favorable weighting
(e.g. small number of cold starts, no high engine revs, small number of short-distance trips, minimum extent of
towing a trailer etc.) and oil replenishments, the driver is provided with a bonus which extends the remaining
distance and thus the service interval. Account is also taken of whether the vehicle is actually driven or whether
the engine runs at idle speed. ASSYST is constantly supplied with the data regarding the current operating
conditions of the vehicle for this purpose.
In the case of the best weighting , only 0.6 km are added for each kilometer driven.
In the case of the most unfavorable weighting of the distance (e.g. frequent short-distance trips, large number
of cold starts), the remaining distance and thus the service interval is smaller than in the case of the most
favorable weighting (assuming identical quality factors).
In the case of the most unfavorable weighting, up to 3 km are added for each kilometer driven.
The start distance and the remaining distance are once again presented in the form of a graph in the diagram
opposite, taking the example of gasoline engines
Each time the oil is changed, the start and remaining distances are set to the initial value. In this case, the
normal value of 15 000 km is entered as the start distance (top bar) (shaded + dark section). The start distance
may differ from 15 000 km (e.g. 14 000 km; shaded section) if the quality factors do not correspond to the basic
setting. In the case of engines fitted with oil sensor (e.g. 112, 113, 166) the start distance may also be less than
15 000 km if the specified oil quantity was not added during the oil change. The remaining distance (bottom
bar) is always 15 000 km, however, immediately after an oil change. In addition, the service interval is
always at least 15 000 km .

2004 Mercedes-Benz ML350
1998-2005 GENINFO Overall vehicle - 163 Chassis
me
Saturday, October 02, 2010 3:47:47 PMPage 204 © 2006 Mitchell Repair Information Company, LLC.