1997 MERCEDES-BENZ ML320 engine

Transfer Case Control Module (N78):
Position of Transfer Case (off-road or on-road ratio)
Engine Torque
Engine Speed
Accelerator Pedal Position
Gear Soft
Engine Status
The following information is output to other systems:
ME-SFI Control Module (N3/10) or CDI Control Module (N3/9):
Kickdown Switch (S16/6)
Engage Drive Mode
Traction System Control Module (N47):
Transmission Ratio
Speeds
Oil Level Control, Function
Operation - The oil level control system seals the opening between the oil gallery and gearset chamber so that
the rotating gearsets do not splash about in oil as the oil level rises. The oil level control reduces power loss and
prevents oil from being thrown out of the transmission housing at high oil temperatures.
Float, Location/Function

See SHIFT PRESSURE REGULATING VALVE, LOCATION/TASK/FUNCTION
.
Transmission Housing Breathing, Location/Task

See TRANSMISSION HOUSING BREATHING, LOCATION/TASK
.
Function Of Torque Converter Lockup Clutch Control
Operation

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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The aim of using the torque converter lockup clutch is to reduce the fuel consumption and exhaust gas
emissions of the vehicle by reducing torque converter slip. See Fig. 159
. This stands in contradiction to the ride
comfort demands made on the drive train with regard to its vibration behavior. The task of the electronic
transmission control is therefore to close the clutch in all driving situations relevant to fuel consumption, if
possible, and ensure that the engine vibrations are isolated from the drive train.
The characteristic curves shown in the diagram illustrate the different operating states of the torque converter
lockup clutch in relation to the accelerator pedal position and transmission output speed, plotted for one
transmission gear.
In addition to the evaluation of these characteristics, the status of the torque converter lockup clutch is also
determined by other variables.
Variables influencing the states of the torque converter lockup clutch:
Accelerator Pedal Movement
Uphill And Down Hill Gradients
Transmission Shift Functions
ATF Temperature
Durability Requirements
Load Condition
Engine Control Influences
Torque Converter Lockup Clutch Control Pressure, Function

See TORQUE CONVERTER LOCKUP CLUTCH CONTROL PRESSURE, FUNCTION
.
Torque Converter Lockup Clutch Control Pressure, Function
Apart from extreme states of open or closed, it is possible to operate the torque converter lockup clutch with
preset slip speeds. To enable this variable control pressure must be applied to the torque converter lockup clutch
regulating valve.
The torque converter lockup clutch control pressure is adapted to each operating state via the pulse-width
modulated torque converter lockup solenoid valve (Y3/6y6) which is actuated by the ETC control unit (N15/3).
Torque Converter Lockup Clutch PWM Solenoid Valve, Location/Task/Design/Function

See LOCATION/TASK/DESIGN/FUNCTION OF PWM SOLENOID VALVE, TORQUE
CONVERTER LOCKUP CLUTCH.
Torque Converter Lockup Clutch, Location/Task/Design/Function

See TORQUE CONVERTER LOCK
-UP CLUTCH, LOCATION/TASK/DESIGN/FUNCTION.
Torque Converter Lockup Clutch Regulating Valve, Location/Task/Function

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Saturday, October 02, 2010 3:15:29 PMPage 283 © 2006 Mitchell Repair Information Company, LLC.

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Operation
The driver's wish for maximum acceleration of the vehicle is met with the kick-down function. See Fig. 160.
When the kick-down switch (S16/6) is operated a CAN Signal is passed on from the electronic selector lever
module control module (N15/5) to the ETC control module (N15/3) via the electronic accelerator.
Based on this information the ETC control module (N15/3) actuates the solenoid valves so that the upshifts and
downshifts take place at higher engine speeds in order to achieve maximum performance.
Kick-Down Switch, Location/Task/Design

See KICK
-DOWN SWITCH, LOCATION/TASK/DESIGN.
Hydropneumatic Transmission Control, Function (Without Touch Shift)
Operation
The hydropneumatic transmission control is divided into electronic and hydraulic transmission control.
While the electronic transmission control is responsible for gear selection and for matching the pressures to the
torque to be transmitted, the transmission's power supply control occurs via hydraulic elements in the
electrohydraulic control module. The oil supply to the hydraulic elements, such as the hydrodynamic torque
converter, the shift elements and the hydraulic transmission control, is provided by way of an oil pump
connected with the torque converter.
The electronic transmission control (ETC) allows for the precise adaptation of pressures to the corresponding
operating conditions and to the engine output during the gearshift phase, resulting in a noticeable improvement
in shift quality.
It is possible to reach the engine RPM limit in the individual gears using full throttle and kick-down. The shift
range can be changed in the forward gears while driving, but the electronic transmission control (ETC) employs
a downshift safeguard to prevent over-revving the engine.
The system offers the additional advantage of flexible adaptation to different vehicle and engine variants.
ETC Control Module, Location/Task

See ETC CONTROL UNIT, LOCATION/TASK
.
Electric Control Module, Location/Task/Design/Function

See ELECTRONIC CONTROL MODULE, LOCATION/TASK/DESIGN/FUNCTION
.
Kickdown Switch, Location/Task/Design/Function Model 163 Without Touch Shift


2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Saturday, October 02, 2010 3:15:29 PMPage 285 © 2006 Mitchell Repair Information Company, LLC.

When the kick-down switch (S16/6) is operated via the accelerator pedal a signal is passed on to the ETC
control module (N15/3). Based on this information the ETC control module (N15/3) actuates the solenoid
valves so that the upshifts and downshifts take place at higher engine speed.
Shift-Lock Function
Operation
The term shift lock combines the functions which, in addition to the parking brake, offer an additional safeguard
for the vehicle to prevent it moving off unintentionally.
These include the functions of locking the selector lever position "P" and locking the ignition lock as well as the
parking lock in the transmission.
The shift lock function only allows shifting out of selector lever position "P" if the transmitter key (A8/1) has
been turned into the position "Ignition: ON" and the brake pedal is depressed.
In order to ensure that after parking the vehicle the selector lever is shifted into selector lever position "P", the
transmitter key (A8/1) can only be turned towards "0" in this position and removed from the EZS control
module (N73) (ignition lock locking, function).
The vehicle is secured mechanically by blocking the park pawl gear.
In the event of mechanical or electrical/electronic faults it is possible to unlock selector lever position "P"
manually (shift lock override function).
Function Of Locking Of Selector Lever Position "P"

See FUNCTION OF LOCKING OF SELECTOR LEVER POSITION "P"
.
Ignition Lock Locking, Function

See IGNITION LOCK INTERLOCK
.
Function Of Shift Lock Override

See FUNCTION OF SHIFT LOCK OVERRIDE
.
Function Of Locking Of Selector Lever Position "P" (With Touch Shift)
Operation

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Saturday, October 02, 2010 3:15:30 PMPage 288 © 2006 Mitchell Repair Information Company, LLC.

The aim of using the torque converter lockup clutch is to reduce the fuel consumption and exhaust gas
emissions of the vehicle by reducing torque converter slip. See Fig. 165
. This stands in contradiction to the ride
comfort demands made on the drive train with regard to its vibration behavior. The task of the electronic
transmission control is therefore to close to the clutch in all driving situations relevant to fuel consumption, if
possible, and ensure that the engine vibrations are isolated from the drive train.
The characteristic curves shown in the diagram illustrate the different operating states of the torque converter
lockup clutch in relation to the accelerator pedal position and transmission output speed, plotted for one
transmission gear.
In addition to the evaluation of these characteristics, the status of the torque converter lockup clutch is also
determined by other variables.
Variables influencing the states of the torque converter lockup clutch:
Accelerator Pedal Movement
Uphill And Down Hill Gradients
Transmission Shift Functions
ATF Temperature
Durability Requirements
Load Condition
Engine Control Influences
Torque Converter Lockup Clutch Control Pressure, Function

See TORQUE CONVERTER LOCKUP CLUTCH CONTROL PRESSURE, FUNCTION
.
REMOVE/INSTALL TRANSFER CASE
Remove/Install

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Saturday, October 02, 2010 3:15:30 PMPage 296 © 2006 Mitchell Repair Information Company, LLC.

5 - Detach plug (3) from actuator motor.
6 - Support transmission and remove rear engine crossmember (5) with engine mount.
7 - Slightly lower engine transmission unit.
8 - Support transfer case (2) with lifting device. See SUPPORTING TRANSMISSION WITH
INSPECTION PIT LIFT.
9 - Unscrew bolts (4) and take out transfer case to the back.
10 - Install in the reverse order.
11 - Check filling capacity of transfer case.
Check transfer case (2) for leaks.
Torque Specifications; Driveshaft NOTE: Hang up propeller shaft to one side and ensure that the universal joint is
not damaged.
Self-locking bolt, propeller shaft to transfer case (to front axle). See
Torque Specifications; Driveshaft
.
NOTE:
Engine 112:
Bolt of rear engine crossmember to body.
Engine 112:
Bolt or nut, rear engine mount to transmission.
NOTE: Ensure that no lines are damaged.
NOTE: Transmission plate.
NOTE: Bolt, transfer case to automatic transmission.
Bolt, transfer case to manual transmission.
NOTE: Correct oil level: Bottom edge of filler hole.
Screw plug to transfer case.
DesignationModel 163
Self-locking bolt, front propeller shaft to transfer case (to rear axle)Nm40

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Saturday, October 02, 2010 3:15:30 PMPage 298 © 2006 Mitchell Repair Information Company, LLC.

Torque Specifications; Engine Mounts, Engine Supports
Torque Specifications; Engine Suspension, Engine Mounts, Engine Supports
Torque Specifications; Engine Suspension, Engine Mounts, Engine Supports
Torque Specifications; Transfer Case, Complete Unit
Fig. 167: Commercially Available Tools (See Workshop Equipment Manual)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Remove/Install Noise Encapsulation
Self-locking screw, propeller shaft to transfer case (to front axle)Nm50
DesignationEngine 112.942/970 113.942/965/ in model 163.154/157/
172/174/175
Bolt of rear engine crossmember to bodyNm40
Bolt or nut, rear engine mount to
transmissionM8Nm-
M10Nm40
DesignationEngine 612.963 in model
163.113Engine 628.963 in model
163
Bolt/nut, rear engine crossmember to
bodyNm4040
Bolt or nut, rear engine mount to
transmissionNm4040
DesignationEngine 111 in model 163
Bolt of rear engine crossmember to bodyNm40
Bolt or nut, rear engine mount to transmissionNm35
DesignationModel 163
Threaded plug in transfer caseNm30
Bolt, transfer case to automatic transmissionNm20
Bolt, transfer case to manual transmissionNm20

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Saturday, October 02, 2010 3:15:30 PMPage 299 © 2006 Mitchell Repair Information Company, LLC.

Basically automatic transmission 722.6 with electronic control offers the following advantages:
Reduced Fuel Consumption
Improved Shift Comfort
More Favorable Gear Steps As A Result Of 5 Gears
Enhanced Life And Reliability
Reduced Servicing Costs
The electrohydraulic control unit is bolted onto the bottom of the transmission housing. The end of the
transmission is formed by an oil pan made of sheet steel.
The oil pressure for the converter lockup clutch and center multiple-disc clutch is supplied via holes in the input
shaft. The oil pressure to the rear multiple-disc clutch is routed through the output shaft. The lubricating oil is
supplied and distributed by additional bore holes in both shafts. All bearing points of the gear sets as well as
freewheels and shift elements are supplied with lubricating oil.
The parking lock gear and drive flange are connected to the output shaft by gearing.
Freewheels F1 and F2 optimize shifting. The front freewheel (F1) rests against the stator shaft extension on the
transmission side and connects the sun gear of the front planetary gear set to the transmission housing in the
locking direction.
The torque converter housing and transmission housing are made of a metal alloy. They are bolted together and
centered via the outer multiple-disc carrier of the multiple-disc brake B1. A coated intermediate panel seals the
two components.
The oil pump and outer multiple-disc carrier of the front multiple-disc brake are bolted to the converter housing.
The mechanical part consists of the propeller shaft, output shaft, a sun gear shaft and three planetary gearsets
which are coupled together.
In transmissions for powerful engines, the planetary gearsets have 4 planetary gears, while for less powerful
engines the front and rear planetary gear system has three planetary gear wheels. The stator shaft is pressed into
this and is secured against turning by a spline.
The rear freewheel F2 connects the sun gear of the center planetary gear set to the sun gear of the rear planetary
gearset in the locking direction.
The electrohydraulic control unit consists of the shift plate made of light alloy for hydraulic control and an
electronic control unit.
The electrical control unit consists of a supporting body made of plastic in which the electrical components are
combined. The shell is screwed to the shift plate. Conductor tracks which are integrated into the shell, connect
the electric components to a plug connector. This 13-pin plug connector forms the connection with the vehicle-
side wiring harness and with the ETC 5 (electronic transmission control) control module (N15/5) via a bayonet
lock.

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
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Saturday, October 02, 2010 3:15:30 PMPage 302 © 2006 Mitchell Repair Information Company, LLC.