1997 MERCEDES-BENZ ML320 automatic transmission

Selector Lever Position/Shift Range
ETC Control Unit, Task
Transmission 722.6 in 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 278 © 2006 Mitchell Repair Information Company, LLC.

Fig. 158: ETC Control Module without Touch Shift
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Task

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMI SSIONS Complete Transmissions - ML 320 - 722.662
me
Saturday, October 02, 2010 3:15:29 PMPage 279 © 2006 Mitchell Repair Information Company, LLC.

The ETC control module (N15/3) determines the instantaneous operating condition of the vehicle and controls
all gearshift sequences taking into account the ease of shifting and the driving situation. See Fig. 158
. This
involves receiving , converting and transmitting various digital and analog signals.
Input Signals:
Starter Lock-Out Contact (Y3/6S1)
RPM Sensor 2 (Y3/6N2)
RPM Sensor 3 (Y3/6N3)
Transmission Oil Temperature Sensor (Y3/6B1)
Kickdown Switch (S16/6)
Gear Recognition Switch (S16/10)
Output signals:
Reverse/Parking Lock Valve
Input And Output Signals:
Datalink Connector (X11/4)
In addition there is a connection via the engine compartment bus to the:
ME-SFI Control Module (N3/10) or CDI Control Module (N3/9)
Traction System Control Module (N47)
Transfer Case Control Module (N78)
The solenoid valves for the modulating and shift pressure and for the gear changes are actuated by the ETC
control module (N15/3). The pressure required is calculated from all input signals, adjusted to the torque to be
transferred.
The following information from other systems is then processed:
ME-SFI Control Module (N3/10) or CDI Control Module (N3/9)
Reverse And Parking Lock Solenoids (Y66/1)
Selector Lever Position (P/N) to the Engine Control Module (ME-SFI) (N3/10) (only on detection of the
selector lever position "P" or "N" on the transmission range recognition switch (S16/10) and at the starter
interlock contact (Y3/6s1)).
Traction System Control Module (N47):
Wheel Speeds
Gear Shift
Traction Status

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
me
Saturday, October 02, 2010 3:15:29 PMPage 280 © 2006 Mitchell Repair Information Company, LLC.

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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Saturday, October 02, 2010 3:15:29 PMPage 281 © 2006 Mitchell Repair Information Company, LLC.

Fig. 159: Function Of Torque Converter Lockup Clutch Control
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
me
Saturday, October 02, 2010 3:15:29 PMPage 282 © 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. 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
me
Saturday, October 02, 2010 3:15:29 PMPage 283 © 2006 Mitchell Repair Information Company, LLC.

See TORQUE CONVERTER LOCKUP CL UTCH REGULATING VALVE,
LOCATION/TASK/FUNCTION.
Kick-Down Function (Up To 5/31/02) (With Touch Shift)
Transmission With Touch Shift 722.6 In Model 163
Fig. 160: Kick
-Down Function (Up To 5/31/02)

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMI SSIONS Complete Transmissions - ML 320 - 722.662
me
Saturday, October 02, 2010 3:15:29 PMPage 284 © 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
me
Saturday, October 02, 2010 3:15:29 PMPage 285 © 2006 Mitchell Repair Information Company, LLC.