MERCEDES-BENZ ML430 1997 Complete Repair Manual

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.

See KICKDOWN SWITCH, LOCATION/TASK/DESIGN/FUNCTION MODEL 163 WITHOUT
TOUCH SHIFT.
Starter Lock-Out Contact, Location/Task/Design/Function

See STARTER LOCK
-OUT CONTACT, LOCATION/TASK/DESIGN/FUNCTION.
Temperature Sensor, Location/Task/Design/Function

See TEMPERATURE SENSOR, LOCATION/TASK/DESIGN/FUNCTION
.
Wheel Speed Sensor, Location/Task/Function

See WHEEL SPEED SENSOR, LOCATION/TASK/FUNCTION
.
Location/Task/Design/Function Of Oil Pump

See LOCATION/TASK/DESIGN/FUNCTION OF OIL PUMP
.
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 286 © 2006 Mitchell Repair Information Company, LLC.

Fig. 161: Kickdown Switch
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
Kickdown Switch Position

The kickdown switch (S16/6) is located in the footwell behind the accelerator pedal. See Fig. 161
.
Kickdown Switch Task

Influencing the shift program of the electronic transmission control.
Kickdown Switch Design

The kickdown switch (S16/6) consists of a spring-tensioned electrical switch contact.
Kickdown Switch Function


2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
me
Saturday, October 02, 2010 3:15:30 PMPage 287 © 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
me
Saturday, October 02, 2010 3:15:30 PMPage 288 © 2006 Mitchell Repair Information Company, LLC.

Fig. 162: Function Of Locking Of Selector Lever Position "P"
Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
One of the functions of the shift lock is to lock the selector lever in position "P". The selector lever is locked
electronically. See Fig. 162
.
The selector lever remains disabled in position "P", if the brake is not operated or there is no power supply to
the electronic selector lever module control module (N15/5) (circuit 87).
The electronic selector lever module control module (N15/5) actuates the R/P lock solenoid valve (89) from the

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
me
Saturday, October 02, 2010 3:15:30 PMPage 289 © 2006 Mitchell Repair Information Company, LLC.

ignition key position Ignition "ON" when the brake pedal is depressed and therefore when the brake lamp
switch (S9/1) is actuated and when selector lever position "P" is recognized.
The R/P locking magnet (89) releases the selector lever thus allowing the selector lever to be moved away from
position "P".
Parking Lock, Location/Task/Design/Function - See PARK PAWL,
LOCATION/TASK/DESIGN/FUNCTION.
Ignition Lock Interlock
Operation

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMISSIONS Complete Transmissions - ML 320 - 722.662
me
Saturday, October 02, 2010 3:15:30 PMPage 290 © 2006 Mitchell Repair Information Company, LLC.

Fig. 163: Ignition Lock Interlock

2001 Mercedes-Benz ML320
1998-03 AUTOMATIC TRANSMI SSIONS Complete Transmissions - ML 320 - 722.662
me
Saturday, October 02, 2010 3:15:30 PMPage 291 © 2006 Mitchell Repair Information Company, LLC.