2005 MERCEDES-BENZ SPRINTER Service Repair Manual

(8) Inspect axial play (Fig. 203) between shim (10)
and retaining ring (11). Check axial play9S9between
shim (10) and retaining ring (1) using a feeler gauge.
Clearance should be 0.15-0.6 mm (0.006-0.024 in.).
Shims are available in thicknesses of 3.0 mm (0.118
in.), 3.4 mm (0.134 in.), and 3.7 mm (0.146 in.).
Adjust as necessary
NOTE: During the test, apply a contact force by
hand to K3 in the direction of the arrow.
SHIFT MECHANISM
DESCRIPTION
The automatic transmission is operated with the
help of a shift lever assembly (SLA) located in the
center console. There are four positions to which the
selection lever can be shifted: P, R, N, D. In addition,
the selector lever can be moved sideways (+/-) in posi-
tion9D9to adjust the shift range.
All selector lever positions, as well as selected shift
ranges in position9D9, are identified by the SLA. The
information is then sent to the transmission control
module (TCM) via a hardwire connection. At the
same time, the selector lever positions9P9,9R9,9N9
and9D9are transmitted by a shift cable to the selec-
tor shaft in the transmission.
The SLA is comprised of the following functions:²Key lock:Depending on the selector lever posi-
tion, the ignition lock is locked/unlocked, i.e., the
ignition key can be removed only if the selector lever
is in position9P9. A park lock cable is used to perform
this function.
²Park lock:The selector lever is not released
from postion9P9until the brake pedal has been
applied and the ignition key is in driving position.
Shift lock is controlled by the brake light switch in
conjunction with a locking solenoid in the SLA. As
soon as the brake pedal is applied firmly, the locking
solenoid is retracted to unlock the selector lever. If
the selector lever cannot be moved out of position9P9
due to a malfunction, the shift lock function can be
overriden (see operator's manual).
²Reverse inhibitor:As soon as the vehicle
speed exceeds approx. 4 mph, it is no longer possible
to move the selector lever from position9N9to posi-
tion9R9.
OPERATION
With the selector lever in position9D9, the trans-
mission control module (TCM) automatically shifts
the gears that are best-suited to the current operat-
ing situation. This means that shifting of gears is
continuously adjusted to current driving and operat-
ing conditions in line with the selected shift range
and the accelerator pedal position. Starting off is
always performed in 1st gear.
The selector lever positions are determined by the
slider position of a potentiometer in the shift lever
assembly (SLA). The shift pattern diagram (position
display) and the program selector are illuminated by
the LEDs.
The current selector lever position or, if the shift
range has been limited, the current shift range is
indicated in the LCD display in the instrument clus-
ter.
The permissible shifter positions and transmission
operating ranges are:
²P = Parking lock and engine starting.
²R = Reverse.
²N = Neutral and engine starting (no power is
transmitted to the axles).
²D = The shift range includes all forward gears.
²4= Shift range is limited to gears 1 to 4.
²3= Shift range is limited to gears 1 to 3.
²2= Shift range is limited to gears 1 to 2.
²1= Shift range is limited to the 1st gear.
The shift range can be adjusted to the current
operating conditions by tipping the selector lever to
the left-hand side (9-9) or the right-hand side (9+9)
when in position9D9. If the shift range is limited, the
display in the instrument cluster indicates the
selected shift range and not the currently engaged
gear.
Fig. 203 Check Center and Rear Planetary End-Play
1 - DRIVING CLUTCH K3
2 - THRUST WASHER
3 - SHIM
4 - AXIAL NEEDLE BEARING
5 - RETAINING RING
6 - OUTPUT SHAFT WITH CENTER PLANETARY CARRIER
VAAUTOMATIC TRANSMISSION - NAG1 21 - 133
PLANETARY GEARTRAIN (Continued)

Tipping the shift lever will have the following
results:
²Tipping the selector lever toward(-(one
time after another:The shift range is reduced in
descending sequence by one gear each time, i.e., from
D-4-3-2-1.Iftheselected limitation of the shift
range would result in a downshift causing excessive
engine speed, the shifting is not executed and the
engaged gear as well as the shift range remain
unchanged. This is to prevent the engine from over-
speeding. Engine retardation is low with the selector
lever in position9D9. To make use of the full braking
power of the engine,9manual9downshifting by tip-
ping the lever towards the left-hand side is recom-
mended. If this has been done, subsequent upshifting
must be carried out manually as well.
²Tipping the selector lever toward(-(and
holding it in this position:The currently engaged
gear in range9D9is indicated in the instrument clus-
ter display and the shift range is limited to this gear.
²Tipping the selector lever toward(+(one
time after another:The shift range is increased by
one gear each time and the increased shift range is
displayed in the instrument cluster; possibly, the
transmission upshifts to a faster gear.
²Tipping the selector lever toward(+(sev-
eral times:The shift range is increased by one gear
each time the lever is tipped until the shift range
ends up in9D9.
²Tipping the selector lever toward(+(and
holding it in this position:The shift range is
extended immediately to9D9, shift ranges are indi-
cated in ascending sequence; possibly, the transmis-
sion upshifts to a faster gear due to the extension of
the shift range.
REMOVAL
(1) Move selector lever to position9D9.
(2) Remove top section (3) (Fig. 204) of the center
section of instrument panel.
(3) Remove bottom section (2) (Fig. 205) of the cen-
ter section of instrument panel.
(4) Disconnect the park lock cable coupling (1)
(Fig. 206) from the shift lever assembly (SLA). Press
locking tab (2) together and push coupling (1) against
the spring force into the SLA, twist through 90É
(right or left) and pull off.
(5) Disconnect connector plug (5) from SLA. When
disconnecting plug, press together at points shown
(arrows).
(6) Pry ball socket (4) of transmission shift cable
off ball knob at the SLA. Use a suitable slotted
screwdriver.
Fig. 204 Remove Top Section Of Center Instrument
Panel
1 - SHIFT LEVER ASSEMBLY FRAME TRIM
2 - STORAGE COMPARTMENT
3 - TOP CENTER PART OF INSTRUMENT PANEL
4 - SCREW
5 - PLUG CONNECTIONS
6 - ASHTRAY
Fig. 205 Remove Bottom Section Of Center
Instrument Panel
1 - SCREW
2 - BOTTOM CENTER PART OF INSTRUMENT PANEL
21 - 134 AUTOMATIC TRANSMISSION - NAG1VA
SHIFT MECHANISM (Continued)

(7) Unscrew bolts (1) (Fig. 207).
(8) Move selector lever to position9P9.
(9) Remove the SLA (2) from the vehicle.
INSTALLATION
(1) Position the shift lever assembly (SLA) onto
the vehicle.
(2) Install the bolts to hold the SLA to the vehicle.
Tighten the bolts to 6 N´m (53 in.lbs.).
(3) Connect the park lock cable coupling (1) (Fig.
208) to the SLA. Press locking tab (2) together and
push coupling (1) against the spring force into the
SLA, twist through 90É (right or left) until locked.
(4) Connect the connector plug (5) to the SLA.
(5) Turn on ignition and apply brakes. Move selec-
tor lever back to position9D9.
(6) Install the transmission shift cable onto the
ball knob at the SLA.
(7) Install the bottom (2) (Fig. 209) of the center
section of instrument panel.
(8) Install the top (3) (Fig. 210) of the center sec-
tion of instrument panel.
(9) Verify repair.
Fig. 206 Disengage Park Lock Cable From SLA
1 - PARK LOCK CABLE COUPLING
2 - LOCK TAB
3 - BOLT
4 - SHIFT LEVER ASSEMBLY (SLA)
5 - CONNECTOR
Fig. 207 Remove SLA
1 - BOLT
2 - SLA
3 - SHIFT CABLE
Fig. 208 Engage Park Lock Cable to SLA
1 - PARK LOCK CABLE COUPLING
2 - LOCK TAB
3 - BOLT
4 - SHIFT LEVER ASSEMBLY (SLA)
5 - CONNECTOR
VAAUTOMATIC TRANSMISSION - NAG1 21 - 135
SHIFT MECHANISM (Continued)

SOLENOID
DESCRIPTION
The typical electrical solenoid used in automotive
applications is a linear actuator. It is a device that
produces motion in a straight line. This straight line
motion can be either forward or backward in direc-
tion, and short or long distance.
A solenoid is an electromechanical device that uses
a magnetic force to perform work. It consists of a coil
of wire, wrapped around a magnetic core made from
steel or iron, and a spring loaded, movable plunger,
which performs the work, or straight line motion.
The solenoids used in transmission applications
are attached to valves which can be classified asnor-
mally openornormally closed. Thenormally
opensolenoid valve is defined as a valve which
allows hydraulic flow when no current or voltage is
applied to the solenoid. Thenormally closedsole-
noid valve is defined as a valve which does not allow
hydraulic flow when no current or voltage is applied
to the solenoid. These valves perform hydraulic con-
trol functions for the transmission and must there-
fore be durable and tolerant of dirt particles. For
these reasons, the valves have hardened steel pop-
pets and ball valves. The solenoids operate the valves
directly, which means that the solenoids must have
very high outputs to close the valves against the siz-
able flow areas and line pressures found in current
transmissions. Fast response time is also necessary
to ensure accurate control of the transmission.
The strength of the magnetic field is the primary
force that determines the speed of operation in a par-
ticular solenoid design. A stronger magnetic field will
cause the plunger to move at a greater speed than a
weaker one. There are basically two ways to increase
the force of the magnetic field:
1. Increase the amount of current applied to the
coil or
2. Increase the number of turns of wire in the coil.
The most common practice is to increase the num-
ber of turns by using thin wire that can completely
fill the available space within the solenoid housing.
The strength of the spring and the length of the
plunger also contribute to the response speed possi-
ble by a particular solenoid design.
A solenoid can also be described by the method by
which it is controlled. Some of the possibilities
include variable force, pulse-width modulated, con-
stant ON, or duty cycle. The variable force and pulse-
width modulated versions utilize similar methods to
control the current flow through the solenoid to posi-
tion the solenoid plunger at a desired position some-
where between full ON and full OFF. The constant
ON and duty cycled versions control the voltage
Fig. 209 Install Bottom Section Of Center
Instrument Panel
1 - SCREW
2 - BOTTOM CENTER PART OF INSTRUMENT PANEL
Fig. 210 Install Top Section Of Center Instrument
Panel
1 - SHIFT LEVER ASSEMBLY FRAME TRIM
2 - STORAGE COMPARTMENT
3 - TOP CENTER PART OF INSTRUMENT PANEL
4 - SCREW
5 - PLUG CONNECTIONS
6 - ASHTRAY
21 - 136 AUTOMATIC TRANSMISSION - NAG1VA
SHIFT MECHANISM (Continued)

across the solenoid to allow either full flow or no flow
through the solenoid's valve.
UPSHIFT/DOWNSHIFT SOLENOID VALVES
The solenoid valves for upshifts and downshifts
(Fig. 211) are located in the shell of the electric con-
trol unit and pressed against the shift plate with a
spring.
The solenoid valves (1) initiate the upshift and
downshift procedures in the shift plate.
The solenoid valves (1) are sealed off from the
valve housing of the shift plate (5) by two O-rings (4,
6). The contact springs (8) at the solenoid valve
engage in a slot in the conductor tracks (7). The force
of the contact spring (8) ensures safe contacts.
MODULATING PRESSURE CONTROL SOLENOID
VALVE
The modulating pressure control solenoid valve
(Fig. 212) is located in the shell of the electric valve
control unit and pressed against the shift plate by a
spring.Its purpose is control the modulating pressure
depending on the continuously changing operating
conditions, such as load and gear change.
The modulating pressure regulating solenoid valve
(1) has an interference fit and is sealed off to the
valve body of the shift plate (4) by a seal (arrow). The
contact springs (2) at the solenoid valve engage in a
slot in the conductor tracks (3). The force of the con-
tact springs (2) ensures secure contacts.
TORQUE CONVERTER LOCKUP CLUTCH PWM
SOLENOID VALVE
The torque converter lockup clutch PWM solenoid
valve (1) (Fig. 213) is located in the shell of the elec-
tric valve control unit and pressed against the shift
plate by a spring.
The PWM solenoid valve (1) for the torque con-
verter lockup controls the pressure for the torque
converter lockup clutch.
The torque converter lockup PWM solenoid valve
(1) is sealed off to the valve body of the shift plate (4)
by an O-ring (5) and a seal (arrow). The contact
springs (2) at the solenoid valve engage in a slot in
the conductor tracks (3). The force of the contact
springs (2) ensures secure contacts.
Fig. 211 Upshift/Downshift Solenoid Valves
1 - UPSHIFT/DOWNSHIFT SOLENOID VALVE
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - O-RING
5 - VALVE HOUSING OF SHIFT PLATE
6 - O-RING
7 - CONDUCTOR TRACK
8 - CONTACT SPRING
Fig. 212 Modulating Pressure Control Solenoid
Valve
1 - MODULATING PRESSURE CONTROL SOLENOID VALVE
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - VALVE HOUSING SHIFT PLATE
5 - CONDUCTOR TRACK
6 - CONTACT SPRING
VAAUTOMATIC TRANSMISSION - NAG1 21 - 137
SOLENOID (Continued)

SHIFT PRESSURE CONTROL SOLENOID VALVE
The shift pressure control solenoid valve (1) (Fig.
214) is located in the shell of the electric valve con-
trol unit and pressed against the shift plate by a
spring.
Its purpose is to control the shift pressure depend-
ing on the continuously changing operating condi-
tions, such as load and gear change.
The shift pressure regulating solenoid valve (1) has
an interference fit and is sealed off to the valve body
of the shift plate (4) by a seal (arrow). The contact
springs (2) at the solenoid valve engage in a slot in
the conductor tracks (3). The force of the contact
springs (2) ensures secure contacts
OPERATION
When an electrical current is applied to the sole-
noid coil, a magnetic field is created which produces
an attraction to the plunger, causing the plunger to
move and work against the spring pressure and the
load applied by the fluid the valve is controlling. The
plunger is normally directly attached to the valve
which it is to operate. When the current is removed
from the coil, the attraction is removed and the
plunger will return to its original position due to
spring pressure.
The plunger is made of a conductive material and
accomplishes this movement by providing a path for
the magnetic field to flow. By keeping the air gap
between the plunger and the coil to the minimum
necessary to allow free movement of the plunger, the
magnetic field is maximized.
Fig. 213 Torque Converter Lockup Clutch PWM
Solenoid Valve
1 - TORQUE CONVERTER LOCKUP CLUTCH PWM SOLENOID
VA LV E
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - VALVE HOUSING OF SHIFT PLATE
5 - O-RING
6 - CONDUCTOR TRACK
7 - CONTACT SPRING
Fig. 214 Shift Pressure Control Solenoid Valve
1 - SHIFT PRESSURE CONTROL SOLENOID VALVE
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - VALVE HOUSING SHIFT PLATE
5 - CONDUCTOR TRACK
6 - CONTACT SPRING
21 - 138 AUTOMATIC TRANSMISSION - NAG1VA
SOLENOID (Continued)

UPSHIFT/DOWNSHIFT SOLENOID VALVES
If a solenoid valve (Fig. 215) is actuated by the
TCM, it opens and guides the control pressure (p-SV)
to the assigned command valve. The solenoid valve
remains actuated and therefore open until the shift-
ing process is complete. The shift pressure (p-SV) to
the command valve is reduced to zero as soon as the
power supply to the solenoid valve is interrupted.
MODULATING PRESSURE CONTROL SOLENOID
VALVE
The modulating pressure regulating solenoid valve
(1) (Fig. 216)assigns a proportional pressure to the
current which is controlled by the TCM according to
the load.
TORQUE CONVERTER LOCKUP CLUTCH PWM
SOLENOID VALVE
The torque converter lockup PWM solenoid (1)
(Fig. 217) valve converts pulse-wave-modulated cur-
rent controlled by the TCM into the appropriate
hydraulic control pressure (p-S/TCC).
SHIFT PRESSURE CONTROL SOLENOID VALVE
The shift pressure regulating solenoid valve (1)
(Fig. 218) assigns a proportional pressure to the cur-
rent which is controlled by the TCM according to the
load.
TEMPERATURE SENSOR/
PARK-NEUTRAL CONTACT
DESCRIPTION
DESCRIPTION - PARK/NEUTRAL CONTACT
The park/neutral contact (4) (Fig. 219) is located in
the shell of the electric control unit and is fixed to
the conductor tracks.
Its purpose is to recognize selector valve and selec-
tor lever positions9P9and9N9. The park/neutral con-
tact consists of:
²the plunger (2).
²the permanent magnet (3).
²the dry-reed contact (4).
Fig. 215 Upshift/Downshift Solenoid Valves
1 - UPSHIFT/DOWNSHIFT SOLENOID VALVE
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - O-RING
5 - VALVE HOUSING OF SHIFT PLATE
6 - O-RING
7 - CONDUCTOR TRACK
8 - CONTACT SPRING
Fig. 216 Modulating Pressure Control Solenoid
Valve
1 - MODULATING PRESSURE CONTROL SOLENOID VALVE
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - VALVE HOUSING SHIFT PLATE
5 - CONDUCTOR TRACK
6 - CONTACT SPRING
VAAUTOMATIC TRANSMISSION - NAG1 21 - 139
SOLENOID (Continued)

DESCRIPTION - TRANSMISSION
TEMPERATURE SENSOR
The transmission oil temperature sensor (1) (Fig.
220) is located in the shell of the electric valve con-
trol unit and is fixed to the conductor tracks.
Its purpose is to measure the temperature of the
transmission oil and pass the temperature to the
TCM as an input signal. It is a temperature-depen-
dent resistor (PTC).
OPERATION
OPERATION - PARK/NEUTRAL CONTACT
In selector lever positions9P9and9N9the park/
neutral contact (4) (Fig. 221) is actuated by a cam
track which is located on the detent plate. The per-
manent magnet (3) is moved away from the dry-reed
contact (4). The dry-reed contact (4) is opened. The
TCM receives an electric signal. The circuit to the
starter in the selector lever positions9P9and9N9is
closed.
Fig. 217 Torque Converter Lockup Clutch PWM
Solenoid Valve
1 - TORQUE CONVERTER LOCKUP CLUTCH PWM SOLENOID
VA LV E
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - VALVE HOUSING OF SHIFT PLATE
5 - O-RING
6 - CONDUCTOR TRACK
7 - CONTACT SPRING
Fig. 218 Shift Pressure Control Solenoid Valve
1 - SHIFT PRESSURE CONTROL SOLENOID VALVE
2 - CONTACT SPRING
3 - CONDUCTOR TRACK
4 - VALVE HOUSING SHIFT PLATE
5 - CONDUCTOR TRACK
6 - CONTACT SPRING
Fig. 219 Park/Neutral Contact
1 - SHELL OF ELECTRIC CONTROL MODULE
2 - PLUNGER
3 - PERMANENT MAGNET
4 - DRY-REED CONTACT
21 - 140 AUTOMATIC TRANSMISSION - NAG1VA
TEMPERATURE SENSOR/PARK-NEUTRAL CONTACT (Continued)