clutch MERCEDES-BENZ SPRINTER 2006 Service Manual

MODULATING PRESSURE CONTROL SOLENOID
VALVE
The modulating pressure control solenoid valve (1)
(Fig. 230) 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. 231) 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. 230 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
Fig. 231 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
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 173

MODULATING PRESSURE CONTROL SOLENOID
VALVE
The modulating pressure regulating solenoid valve
(1) (Fig. 234) 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. 235) valve converts pulse-wave-modulated cur-
rent controlled by the TCM into the appropriate
hydraulic control pressure (p-S/TCC).
Fig. 234 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
Fig. 235 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
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 175

Refer to the Transmission Temperature Sensor
Specifications table (Fig. 241) for the relationship
between transmission temperature, sensor voltage,
and sensor resistance.
TORQUE CONVERTER
DESCRIPTION
CAUTION: The torque converter must be replaced if
a transmission failure resulted in large amounts of
metal or fiber contamination in the fluid.
The torque converter (Fig. 242) is a hydraulic
device that couples the engine crankshaft to the
transmission. The torque converter consists of an
outer shell with an internal turbine (1), a stator (3),
an overrunning clutch, an impeller (2), and an elec-
tronically applied converter clutch. The converter
clutch provides reduced engine speed and greater
fuel economy when engaged. Clutch engagement also
provides reduced transmission fluid temperatures.
The converter clutch engages in third through fifth
gears. The torque converter hub drives the transmis-
sion oil (fluid) pump.
A turbine damper (6) has been added for some
applications to help improve vehicle noise, vibration,
and harshness (NVH) characteristics.
The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
Fig. 241 Transmission Temperature Sensor
Specifications
Fig. 242 Torque Converter
1 - TURBINE
2 - IMPELLER
3-STATOR
4 - INPUT SHAFT
5 - STATOR SHAFT
6 - TURBINE DAMPER
21 - 178 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

STATOR
The stator assembly (1-4) (Fig. 245) is mounted on
a stationary shaft which is an integral part of the oil
pump.
The stator (1) is located between the impeller (2)
and turbine (4) within the torque converter case (Fig.
246). The stator contains a freewheeling clutch,
which allows the stator to rotate only in a clockwise
direction. When the stator is locked against the free-wheeling clutch, the torque multiplication feature of
the torque converter is operational.
TORQUE CONVERTER CLUTCH (TCC)
The TCC (9) (Fig. 247) was installed to improve
the efficiency of the torque converter that is lost to
the slippage of the fluid coupling. Although the fluid
coupling provides smooth, shock-free power transfer,
it is natural for all fluid couplings to slip. If the
impeller and turbine were mechanically locked
together, a zero slippage condition could be obtained.
A hydraulic piston with friction material was added
to the turbine assembly to provide this mechanical
lock-up.
In order to reduce heat build-up in the transmis-
sion and buffer the powertrain against torsional
vibrations, the TCM can duty cycle the torque con-
verter lock-up solenoid to achieve a smooth applica-
tion of the torque converter clutch. This function,
referred to as Electronically Modulated Converter
Clutch (EMCC) can occur at various times depending
on the following variables:
²Shift lever position
²Current gear range
Fig. 245 Stator Components
1 - CAM (OUTER RACE)
2 - ROLLER
3 - SPRING
4 - INNER RACE
Fig. 246 Stator Location
1-STATOR
2 - IMPELLER
3 - FLUID FLOW
4 - TURBINE
Fig. 247 Torque Converter Lock-up Clutch
1 - TURBINE
2 - IMPELLER
3-STATOR
4 - INPUT SHAFT
5 - STATOR SHAFT
6 - PISTON
7 - COVER SHELL
8 - INTERNALLY TOOTHED DISC CARRIER
9 - CLUTCH PLATE SET
10 - EXTERNALLY TOOTHED DISC CARRIER
11 - TURBINE DAMPER
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 181

²Transmission fluid temperature
²Engine coolant temperature
²Input speed
²Throttle angle
²Engine speed
OPERATION
The converter impeller (driving member) (2) (Fig.
248), which is integral to the converter housing and
bolted to the engine drive plate, rotates at engine
speed. The converter turbine (driven member) (1),
which reacts from fluid pressure generated by the
impeller, rotates and turns the transmission input
shaft (4).
TURBINE
As the fluid that was put into motion by the impel-
ler blades strikes the blades of the turbine, some of
the energy and rotational force is transferred into the
turbine and the input shaft. This causes both of them
(turbine and input shaft) to rotate in a clockwise
direction following the impeller. As the fluid is leav-
ing the trailing edges of the turbine's blades it con-
tinues in a ªhinderingº direction back toward the
impeller. If the fluid is not redirected before it strikes
the impeller, it will strike the impeller in such a
direction that it would tend to slow it down.
STATOR
Torque multiplication is achieved by locking the
stator's over-running clutch to its shaft. (Fig. 249)
Under stall conditions (the turbine is stationary), the
oil leaving the turbine blades strikes the face of the
stator blades and tries to rotate them in a counter-
clockwise direction. When this happens the over-run-
ning clutch of the stator locks and holds the stator
from rotating. With the stator locked, the oil strikes
the stator blades and is redirected into a ªhelpingº
direction before it enters the impeller. This circula-
tion of oil from impeller to turbine, turbine to stator,
and stator to impeller, can produce a maximum
torque multiplication of about 2.0:1. As the turbine
begins to match the speed of the impeller, the fluid
that was hitting the stator in such as way as to
cause it to lock-up is no longer doing so. In this con-
dition of operation, the stator begins to free wheel
and the converter acts as a fluid coupling.
Fig. 248 Torque Converter
1 - TURBINE
2 - IMPELLER
3-STATOR
4 - INPUT SHAFT
5 - STATOR SHAFT
6 - TURBINE DAMPER
Fig. 249 Stator Operation
1 - DIRECTION STATOR WILL FREE WHEEL DUE TO OIL
PUSHING ON BACKSIDE OF VANES
2 - FRONT OF ENGINE
3 - INCREASED ANGLE AS OIL STRIKES VANES
4 - DIRECTION STATOR IS LOCKED UP DUE TO OIL PUSHING
AGAINST STATOR VANES
21 - 182 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller (2)
and turbine (1) are rotating at about the same speed
and the stator (3) is freewheeling, providing no
torque multiplication. By applying the turbine's pis-
ton and friction material (9) (Fig. 250), a total con-
verter engagement can be obtained. The result of this
engagement is a direct 1:1 mechanical link between
the engine and the transmission.
The clutch can be engaged in second, third, fourth,
and fifth gear ranges.
The TCM controls the torque converter by way of
internal logic software. The programming of the soft-
ware provides the TCM with control over the torque
converter solenoid. There are four output logic states
that can be applied as follows:
²No EMCC
²Partial EMCC
²Full EMCC
²Gradual-to-no EMCC
NO EMCC
Under No EMCC conditions, the TCC Solenoid is
OFF. There are several conditions that can result inNO EMCC operations. No EMCC can be initiated
due to a fault in the transmission or because the
TCM does not see the need for EMCC under current
driving conditions.
PARTIAL EMCC
Partial EMCC operation modulates the TCC Sole-
noid (duty cycle) to obtain partial torque converter
clutch application. Partial EMCC operation is main-
tained until Full EMCC is called for and actuated.
During Partial EMCC some slip does occur. Partial
EMCC will usually occur at low speeds, low load and
light throttle situations.
FULL EMCC
During Full EMCC operation, the TCM increases
the TCC Solenoid duty cycle to full ON after Partial
EMCC control brings the engine speed within the
desired slip range of transmission input speed rela-
tive to engine rpm.
GRADUAL - TO - NO EMCC
This operation is to soften the change from Full or
Partial EMCC to No EMCC. This is done at mid-
throttle by decreasing the TCC Solenoid duty cycle.
REMOVAL
(1) Remove transmission and torque converter
from vehicle.
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the
lifting device or work surface, the center of gravity
of the transmission will shift when the torque con-
verter is removed creating an unstable condition.
The torque converter is a heavy unit. Use caution
when separating the torque converter from the
transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
Fig. 250 Torque Converter Lock-up Clutch
1 - TURBINE
2 - IMPELLER
3-STATOR
4 - INPUT SHAFT
5 - STATOR SHAFT
6 - PISTON
7 - COVER SHELL
8 - INTERNALLY TOOTHED DISC CARRIER
9 - CLUTCH PLATE SET
10 - EXTERNALLY TOOTHED DISC CARRIER
11 - TURBINE DAMPER
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 183

When the outside air contains smoke, odors, high
humidity, or if rapid cooling is desired, interior air
can by recirculated by selecting the Recirculation
Mode with the mode control knob. The mode control
knob operates the recirculation door through use of a
vacuum actuator. When the Recirculation Mode is
selected, the recirculation door is closed to prevent
outside air from entering the passenger compart-
ment.
To maintain minimum evaporator temperature and
prevent evaporator freezing, an evaporator tempera-
ture sensor is used.
The A/C system is designed for the use of non-CFC,
R-134a refrigerant only and uses an expansion valve
to meter refrigerant flow to the evaporator.
DIAGNOSIS AND TESTING
A / C PERFORMANCE
The A/C system is designed to provide the passen-
ger compartment with low temperature and low
humidity air. The A/C evaporator, located in the
HVAC housing is cooled to temperatures near the
freezing point. As warm damp air passes over the
fins of the A/C evaporator, the air transfers its heat
to the refrigerant in the evaporator coils and the
moisture in the air condenses on the evaporator fins.
During periods of high heat and humidity, an A/C
system will be more effective in the Recirculation
mode (max-A/C). With the system in the Recircula-
tion mode, only air from the passenger compartment
passes through the A/C evaporator. As the passenger
compartment air dehumidifies, the A/C system per-
formance levels rise.
Humidity has an important bearing on the temper-
ature of the air delivered to the interior of the vehi-
cle. It is important to understand the effect that
humidity has on the performance of the A/C system.
When humidity is high, the A/C evaporator has to
perform a double duty. It must lower the air temper-
ature, and it must lower the temperature of the
moisture in the air that condenses on the evaporator
fins. Condensing the moisture in the air transfers
heat energy into the evaporator fins and coils. This
reduces the amount of heat the A/C evaporator can
absorb from the air. High humidity greatly reduces
the ability of the A/C evaporator to lower the temper-
ature of the air.
However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Wring-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from their
A/C system on humid days. A performance test is the
best way to determine whether the system is per-
forming up to design standards. This test also pro-
vides valuable clues as to the possible cause oftrouble with the A/C system. The ambient air tem-
perature in the location where the vehicle will be
tested must be a minimum of 21É C (70É F) for this
test.
A / C PERFORMANCE TEST
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
NOTE: Very specific instructions and conditions
pertain to this procedure which are significantly dif-
ferent than procedures used in other vehicle appli-
cations. Follow each step in the order they are
presented. Do not skip steps or change conditions
from those stated or results will be adversely
affected and invalid.
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Check for diagnostic trouble codes using a
DRBIIItscan tool. If no DTCs are found in the
engine control module (ECM), go to Step 2. If any
DTCs are found, repair as required, then proceed to
Step 2.
(2) Place the vehicle in the shade and operate the
heating-A/C system under the following conditions.
²Engine at idle at operating temperature
²All doors or windows open
²Transaxle in Neutral
²All A/C duct louvers open
²A/C-heater controls set to fresh air (NOT Recir-
culate), full cool, panel mode, high blower and with
A/C compressor engaged.
NOTE: The A/C compressor clutch is de-energized
under any of the following conditions:
²Restricted compressor (thermal fuse in the pul-
ley)
²Low pressure in the system
²Low evaporator temperature
²Hard acceleration (WOT)
²High coolant temperatures
(3) Insert a thermometer in the driver side center
panel air outlet and operate the A/C system until the
thermometer temperature stabilizes.
VAHEATING & AIR CONDITIONING 24 - 3

(4) With the A/C compressor clutch engaged, duct
temperature should not be less than 2É C (35É F) or
more than 12É C (54É F). The compressor clutch may
cycle, depending upon the ambient temperature and
humidity. If the clutch cycles, use the readings
obtained before the clutch disengaged.
(5) If the A/C compressor clutch has not cycled off
and the duct temperature is less than 2É C (35É F),
check the evaporator temperature sensor and circuitby performing the ATC Function Test (Refer to 24 -
HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - ATC FUNCTION TEST).
(6) If the air outlet temperature fails to meet the
specifications, refer to the A/C System Diagnosis
chart.
A/C SYSTEM DIAGNOSIS
Condition Possible Causes Correction
Rapid A/C compressor clutch
cycling (ten or more cycles
per minute).Very low refrigerant system
charge.See Refrigerant System Leaks in this group.
Test the refrigerant system for leaks. Repair,
evacuate and charge the refrigerant system, if
required.
Equal pressures, but the
compressor clutch does not
engage.1. No refrigerant in the refrig-
erant system.1. See Refrigerant System Leaks in this
group. Test the refrigerant system for leaks.
Repair, evacuate and charge the refrigerant
system, if required.
2. Faulty fuse. 2. Check the fuses in the Power distribution
block and junction block. Repair the shorted
circuit or component and replace the fuses, if
required. Refer to Group 8.
3. Faulty A/C compressor
clutch coil.3. See A/C Compressor Clutch Coil in this
group. Test the compressor clutch coil and
replace, if required.
4. Improperly installed or faulty
evaporator temperature sensor.4. See Evaporator Temperature Sensor in this
group. Test the sensor and replace, if re-
quired.
5. Faulty A/C pressure trans-
ducer.5. See A/C Pressure Transducer in this
group. Test the sensor and replace, if re-
quired.
6. Faulty engine Control Mod-
ule (ECM).6. Refer to Group 9 - Engine Electrical Diag-
nostics for testing of the ECM. Test the ECM
and replace, if required.
Normal pressures, but A/C
Performance Test air temper-
atures at center panel outlet
are too high.1. Excessive refrigerant oil in
system.1. See Refrigerant Oil Level in this group.
Recover the refrigerant from the refrigerant
system and inspect the refrigerant oil content.
Restore the refrigerant oil to the proper level,
if required.
2. Blend door cable improperly
installed or faulty.2. See Mode Door Cables in this group. In-
spect the cable for proper operation and re-
place, if required.
3. Blend-air door(s) inoperative
or sealing improperly.3. See HVAC Housing in this group. Inspect
the blend-air door(s) for proper operation and
sealing. Repair if required.
24 - 4 HEATING & AIR CONDITIONINGVA

Item Description Notes
Low psi Control A/C Pressure
TransducerLiquid line
mounted -
input to PCM
- operating
range of 200
kPa (29 psi)
to 2799 kPa
(406 psi)
High psi Con-
trolHigh Pressure
Relief ValveReceiver/drier
mounted -
opens at a
discharge
pressure over
3999 kPa
(580 psi)
Refrigerant
Charge Capaci-
tyRefer to the A/C
Underhood Spec-
ification Label
located in the
engine compart-
mentR-134a refrig-
erant
A/C Clutch Coil
Draw2.0-3.7 amps @
12V   0.5V @
21É C (70É F)
A/C Clutch Air
Gap0.5 - 0.88 mm
(0.020 - 0.035
in.)
REAR A/C SYSTEM
Item Description Notes
A/C Compres-
sorDenso 10S17 ND-8 PAG oil
Freeze-up Con-
trolEvaporator Tem-
perature SensorInput to rear
A/C control
module -
evaporator fin
mounted -
cycles clutch
off below 1.6É
C (35É F),
cycles clutch
back on
above 3.9É C
(39É F)
Low psi Control A/C Low Pres-
sure SwitchInput to rear
A/C control
module - suc-
tion line
mounted -
cycles clutch
off below 30
kPa (4.4 psi)
Item Description Notes
High psi Con-
trolA/C High Pres-
sure SwitchInput to rear
A/C control
module - con-
denser inlet
tube mounted
- cycles clutch
off above
2551 kPa
(370 psi)
Refrigerant
Charge Capaci-
tyRefer to the Rear
A/C Specification
LabelR-134a refrig-
erant
A/C Clutch Coil
Draw3.3 amps @ 12V
  0.5V @ 21É C
(70É F)
A/C Clutch Air
Gap0.35 - 0.60 mm
(0.014 - 0.024
in.)
VAHEATING & AIR CONDITIONING 24 - 7

CONTROLS - FRONT
TABLE OF CONTENTS
page page
A/C COMPRESSOR CLUTCH
DESCRIPTION..........................8
OPERATION............................9
STANDARD PROCEDURE
A/C COMPRESSOR CLUTCH AIR GAP......9
A/C COMPRESSOR CLUTCH BREAK-IN.....9
REMOVAL.............................9
INSPECTION..........................11
INSTALLATION.........................11
A/C COMPRESSOR CLUTCH COIL
DIAGNOSIS AND TESTING
A/C COMPRESSOR CLUTCH COIL........12
A/C HEATER CONTROL
DESCRIPTION.........................12
OPERATION...........................13
REMOVAL.............................13
INSTALLATION.........................13
A/C PRESSURE TRANSDUCER
DESCRIPTION.........................14
OPERATION...........................14
DIAGNOSIS AND TESTING
A/C PRESSURE TRANSDUCER..........14
REMOVAL.............................15
INSTALLATION.........................15
AIR OUTLET TEMPERATURE SENSOR
DESCRIPTION.........................16
OPERATION...........................16
REMOVAL.............................16
INSTALLATION.........................16
AMBIENT TEMPERATURE SENSOR
DESCRIPTION.........................17
OPERATION...........................17REMOVAL.............................17
INSTALLATION.........................17
BLOWER MOTOR RESISTOR
DESCRIPTION.........................17
OPERATION...........................18
DIAGNOSIS AND TESTING
BLOWER MOTOR RESISTOR............18
REMOVAL.............................18
INSTALLATION.........................18
BLOWER MOTOR SWITCH
DESCRIPTION.........................19
OPERATION...........................19
DIAGNOSIS AND TESTING
BLOWER MOTOR SWITCH..............19
EVAPORATOR TEMPERATURE SENSOR
DESCRIPTION.........................19
OPERATION...........................19
REMOVAL.............................20
INSTALLATION.........................20
IN-CAR TEMPERATURE SENSOR
DESCRIPTION.........................21
OPERATION...........................21
DIAGNOSIS AND TESTING
IN-CAR TEMPERATURE SENSOR.........21
MODE DOOR CABLES
REMOVAL.............................21
INSTALLATION.........................21
RECIRCULATION DOOR ACTUATOR
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................22
INSTALLATION.........................23
A / C COMPRESSOR CLUTCH
DESCRIPTION
The A/C compressor clutch assembly consists of a
stationary electromagnetic field coil, a hub bearing
and pulley assembly, and a clutch plate (Fig. 1). The
field coil and the hub bearing and pulley assembly
are each retained on the nose of the compressor front
housing with snap rings. The clutch plate is splined
to the compressor shaft and secured with a bolt.
The compressor clutch plate and pulley and the
clutch field coil are available for service replace-
ment.
24 - 8 CONTROLS-FRONTVA