service MERCEDES-BENZ SPRINTER 2006 Service Manual

ACCELERATOR PEDAL POSI-
TION SENSOR
DESCRIPTION
The accelerator pedal position sensor (Fig. 1) is
located on the accelerator pedal assembly. The driver
supplies the torque requirements for the engine by
operating the accelerator pedal in accordance with
the desired speed or acceleration. The pedal sensor
converts the mechanical operation of the pedal into
an electrical signal and sends the information to the
ECM. The ECM adjusts the quantity of the fuel that
is injected into the engine.
The accelerator pedal position sensor is serviced as
an assembly with the accelerator pedal assembly.
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the APP sensor electrical connec-
tors.
(3) Remove the APP sensor fasteners and the sen-
sor (Fig. 2).
INSTALLATION
(1) Connect the accelerator pedal position sensor
wiring harness connector.
Fig. 1 ACCELERATOR PEDAL POSITION SENSOR
1 - APP SENSOR
2 - ACCELERATOR PEDAL
3 - BRAKE PEDAL
Fig. 2 ACCELERATOR PEDAL POSITION SENSOR
1 - APP SENSOR
2 - ACCELERATOR PEDAL
3 - BRAKE PEDAL
Fig. 3 ACCELERATOR PEDAL POSITION SENSOR
1 - APP SENSOR
2 - ACCELERATOR PEDAL
3 - BRAKE PEDAL
14 - 32 FUEL INJECTIONVA

INSTALLATION
(1) (Refer to 14 - FUEL SYSTEM/FUEL INJEC-
TION - WARNING) Install the sealing ring on to the
sensor (Fig. 14).
(2) Screw the sensor in to the fuel rail. Counter-
hold the threaded connection and tighten the sensor
to 18 lbs. ft. (25 N´m.) (Fig. 14).
(3) Connect the wiring harness to the sensor.
(4) Install the mixing housing.
CAUTION: Care must be taken when installing the
engine cover. Assure the proper routing of the fuel
injector return fuel hose to the banjo bolt fitting in
the left rear corner of the cover. Failure to do so
may pinch or damage the hose causing fuel leakage
or a driveability concern.
(5) Connect negative battery cable.
FUEL PRESSURE SOLENOID
DESCRIPTION
The fuel pressure solenoid is attached to the rear
of the fuel rail. A sealing metal disc seals the valve to
the rail. The seal is not serviceable and looses it's
sealing properties upon removal of the solenoid.
Therefore, the solenoid must be replaced when ever
it is removed from the rail. The solenoid controls and
maintains the rail pressure constant along with a
control current transmitted by the engine control
module (ECM) (Fig. 15).
OPERATION
High pressure which is present in the fuel rail
flows to the ball seat of the pressure solenoid (Fig.
16). The specified pressure required by the system is
built up in the rail by the fuel pressure solenoid
building up a magnetic force which corresponds to
this specific pressure by means of a control current
from the electronic control module (ECM) (Fig. 16).
This magnetic force equals a certain outlet cross sec-
tion at the ball seat of the valve. The rail pressure is
altered as a result of the quantity of fuel which flows
off (Fig. 16). The current fuel pressure is signaled by
the fuel rail pressure sensor to the engine control
module (ECM). The controlled fuel flows back along
the return fuel line, into the tank.
In a de-energized state, the fuel pressure solenoid
is closed as the spring force presses the ball into the
ball seat (Fig. 16). When driving, the fuel pressure
solenoid is constantly open (Fig. 16). When engine is
started, the fuel pressure solenoid is held closed by
magnetic force (Fig. 16). When driving, the pressure
of the fluid counteracts the magnetic force of the coil
and the slight spring force (Fig. 16).
Fig. 15 FUEL PRESSURE SOLENOID
1 - FUEL PRESSURE SENSOR
2 - FUEL RAIL
3 - FUEL PRESSURE SOLENOID
Fig. 16 FUEL PRESSURE SOLENOID OPERATION
1 - BALL SEAT
2 - SPRING FORCE
3 - MAGNETIC FORCE
4 - COIL
5 - FUEL PRESSURE SOLENOID
6 - HIGH PRESSURE SUPPLY
14 - 40 FUEL INJECTIONVA

INSTALLATION
(1) Position the MAF sensor to air cleaner housing
and install the retaining screws (Fig. 24).
(2) Connect the air intake hose to the MAF sensor
and tighten clamp.
(3) connect the MAF wiring harness connector.
(4) Connect negative battery cable.
O2 SENSOR
DESCRIPTION
The wide band oxygen sensor measures the oxygen
content in the exhaust gas to monitor EGR. The sen-
sor is mounted in the exhaust pipe at a 30 degree
angle to prevent the collection of moisture between
the sensor housing and element. The sensor is
located close to the turbocharger for a quicker
response time.
The oxygen sensor has five wires (heater power
and ground, reference voltage, and 2 wires for a
pump cell). The oxygen sensor connects to a six wire
harness connector. A non serviceable trimming resis-
tor is built into the sensor connector. The resistance
is dependent on the over all length and type of sen-
sor.
OPERATION
The O2 sensor is a planar zirconium dioxide (ZrO2)
dual cell limiting current probe with a integralheater. The term wide ban, refers to the ability of the
O2 sensor to generate a clear signal over a wide air-
fuel ratio measuring range. As a dual sensor, it incor-
porates a second O2 chamber (oxygen pump cell),
which requires a separate voltage supply.
The sensor element combines a sensor cell (8) and
an oxygen pump cell (9). Both cells are made of zir-
conium-dioxide (ZrO2) and are coated with porous
platinum electrodes. The sensor cell operates just
like a typical O2 sensor. The oxygen pump cell trans-
port oxygen ions when voltage is applied.
A gas sample chamber (5) is sandwiched between
the oxygen pump cell and the sensor cell. A pump
electrode and sensor cell electrode are located in the
sample chamber. A sample passage (10) connects the
sample chamber to the surrounding exhaust gas. A
sensor cell electrode is located in the reference air
channel (6), which connects to the outside air (Fig.
25).
Fig. 24 MANIFOLD AIR FLOW SENSOR
1 - WIRING HARNESS
2 - AIR INTAKE HOSE
3 - CLAMP
4 - MAF SENSOR
5 - AIR CLEANER HOUSING
VAFUEL INJECTION 14 - 45

PUMP
TABLE OF CONTENTS
page page
PUMP
DESCRIPTION.........................11
OPERATION...........................11
DIAGNOSIS AND TESTING - PUMP LEAKAGE . 11
STANDARD PROCEDURE
STANDARD PROCEDURE - POWER
STEERING PUMP - INITIAL OPERATION....11
STANDARD PROCEDURE - FLUSHING
POWER STEERING SYSTEM............12
REMOVAL.............................12
INSTALLATION.........................12
SPECIFICATIONS - TORQUE CHART........13
FLUID
STANDARD PROCEDURE
POWER STEERING PUMP FILL AND BLEED
PROCEDURE........................13FLUID COOLER TUBE
REMOVAL.............................13
INSTALLATION.........................13
HOSES
REMOVAL
REMOVAL - PRESSURE HOSE...........14
REMOVAL - RETURN LINE FROM PUMP TO
COOLER TUBE.......................14
REMOVAL - RETURN HOSE FROM GEAR
TO COOLER TUBE....................14
INSTALLATION
INSTALLATION - PRESSURE HOSE.......14
INSTALLATION - RETURN LINE FROM
PUMP TO COOLER TUBE...............14
INSTALLATION - RETURN HOSE FROM
GEAR TO COOLER TUBE...............14
PUMP
DESCRIPTION
CAUTION: Use approved fluid only in the power
steering system (Refer to LUBRICATION & MAINTE-
NANCE/FLUID TYPES - DESCRIPTION). No other
power steering or automatic transmission fluid is to
be used in the system. Damage may result to the
power steering pump and system if any other fluid
is used, and do not overfill.
The pump is connected to the steering gear via the
pressure hose and the return hose. The pump shaft
has a pressed-on pulley that is belt driven by the
crankshaft pulley.
All vehicles are equipped with a power steering
fluid cooler.
NOTE: Power steering pumps are not interchange-
able with pumps installed on other vehicles.
OPERATION
Hydraulic pressure is provided for the power steer-
ing gear by the belt driven power steering pump. The
power steering pumps are constant flow rate and dis-
placement, vane-type pumps.
DIAGNOSIS AND TESTING - PUMP LEAKAGE
The pump is serviced as an assembly and should
not be disassembled. The plastic pump reservoir and
the reservoir o-rings can be replaced.Check for leaks in the following areas:
²Pump shaft seal behind the pulley
²Pump to reservoir O-ring
²Reservoir cap
²Pressure and return lines
²Flow control valve fitting
STANDARD PROCEDURE
STANDARD PROCEDURE - POWER STEERING
PUMP - INITIAL OPERATION
WARNING: THE FLUID LEVEL SHOULD BE
CHECKED WITH ENGINE OFF TO PREVENT INJURY
FROM MOVING COMPONENTS.
CAUTION: Use approved fluid only in the power
steering system (Refer to LUBRICATION & MAINTE-
NANCE/FLUID TYPES - DESCRIPTION). No other
power steering or automatic transmission fluid is to
be used in the system. Damage may result to the
power steering pump and system if any other fluid
is used, and do not overfill.
Wipe filler cap clean, then check the fluid level.
The dipstick should indicateCOLDwhen the fluid is
at normal temperature.
(1) Turn steering wheel all the way to the left
(2) Fill the pump fluid reservoir to the proper level
and let the fluid settle for at least two (2) minutes.
(3) Raise the front wheels off the ground.
VAPUMP 19 - 11

TRANSMISSION
TABLE OF CONTENTS
page
AUTOMATIC TRANSMISSION NAG1 - SERVICE
INFORMATION............................1
AUTOMATIC TRANSMISSION NAG1 - SERVICE
INFORMATION
TABLE OF CONTENTS
page page
AUTOMATIC TRANSMISSION NAG1 - SERVICE
INFORMATION
DESCRIPTION..........................3
OPERATION............................4
DIAGNOSIS AND TESTING
AUTOMATIC TRANSMISSION............39
PRELIMINARY........................39
ROAD TESTING......................39
AUTOMATIC TRANSMISSION............40
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR......................42
REMOVAL.............................42
DISASSEMBLY.........................46
ASSEMBLY............................52
INSTALLATION.........................60
SCHEMATICS AND DIAGRAMS............65
SPECIFICATIONS - NAG1 AUTOMATIC
TRANSMISSION......................86
SPECIAL TOOLS - AUTOMATIC
TRANSMISSION - NAG1................87
INPUT CLUTCHES
DESCRIPTION.........................90
OPERATION...........................91
INPUT CLUTCH K1
DISASSEMBLY.........................92
ASSEMBLY............................94
INPUT CLUTCH K2
DISASSEMBLY.........................97
ASSEMBLY............................99
INPUT CLUTCH K3
DISASSEMBLY........................102
ASSEMBLY...........................103
ELECTROHYDRAULIC UNIT
DESCRIPTION........................105
OPERATION..........................112
REMOVAL............................120
DISASSEMBLY........................121
ASSEMBLY...........................125INSTALLATION........................129
FLUID AND FILTER
DESCRIPTION........................131
OPERATION..........................131
DIAGNOSIS AND TESTING
EFFECTS OF INCORRECT FLUID LEVEL . . 131
CAUSES OF BURNT FLUID.............132
FLUID CONTAMINATION...............132
STANDARD PROCEDURE
CHECK OIL LEVEL...................132
TRANSMISSION FILL.................133
FLUID/FILTER SERVICE...............134
FREEWHEELING CLUTCH
DESCRIPTION........................135
OPERATION..........................135
DISASSEMBLY........................136
ASSEMBLY...........................138
GEARSHIFT CABLE
DIAGNOSIS AND TESTING
GEARSHIFT CABLE..................138
REMOVAL............................139
INSTALLATION........................140
HOLDING CLUTCHES
DESCRIPTION........................141
OPERATION..........................142
HOLDING CLUTCH B1
DISASSEMBLY........................143
ASSEMBLY...........................145
HOLDING CLUTCH B2
DISASSEMBLY........................148
ASSEMBLY...........................150
INPUT SPEED SENSORS
DESCRIPTION........................153
OPERATION..........................154
OIL PUMP
DESCRIPTION........................154
OPERATION..........................154
DISASSEMBLY........................155
VATRANSMISSION 21 - 1

INSPECTION.........................155
ASSEMBLY...........................156
OUTPUT SHAFT BEARING
REMOVAL............................156
INSTALLATION........................158
OUTPUT SHAFT SEAL
REMOVAL............................159
INSTALLATION........................159
PARK LOCK CABLE
REMOVAL............................160
INSTALLATION........................161
PISTONS
DESCRIPTION........................163
OPERATION..........................163
PLANETARY GEARTRAIN
DESCRIPTION........................164
OPERATION..........................165
DISASSEMBLY........................166
ASSEMBLY...........................167
SHIFT MECHANISM
DESCRIPTION........................168
OPERATION..........................168REMOVAL............................169
INSTALLATION........................170
SOLENOID
DESCRIPTION........................171
OPERATION..........................174
TEMPERATURE SENSOR/PARK-NEUTRAL
CONTACT
DESCRIPTION
PARK/NEUTRAL CONTACT.............176
TRANSMISSION TEMPERATURE SENSOR . 176
OPERATION
PARK/NEUTRAL CONTACT.............177
TRANSMISSION TEMPERATURE SENSOR . 177
TORQUE CONVERTER
DESCRIPTION........................178
OPERATION..........................182
REMOVAL............................183
INSTALLATION........................184
TORQUE CONVERTER HUB SEAL
REMOVAL............................184
INSTALLATION........................184
21 - 2 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION
DESCRIPTION
The NAG1 automatic transmission (Fig. 1) is an
electronically controlled 5-speed transmission with a
lock-up clutch in the torque converter. The ratios for
the gear stages are obtained by 3 planetary gear sets.
Fifth gear is designed as an overdrive with a high-
speed ratio.
NAG1 identifies a family of transmissions and
means ªNºew ªAºutomatic ªGºearbox, generation 1.
Various marketing names are associated with the
NAG1 family of transmissions, depending on the
transmisson variation being used in a specific vehi-
cle. Some examples of the marketing names are:
W5A300, W5A380, and W5A580. The marketing
name can be interpreted as follows:
²W = A transmission using a hydraulic torque
converter.
²5 = 5 forward gears.
²A = Automatic Transmission.²580 = Maximum input torque capacity in New-
ton meters.
The gears are actuated electronically/hydraulically.
The gears are shifted by means of an appropriate
combination of three multi-disc holding clutches,
three multi-disc driving clutches, and two freewheel-
ing clutches.
Electronic transmission control enables precise
adaptation of pressures to the respective operating
conditions and to the engine output during the shift
phase which results in a significant improvement in
shift quality.
Furthermore, it offers the advantage of a flexible
adaptation to various vehicle and engines.
Basically, the automatic transmission with elec-
tronic control offers the following advantages:
²Reduces fuel consumption.
²Improved shift comfort.
²More favourable step-up through the five gears.
Fig. 1 NAG1 Automatic Transmission
1 - TORQUE CONVERTER 11 - PARKING LOCK GEAR
2 - OIL PUMP 12 - INTERMEDIATE SHAFT
3 - DRIVESHAFT 13 - FREEWHEEL F2
4 - MULTI-DISC HOLDING CLUTCH B1 14 - REAR PLANETARY GEAR SET
5 - DRIVING CLUTCH K1 15 - CENTER PLANETARY GEAR SET
6 - DRIVING CLUTCH K2 16 - ELECTROHYDRAULIC CONTROL UNIT
7 - MULTI-DISC HOLDING CLUTCH B3 17 - FRONT PLANETARY GEAR SET
8 - DRIVING CLUTCH K3 18 - FREEWHEEL F1
9 - MULTI-DISC HOLDING CLUTCH B2 19 - STATOR SHAFT
10 - OUTPUT SHAFT 20 - TORQUE CONVERTER LOCK-UP CLUTCH
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 3

²Increased service life and reliability.
²Lower maintenance costs.
TRANSMISSION IDENTIFICATION
The transmission can be generically identified
visually by the presence of a round 13-way connector
located near the front corner of the transmission oil
pan, on the right side. Specific transmission informa-
tion can be found stamped into a pad on the left side
of the transmission, above the oil pan rail.
TRANSMISSION GEAR RATIOS
The gear ratios for the NAG1 automatic transmis-
sion are as follows:
1st Gear............................3.59:1
2nd Gear............................2.19:1
3rd Gear............................1.41:1
4th Gear............................1.00:1
5th Gear............................0.83:1
Reverse.............................3.16:1
TRANSMISSION HOUSING
The converter housing and transmission are made
from a light alloy. These are bolted together and cen-
tered via the outer multi-disc carrier of multi-disc
holding clutch, B1. A coated intermediate plate pro-
vides the sealing. The oil pump and the outer multi-
disc carrier of the multi-disc holding clutch, B1, are
bolted to the converter housing. The stator shaft is
pressed into it and prevented from rotating by
splines. The electrohydraulic unit is bolted to the
transmission housing from underneath. A sheet
metal steel oil pan forms the closure.
MECHANICAL SECTION
The mechanical section consists of a input shaft,
output shaft, a sun gear shaft, and three planetary
gear sets which are coupled to each other. The plan-
etary gear sets each have four planetary pinion
gears. The oil pressure for the torque converter
lock-up clutch and clutch K2 is supplied through
bores in the input shaft. The oil pressure to clutch
K3 is transmitted through the output shaft. The
lubricating oil is distributed through additional bores
in both shafts. All the bearing points of the gear sets,
as well as the freewheeling clutches and actuators,
are supplied with lubricating oil. The parking lock
gear is connected to the output shaft via splines.
Freewheeling clutches F1 and F2 are used to opti-
mize the shifts. The front freewheel, F1, is supported
on the extension of the stator shaft on the transmis-
sion side and, in the locking direction, connects the
sun gear of the front planetary gear set to the trans-
mission housing. In the locking direction, the rear
freewheeling clutch, F2, connects the sun gear of the
center planetary gear set to the sun gear of the rear
planetary gear set.
ELECTROHYDRAULIC CONTROL UNIT
The electrohydraulic control unit comprises the
shift plate made from light alloy for the hydraulic
control and an electrical control unit. The electrical
control unit comprises of a supporting body made of
plastic, into which the electrical components are
assembled. The supporting body is mounted on the
shift plate and screwed to it.
Strip conductors inserted into the supporting body
make the connection between the electrical compo-
nents and a plug connector. The connection to the
wiring harness on the vehicle and the transmission
control module (TCM) is produced via this 13-pin
plug connector with a bayonet lock.
SHIFT GROUPS
The hydraulic control components (including actua-
tors) which are responsible for the pressure distribu-
tion before, during, and after a gear change are
described as a shift group. Each shift group contains
a command valve, a holding pressure shift valve, a
shift pressure shift valve, overlap regulating valve,
and a solenoid.
The hydraulic system contains three shift groups:
1-2/4-5, 2-3, and 3-4. Each shift group can also be
described as being in one of two possible states. The
active shift group is described as being in the shift
phase when it is actively engaging/disengaging a
clutch combination. The 1-2/4-5 shift group control
the B1 and K1 clutches. The 2-3 shift group controls
the K2 and K3 clutches. The 3-4 shift group controls
the K3 and B2 clutches.
OPERATION
The transmission control is divided into the elec-
tronic and hydraulic transmission control functions.
While the electronic transmission control is responsi-
ble 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 hydrau-
lic transmission control, is provided by way of an oil
pump connected with the torque converter.
The Transmission Control Module (TCM) allows for
the precise adaptation of pressures to the correspond-
ing operating conditions and to the engine output
during the gearshift phase, resulting in a noticeable
improvement in shift quality. The engine speed limit
can be reached in the individual gears at full throttle
and kickdown. The shift range can be changed in the
forward gears while driving, but the TCM employs a
downshift safeguard to prevent over-revving the
engine. The system offers the additional advantage of
21 - 4 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

flexible adaptation to different vehicle and engine
variants.
EMERGENCY RUNNING FUNCTION
In order to ensure a safe driving state and to pre-
vent damage to the automatic transmission, the TCM
control module switches to limp-home mode in the
event of critical faults. A diagnostic trouble code
(DTC) assigned to the fault is stored in memory. All
solenoid and regulating valves are thus de-energized.
The net effect is:
²The last engaged gear remains engaged.
²The modulating pressure and shift pressures
rise to the maximum levels.
²The torque converter lockup clutch is deacti-
vated.
In order to preserve the operability of the vehicle
to some extent, the hydraulic control can be used to
engage 2nd gear or reverse using the following pro-
cedure:²Stop the vehicle.
²Move selector lever to ªPº.
²Switch off engine.
²Wait at least 10 seconds.
²Start engine.
²Move selector lever to D: 2nd gear.
²Move selector lever to R: Reverse gear.
The limp-home function remains active until the
DTC is rectified or the stored DTC is erased with the
appropriate scan tool. Sporadic faults can be reset
via ignition OFF/ON.
CLUTCH APPLICATION
Refer to CLUTCH APPLICATION for which shift
elements are applied in each gear position.
CLUTCH APPLICATION
GEAR RATIO B1 B2 B3 K1 K2 K3 F1 F2
1 3.59 X* X X* X X
2 2.19 X X X* X
3 1.41 X X X
4 1.00 X X X
5 0.83 X X X X*
N N/A X X
R 3.16 X* X X X
R - Limp
In1.93 X X X
* = The shift components required during coast.
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 5

FIRST GEAR POWERFLOW
Fig. 2 First Gear Powerflow
1 - TORQUE CONVERTER LOCK-UP CLUTCH 14 - CENTER PLANETARY CARRIER
2 - TORQUE CONVERTER TURBINE 15 - REAR PLANETARY CARRIER
3 - TORQUE CONVERTER IMPELLER 16 - TORQUE CONVERTER STATOR
4 - HOLDING CLUTCH B1 17 - FRONT PLANETARY PINION GEARS
5 - HOLDING CLUTCH B3 18 - CENTER PLANETARY PINION GEARS
6 - HOLDING CLUTCH B2 19 - REAR PLANETARY PINION GEARS
7 - DRIVING CLUTCH K1 20 - FREEWHEELING CLUTCH F1
8 - FRONT PLANETARY ANNULUS GEAR 21 - FRONT PLANETARY SUN GEAR
9 - DRIVING CLUTCH K2 22 - CENTER PLANETARY SUN GEAR
10 - CENTER PLANETARY ANNULUS GEAR 23 - REAR PLANETARY SUN GEAR
11 - REAR PLANETARY ANNULUS GEAR 24 - FREEWHEELING CLUTCH F2
12 - DRIVING CLUTCH K3 25 - INPUT SHAFT
13 - FRONT PLANETARY CARRIER 26 - OUTPUT SHAFT
A - ENGINE SPEED D - SECOND GEAR RATIO
B - TRANSMISSION INPUT SPEED E - THIRD GEAR RATIO
C - FIRST GEAR RATIO F - FIXED PARTS
21 - 6 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA