2005 MERCEDES-BENZ SPRINTER low oil pressure

DIAGNOSIS AND TESTING - AIR IN FUEL
SYSTEM
Air will enter the fuel system whenever fuel supply
lines, separator filters, injection pump, high-pressure
lines or injectors are removed or disconnected. Air
trapped in the fuel system can result in hard start-
ing, a rough running engine, engine misfire, low
power, excessive smoke and fuel knock.
Inspect the fuel system from the fuel tank to the
injectors for loose connections (Refer to 14 - FUEL
SYSTEM - WARNING). Leaking fuel is an indicator
of loose connections or defective seals. Air can also
enter the fuel system between the fuel tank and the
fuel pump. Inspect the fuel tank and fuel lines for
damage that might allow air into the system.
With the DRBIIItconnected to the vehicle, select
Engine and the select Sensor Display. Page down to
view Fuel Pressure Set Point and Actual Fuel Pres-
sure. Start the engine and observe the Fuel Pressure
Set Point and the Actual Fuel Pressure. If the Actual
Fuel Pressure Oscillates above and below the Fuel
Pressure Set Point in a regular cycle, perform the
Fuel System Air Purge procedure (Refer to 14 -
FUEL SYSTEM - STANDARD PROCEDURE).
If the Actual Fuel Pressure gradually drops below
the Fuel Pressure Set Point then spikes well above
the Fuel Pressure Set Point, replace the fuel pres-
sure solenoid (Refer to 14 - FUEL SYSTEM/FUEL
INJECTION/FUEL PRESSURE SOLENOID -
REMOVAL), then perform the Fuel System Air Purgeprocedure (Refer to 14 - FUEL SYSTEM - STAN-
DARD PROCEDURE).
STANDARD PROCEDURE
STANDARD PROCEDURES - CLEANING FUEL
SYSTEM COMPONENTS
CAUTION: Cleanliness cannot be overemphasized
when handling or replacing diesel fuel system com-
ponents. This especially includes the fuel injectors,
high-pressure fuel lines, fuel rail, and fuel injection
pump. Very tight tolerances are used with these
parts. Dirt contamination could cause rapid part
wear and possible plugging of fuel injector nozzle
tip holes. This in turn could lead to possible engine
misfire. Always wash/clean any fuel system compo-
nent thoroughly before disassembly and then air
dry. DO NOT wire brush injector nozzles when
cleaning. Cap or cover any open part after disas-
sembly. Before assembly, examine each part for
dirt, grease or other contaminants and clean if nec-
essary. When installing new parts, lubricate them
with clean engine oil or clean diesel fuel only.
STANDARD PROCEDURE - DISCONNECTING
AND CONNECTING FUEL LINES
NOTE: Capture and store any fuel spillage in appro-
priately marked containers.
(1) Disconnect negative battery cable.
(2) Push release arm to release position A, as far
as the stop (arrow) (Fig. 2).
(3) Disconnect fuel line.
(4) Immediately return the release arm back to the
assembly position, as far as the stop (Fig. 2).
The release arm must not be left in the release
position for a long time. Connectors left in the
release position for lengthy periods may leak and
must be replaced.
(5) Insert connector into connection in assembly
position (B) (Fig. 2).
(6) Ensure that the connectors are firmly seated
and free of leaks (Fig. 2).
STANDARD PROCEDURES - DRAINING WATER
FROM FUEL FILTER
Refer to Fuel Filter/Water Separator removal/in-
stallation for procedures (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/FUEL FILTER / WATER
SEPARATOR - REMOVAL).
Fig. 1 Typical Test for Leaks with Cardboard
1 - HIGH-PRESSURE LINE
2 - CARDBOARD
3 - FITTING
14 - 2 FUEL SYSTEMVA
FUEL SYSTEM (Continued)

SPECIAL TOOLS
FUEL SYSTEM
SPECIAL TOOL CROSS REFERENCE CHART
MB
TOOL #MILLER
TOOL #DESCRIPTION
N/A 5069-2 FUEL GAUGE
N/A 6856 SPANNER WRENCH
N/A 9068 FUEL GAUGE ADAPTER
N/A 9285 FUEL LINE WRENCH
FUEL DRAIN TUBES
DIAGNOSIS AND TESTING - FUEL SUPPLY
RESTRICTIONS
LOW-PRESSURE LINES
Fuel supply line restrictions can cause starting
problems and prevent engine from accelerating. The
starting problems include; low power and/or white
fog like exhaust.
Test all fuel supply lines for restrictions or block-
age. Flush or replace as necessary.
HIGH-PRESSURE LINES
CAUTION: High pressure lines cannot contact each
other or other components. Do not attempt to weld
high-pressure fuel lines or to repair lines that are
damaged. High pressure lines must be replaced at
each disassembly. Use only recommended lines
when replacement of high-pressure fuel line is nec-
essary.
Restricted (kinked or bent) high-pressure lines can
cause starting problems, poor engine performance,
engine mis-fire and white smoke from exhaust (Refer
to 14 - FUEL SYSTEM - WARNING).
FUEL FILTER
DESCRIPTION
In order to assure trouble free operation with win-
ter grade diesel fuel, a preheater valve is located
with in the fuel filter. Depending on the temperature
of the heated return flow fuel, fuel flows back
through the preheating valve into the fuel filter to
heat up or flows through the cooling coils directly
back into the fuel tank.
OPERATION
PRE - HEATING Up to 30ÉC (86ÉF), the thermo
bimetal plate of the preheater, shuts off the return
fuel flow port to the fuel tank. The fuel from the rail
flows into the fuel filter to be warmed. If there is air
in the system, a ball seals off a port and the air is
directed to the fuel tank.
NON PRE - HEATING From above 30ÉC (86ÉF) the
thermo bimetal plate of the preheater, shuts off the
port to the fuel filter and fuel from the rail flows
directly into the return flow line to the fuel tank.
REMOVAL
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
(1) Disconnect negative battery cable.
(2) Separate the fuel outlet line connector on the
fuel filter (Refer to 14 - FUEL SYSTEM - STAN-
DARD PROCEDURE). (Fig. 1)
(3) Slacken the hose clamp on the fuel inlet line
and detach fuel line (Fig. 1).
SPANNER WRENCH-6856
FUEL LINE WRENCH-9285
VAFUEL DELIVERY 14 - 5
FUEL DELIVERY (Continued)

(1) Loosely position fuel rail into position on cylin-
der head.
(2) Position and loosely install fuel return line
from fuel filter, with new seals to rail (Fig. 7).
(3) Position fuel rail to cylinder head, feed in high
pressure line with new seals (Fig. 7).
CAUTION: Inspect sealing cones at the lines.
Replace as necessary. Ensure that all fuel pressure
lines are exactly located in original position.
(4) Hand start all injector lines (Fig. 7).
CAUTION: When tightening fuel injection line union
nuts, counter hold with a wrench at the thread con-
nection. ON NO ACCOUNT exceed the tightening
torque at any time.
(5) Tighten fuel rail bolts to 14 N´m (124 lbs.in.)
(Fig. 7).
(6) Tighten nut of pressure line to rail/injector to
22N´m (194 lbs.in.).
(7) Tighten nut of pressure line to high pressure
pump/rail to 22N´m (194 lbs.in.).(8) Tighten banjo bolt of fuel return line to fuel
rail to 20N´m (177 lbs.in.).
(9) Install fuel temperature sensor.
(10) Install front engine support lift.
(11) Install thermostat housing.
(12) Reconnect engine harness electrical connec-
tors (Fig. 7).
(13) Refill cooling system.
(14) Connect negative battery cable.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH FAN. DO NOT PUT YOUR
HANDS NEAR PULLEYS, BELTS OR FAN. DO NOT
WEAR LOOSE CLOTHING.
(15) Start engine and inspect for leaks (Refer to 14
- FUEL SYSTEM - WARNING).
FUEL TANK
DESCRIPTION
The plastic fuel tank is mounted to the frame rails
under the left/center side of the vehicle. The fuel
tank contains a serviceable fuel tank module (Fig. 8)
and fuel level sending unit. The tank is also
equipped with 2 fuel lines: a fuel supply line to the
fuel pump, and a separate fuel return line. A section
of the fuel return line is coiled (Fig. 8) at the rear
section of the tank. This coiled section is used to help
drop the temperature of fuel returning to the tank.
A fuel tank mounted, electric fuel pump is not used
with diesel powered models. Refer to Fuel Tank Mod-
ule for additional information.
REMOVAL
(1) Drain diesel fuel from tank using an approved
diesel fuel draining station.
(2) Disconnect fuel fill and vent lines (Fig. 8) from
body.
(3) Raise and support vehicle.
(4) Support tank with a hydraulic jack.
(5) Remove 2 fuel tank strap nuts and position
straps towards left side of vehicle.
(6) Carefully lower tank a few inches and discon-
nect electrical connector at top of fuel tank module.
(7) Disconnect fuel supply line at tank.
(8) Disconnect fuel return line at tank.
(9) Continue to carefully lower tank for removal.
(10) If fuel tank module is to be removed, thor-
oughly clean area at top of fuel tank around module.
(11) If fuel tank is to be replaced, remove fuel tank
module from tank. Refer to Fuel Tank Module
Removal/Installation procedures.
Fig. 7 FUEL PRESSURE SOLENOID
1 - INJECTION LINES
2 - FUEL RAIL
3 - FUEL RETURN LINE
4 - FUEL PRESSURE SOLENOID
5 - OIL LINE
6 - SEALS
7 - FUEL RETURN LINE AT COOLER
8 - HIGH PRESSURE FUEL LINE TO FUEL RAIL
9 - FUEL LINE BRACKET
10 - FUEL PRESSURE SENSOR
14 - 12 FUEL DELIVERYVA
FUEL RAIL (Continued)

NOTE: Always replace the seals that seal off the
injectors at the cylinder head to the combustion
chamber and replace the retaining screws.
REMOVAL
WARNING: HIGH-PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 1600BAR (23,200 PSI).
USE EXTREME CAUTION WHEN INSPECTING FOR
HIGH-PRESSURE FUEL LEAKS. FUEL UNDER THIS
AMOUNT OF PRESSURE CAN PENETRATE SKIN
CAUSING PERSONAL INJURY OR DEATH. INSPECT
FOR HIGH-PRESSURE LEAKS WITH A SHEET OF
CARD BOARD. WEAR SAFETY GOGGLES AND
ADEQUATE PROTECTIVE CLOTHING WHEN SER-
VICING FUEL SYSTEM.
WARNING: NO SPARKS, OPEN FLAMES OR SMOK-
ING. RISK OF POISONING FROM INHALING AND
SWALLOWING FUEL. RISK OF INJURY TO EYES
AND SKIN FROM CONTACT WITH FUEL. POUR
FUELS ONLY INTO SUITABLE AND APPROPRI-
ATELY MARKED CONTAINERS. WEAR PROTECTIVE
CLOTHING.
NOTE: The engine must be lowered in the vehicle to
remove the fourth and fifth cylinders fuel injectors.
(1) Disconnect negative battery cable.
(2) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
(3) Raise and suitably support the vehicle.
(4) Remove lower radiator deflector plate.
(5) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(6) Remove turbocharger down pipe assembly.
(7) Remove oil dipstick tube retaining bolt and pull
tube from oil pan.
(8) Lower vehicle.
(9) Remove upper radiator hose.
(10) Remove air cleaner box assembly and hoses.
(11) Remove charge air cooler inlet hose.
(12) Remove charge air cooler to turbocharger inlet
adaptor.
(13) Remove turbocharger to right engine mount
bracket.
(14) Disconnect steering coupler at gear box (RHD
Only).
(15) Remove battery (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM/BATTERY - REMOVAL).
(16) Unclip PDC from battery tray and set aside.(17) Remove battery tray (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/TRAY - REMOVAL).
(18) Remove power steering reservoir (Refer to 19 -
STEERING/PUMP/RESERVOIR - REMOVAL).
(19) Remove charger air cooler outlet hose.
(20) Remove intake manifold to left engine mount
bracket.
(21) Evacuate air conditioning system (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(22) Disconnect air conditioning suction / discharge
lines at A/C compressor.
(23) Disconnect pedal position sensor electrical
connector.
(24) Unplug injector electrical connectors.
(25) Remove fuel / water separator to intake man-
ifold retaining bolts.
(26) Support engine with hoist.
(27) Remove engine mount through bolts.
(28) Remove right engine mount sill plate.
NOTE: Counterhold injection lines with wrench
socket at threaded connections of injectors.
(29) Disconnect fuel injector high pressure line.
(30) Remove fuel injector retaining bolt and ten-
sion claw.
(31) Suitably lower engine to gain fuel injector
access and remove injector.
NOTE: If injectors are tight, remove with extraction
claw in place of tensioning claw. If extraction claw
contacts cylinder head cover, remove cylinder head
cover. If necessary, remove injectors with threaded
adaptor and discard injector.
(32) Remove injectors (Fig. 10).
(33) Clean injectors and recesses (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION/FUEL INJEC-
TOR - STANDARD PROCEDURE).
INSTALLATION
WARNING: HIGH-PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 1600BAR (23,200 PSI).
USE EXTREME CAUTION WHEN INSPECTING FOR
HIGH-PRESSURE FUEL LEAKS. FUEL UNDER THIS
AMOUNT OF PRESSURE CAN PENETRATE SKIN
CAUSING PERSONAL INJURY OR DEATH. INSPECT
FOR HIGH-PRESSURE LEAKS WITH A SHEET OF
CARD BOARD. WEAR SAFETY GOGGLES AND
ADEQUATE PROTECTIVE CLOTHING WHEN SER-
VICING FUEL SYSTEM.
VAFUEL INJECTION 14 - 23
FUEL INJECTOR (Continued)

(15) Install battery tray(Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/TRAY - INSTALLATION).
(16) Connect PDC to battery tray.
(17) Install battery (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM/BATTERY - INSTALLATION).
(18) Connect steering coupler at gear box (RHD
Only).
(19) Install turbocharger to right engine mount
bracket (Refer to 11 - EXHAUST SYSTEM/TURBO-
CHARGER SYSTEM - INSTALLATION).
(20) Install charge air cooler to turbocharger inlet
adaptor (Refer to 11 - EXHAUST SYSTEM/CHARGE
AIR COOLER AND PLUMBING - INSTALLATION) .
(21) Install charger air cooler inlet hose (Refer to
11 - EXHAUST SYSTEM/CHARGE AIR COOLER
AND PLUMBING - INSTALLATION).
(22) Install air cleaner box assembly and hoses.
(23) Install upper radiator hose.
(24) Raise vehicle.
(25) Install dipstick tube into oil pan and tighten
retaining bolt.
(26) Install turbocharger down pipe assembly.
(27) Close cooling system drain.
(28) Install lower radiator deflector plate.
(29) Lower vehicle.
(30) Connect negative battery cable.
(31) Install engine cover (Refer to 9 - ENGINE -
INSTALLATION)..
(32) Fill cooling system with the correct mixture to
the proper level (Refer to 7 - COOLING/ENGINE/
COOLANT - STANDARD PROCEDURE).
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT PUT YOUR
HANDS NEAR PULLEYS, BELTS OR FAN. DO NOT
WEAR LOOSE CLOTHING.
(33) Start engine and inspect for leaks.
(34) Recharge air conditioning system.
FUEL PRESSURE SENSOR
DESCRIPTION
DESCRIPTION
The fuel pressure sensor provides the current low
pressure (the pressure that exist at the inlet of the
high pressure injection pump) fuel pressure to the
ECM (Fig. 11).
The fuel pressure when the engine is idling is
approximately 36 psi (2.5 Bar). The fuel pressure
while driving is 50±58 psi (3.5 - 4.0Bar).
DESCRIPTION
The fuel rail pressure sensor provides the current
fuel rail pressure to the ECM.
OPERATION
OPERATION
A diaphragm and an electric resistance meter are
integrated in the fuel pressure sensor. The non-con-
stant fuel system pressure from the low pressure fuel
pump influences the position of the diaphragm which
in turn alters it's electrical resistance. This resis-
tance is analyzed by the ECM. The ECM then actu-
ates the fuel rail pressure control valve until the
desired rail pressure value is obtained (Fig. 11).
OPERATION
The fuel rail pressure sensor measures the current
fuel rail pressure and sends a voltage signal to the
ECM. The ECM then actuates the fuel rail pressure
control valve solenoid until the desired rail pressure
is achieved.
Fig. 11 FUEL PRESSURE SENSOR
VAFUEL INJECTION 14 - 25
FUEL INJECTOR (Continued)

INSTALLATION
(1) (Refer to 14 - FUEL SYSTEM/FUEL INJEC-
TION - WARNING) Install the sealing ring on to the
sensor (Fig. 13).
(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. 13).
(3) Connect the wiring harness to the sensor.
(4) Install the mixing housing.
(5) Connect negative battery cable.
FUEL PRESSURE SOLENOID
DESCRIPTION
The fuel pressure solenoid is attached to the rear
of the fuel rail. The solenoid controls and maintains
the rail pressure constant along with a control cur-
rent transmitted by the engine control module (ECM)
(Fig. 14).
OPERATION
High pressure which is present in the fuel rail
flows to the ball seat of the solenoid (Fig. 15). 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 elec-
tronic control module (ECM) (Fig. 15). This magnetic
force equals a certain outlet cross section at the ball
seat of the solenoid. The rail pressure is altered as a
result of the quantity of fuel which flows off (Fig. 15).
The current fuel pressure is signaled by the fuel
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. 15). When driving, the fuel pressure
solenoid is constantly open (Fig. 15). When engine is
started, the fuel pressure solenoid is held closed by
magnetic force (Fig. 15). When driving, the pressure
of the fluid counteracts the magnetic force of the coil
and the slight spring force (Fig. 15).
Fig. 14 FUEL PRESSURE SOLENOID - TYPICAL
1 - INJECTION LINES
2 - FUEL RAIL
3 - FUEL RETURN LINE
4 - FUEL PRESSURE SOLENOID
5 - OIL LINE
6 - SEALS
7 - FUEL RETURN LINE AT COOLER
8 - HIGH PRESSURE FUEL LINE TO FUEL RAIL
9 - FUEL LINE BRACKET
10 - FUEL PRESSURE SENSOR
Fig. 15 FUEL PRESSURE SOLENOID OPERATION
1 - BALL SEAT
2 - SPRING FORCE
3 - MAGNETIC FORCE
4 - COIL
5 - FUEL PRESSURE SOLENOID
6 - HIGH PRESSURE FEED
VAFUEL INJECTION 14 - 27
FUEL PRESSURE SENSOR (Continued)

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.
(4)
Slowly turn the steering wheel lock-to-lock 20
times with the engine off while checking the fluid level.
NOTE: For vehicles with long return lines or oil
coolers turn wheel 40 times.
(5) Start the engine. With the engine idling main-
tain the fluid level.
(6) Lower the front wheels and let the engine idle
for two minutes.
(7) Turn the steering wheel in both direction and
verify power assist and quiet operation of the pump.
If the fluid is extremely foamy or milky looking,
allow the vehicle to stand a few minutes and repeat
the procedure.
CAUTION: Do not run a vehicle with foamy fluid for
an extended period. This may cause pump damage.
STANDARD PROCEDURE - FLUSHING POWER
STEERING SYSTEM
Flushing is required when the power steering/hy-
draulic booster system fluid has become contami-
nated. Contaminated fluid in the steering/booster
system can cause seal deterioration and affect steer-
ing gear/booster spool valve operation.
(1) Raise the front end of the vehicle off the
ground until the wheels are free to turn.
(2) Remove the return line from the pump.
NOTE: If vehicle is equipped with a hydraulic
booster remove both return lines from the pump.
(3) Plug the return line port/ports at the pump.
(4) Position the return line/lines into a large con-
tainer to catch the fluid.
(5) While an assistant is filling the pump reservoir
start the engine.
(6) With the engine running at idle turn the wheel
back and forth.
NOTE: Do not contact or hold the wheel against the
steering stops.
(7) Run a quart of fluid through the system then
stop the engine and install the return line/lines.
(8) Fill the system with fluid and perform Steering
Pump Initial Operation, (Refer to 19 - STEERING/
PUMP - STANDARD PROCEDURE).(9) Start the engine and run it for fifteen minutes
then stop the engine.
(10) Remove the return line/lines from the pump
and plug the pump port/ports.
(11) Pour fresh fluid into the reservoir and check
the draining fluid for contamination. If the fluid is
still contaminated, then flush the system again.
(12) Install the return line/lines and perform
Steering Pump Initial Operation, (Refer to 19 -
STEERING/PUMP - STANDARD PROCEDURE).
REMOVAL
(1) Remove the belt from the power steering pump.
(2) Siphon as much power steering fluid as possi-
ble out of the reservoir.
(3) Remove the high pressure power steering hose
at the pump (Fig. 1).
(4)
Remove the return hose from the pump (Fig. 1).
(5) Remove the bolts securing the power steering
pump to the engine (Fig. 1).
INSTALLATION
(1) Install the power steering pump to the engine
and tighten the bolts (Fig. 1). Tighten to 21 N´m (15
ft. lbs.).
(2) Replace all o-rings and hose clamps (Fig. 1).
(3) Install the return hose to the pump and tighten
the clamp (Fig. 1).
(4) Install the high pressure hose to the pump
(Fig. 1). Tighten to 38 N´m (28 ft. lbs.).
(5)
Fill the power steering fluid (Refer to 19 - STEER-
ING/PUMP/FLUID - STANDARD PROCEDURE).
Fig. 1 POWER STEERING PUMP
1 - PUMP MOUNTING BOLT
2 - CLAMP
3 - RETURN HOSE
4 - HIGH PRESSURE HOSE
5 - O-RING
6 - PUMP RESERVOIR
7 - PUMP
8 - PULLEY
9 - PULLEY BOLT
VAPUMP 19 - 13
PUMP (Continued)

OUTPUT SHAFT SEAL
REMOVAL............................125
INSTALLATION........................125
PARK LOCK CABLE
REMOVAL............................125
INSTALLATION........................126
PISTONS
DESCRIPTION........................128
OPERATION..........................128
PLANETARY GEARTRAIN
DESCRIPTION........................130
OPERATION..........................130
DISASSEMBLY........................131
ASSEMBLY...........................131
SHIFT MECHANISM
DESCRIPTION........................133
OPERATION..........................133
REMOVAL............................134
INSTALLATION........................135
SOLENOID
DESCRIPTION........................136OPERATION..........................138
TEMPERATURE SENSOR/PARK-NEUTRAL
CONTACT
DESCRIPTION
DESCRIPTION - PARK/NEUTRAL CONTACT . 139
DESCRIPTION - TRANSMISSION
TEMPERATURE SENSOR..............140
OPERATION
OPERATION - PARK/NEUTRAL CONTACT . . 140
OPERATION - TRANSMISSION
TEMPERATURE SENSOR..............141
TORQUE CONVERTER
DESCRIPTION........................141
OPERATION..........................143
REMOVAL............................146
INSTALLATION........................146
TORQUE CONVERTER HUB SEAL
REMOVAL............................147
INSTALLATION........................147
AUTOMATIC TRANSMISSION -
NAG1
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.
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.
²Increased service life and reliability.
²Lower maintenance costs.
TRANSMISSION IDENTIFICATION
The transmission name, NAG1, means New Auto-
matic Gearbox, generation 1.
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.
21 - 2 AUTOMATIC TRANSMISSION - NAG1VA