2005 MERCEDES-BENZ SPRINTER ESP

The B1 (7) pressure acting on the end face of the
shift pressure shift valve (3) is replaced by the work-
ing pressure (p-A). The rising shift pressure (p-S) at
clutch K1 (6) acts on the annular face of the overlap
regulating valve (2) and reduces the overlap pressure
regulated by the overlap regulating valve (2). When a
corresponding pressure level is reached at the hold-
ing pressure shift valve (4), this valve switches over.Second Gear Engaged
After the gearchange is complete, the pressure on
the end face of the command valve (5) (Fig. 16) is
reduced via the 1-2 and 4-5 shift solenoid valve (1),
and the command valve (5) is pushed back to its
basic position. Via the holding pressure shift valve
(4) the working pressure (p-A) now passes via the
command valve (5) to clutch K1 (6). The multiple-disc
holding clutch B1 (7) is deactivated (unpressurized).
The spring of the shift pressure shift valve (3) pushes
the valve back to its basic position.
Fig. 16 Second Gear Engaged
1 - 1-2/4-5 SHIFT SOLENOID 5 - 1-2/4-5 COMMAND VALVE
2 - 1-2/4-5 OVERLAP VALVE 6 - DRIVING CLUTCH K1
3 - 1-2/4-5 SHIFT PRESSURE SHIFT VALVE 7 - HOLDING CLUTCH B1
4 - 1-2/4-5 HOLDING PRESSURE SHIFT VALVE
VAAUTOMATIC TRANSMISSION - NAG1 21 - 19
AUTOMATIC TRANSMISSION - NAG1 (Continued)

DIAGNOSIS AND TESTING - AUTOMATIC TRANSMISSION
CONDITION POSSIBLE CAUSES CORRECTION
MAXIMUM SPEED 30 km/h 1. Speed Control 30 Actuated. 1. Instruct Customer.
ENGINE DIES WHEN
TRANSMISSION IS
SHIFTED INTO GEAR,
ALSO NOISES IN N
AND/OR P1. PWM Valve Blocked. 1. Replace Valve.
2. Torque Converter Lock Up Control
Valve Locked.2. Enable Movement of Valve,
Remove Particle.
LEVER IN9P9POSITION
BLOCKED (BRAKE
ACTIVATED)1. No Vacuum Brake Booster After
Long Immobilization, Brake Pedal
Not Fully Applied/Hard Pedal.1. Check Vacuum/ Tightness of
Brake Booster.
2. No Stoplamp Switch Signal (no
DTC IN ECM).2. Check Contact to Stoplamp
Switch. Replace Switch if
Necessary.
GRUMBLING, DRONING,
JERKING WHEN TCC IS
ENGAGED1. Slip Speed TCC to Low. 1. Switch Off Torque Converter
Lock Up Using DRBT.If
Complaint Is Not Reproduced
Afterwards, Replace PWM
Valve, Set Adaption Values to
Zero.
HOWLING, HUMMING
ABOVE 4000 RPM IN
EACH GEAR1. Oil Filter Blocked. 1. Replace Oil Filter.
2. Oil Pump. 2. Replace Oil Pump.
WHINING, SINGING 1. Gear Set Noises in 1st, 2nd, 5th
Gear.1. Replace Transmission..
2. Intermediate Bearing Of The Drive
Shaft At 0 km/h, Only When Cold.2. Replace Intermediate
Bearing of the Drive Shaft.
9CLACK9NOISE FROM
CENTER SHIFT AREA
WHEN STOPPING OR
STARTING1. Park Lock Solenoid. 1. Replace Shift Lever
Assembly.
CRACKING NOISE WHEN
LOAD CYCLE1. Stick - Slip Between Joint Flange
and Collar Nut.1. Install Zinc Coated Collar Nut
Together With Washer.
CHATTERING IN CENTER
CONSOLE SHIFT WHILE
ACCELERATING1. Bushing Shift Shaft Has Too Much
Clearance.1. Replace Shifter Lever and
Cover Plate.
HARD 2-3 UPSHIFT WHEN
STEPPING OFF THE
ACCELERATOR PEDAL1. Response Characteristic Control
Loop.1. Install K2 Disc Spring.
UPSHIFT 2-3, 3-4
SLIPPING1. Spring of Regulating Valve
Pressure control Valve Broken.1. Replace Spring.
HARD 2-1 DOWNSHIFT
WHEN COMING TO A
STOP1. Transmission (2-1 downshift) Not
Adapted.1. Re-adapt Transmission.
2. TCM Software Data. 2. Flash TCM.
3. Free Wheeling Clutch F1
Defective.Replace Free Wheeling Clutch
F1.
21 - 24 AUTOMATIC TRANSMISSION - NAG1VA
AUTOMATIC TRANSMISSION - NAG1 (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
HARD 3-2 DOWNSHIFT
WHEN DECELERATION
EVEN AFTER
READAPTION1. K3 Idles. 1. Install TCM And/Or
Electrohydraulic Control Unit.
NO RESP. DELAYED
UPSHIFT, NO DTC1. Different Tire Sizes Are Mounted
On The Front Axle.1. Mount Uniform Tire Sizes On
The Front Axle.
NO UPSHIFT 3-4, 4-5
AFTER FAST OFF
(ACCELERATOR)1. Upshift Prevention To Realize
Dynamical Drivestyle.1. Instruct Customer.
NO UPSHIFT OF 1ST
GEAR BELOW 5000 RPM1. Gear Recognition Switch. 1. Replace Gear Recognition
Switch.
NO UPSHIFT INTO 5TH
GEAR WHEN FULL
THROTTLE OR KICK
DOWN ACTIVATION1. The Upshift 4-5 At Full Throttle or
Kick Down Never Occurs Until
Reaching Cut Off Speed. Under
These Conditions, The High
Powered Vehicle Will Never Shift
Into 5th Gear Below 250 km/h.1. Instruct Customer.
NO KICK DOWN
SHIFTING1. Accelerator Pedal Value < 95%. 1. Check Engine Control. Adjust
As Necessary.
Engine Turns Up While 2-3
Upshift and/or Hard 3-2
Downshift1. Oil Level Too Low. 1. Check Oil Level. Add if
Necessary.
2. Oil Filter Not Installed. 2. Install Oil Filter.
3. Free Wheeling Clutch F2
Defective.3. Replace Free Wheeling
Clutch F2, Hollow Shaft, and
Rear Sun Gear/Inner Disc
Carrier K3.
GRABBING 2-3 COASTING
UPSHIFT AND/OR BRAKE
DOWNSHIFT1. Oil Level Too Low. 1. Check Oil Level. Add if
Necessary.
2. Oil Filter Not Installed. 2. Install Oil Filter.
3. Control shift or Command Valve
Blocked.3. Check Each Slide Valve For
Base Position and Ease Of
Movement, Remove Particle.
4. K3 Disc Burnt, Hot Spots or
Rubbed Down.4. Replace Inner and Outer
Disc Carrier K3 And Control
Valve.
VAAUTOMATIC TRANSMISSION - NAG1 21 - 25
AUTOMATIC TRANSMISSION - NAG1 (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
DELAYED ENGAGEMENT,
NO TRANSFER OF
POWER IN R AND/OR D,
ALSO AT TIMES1. Oil Level Too Low. 1. Check Oil Level. Add if
Necessary.
2. Recognition Switch - Selector
Lever Position.2. Replace Recognition Switch
Only When Intermediate
Position or Fault is Indicated.
3. Oil Filter Not Installed. 3. Install Oil Filter.
4. AEV, Delayed Pressure Build Up
On Piston B2/B3.4. Install New Shifting
Procedure (TCM,
electrohydraulic control unit or
repair set).
5. Wrong Combination TCM/
Electrohydraulic Control Unit.5. Check Combination
TCM/Electrohydraulic Control
Unit. Replace TCM Resp.
Electrohydraulic Control Unit, if
necessary.
NO UPSHIFT OF 1ST
GEAR AT TIMES1. Connector Ballast Unit. Output
Speed Sensor Loose, Incorrectly
Contacted.1. Check Connectors, Replace
Output Speed sensor If
Necessary.
2. Output Speed Sensor Defective 2. Replace Output Speed
Sensor.
LEAKAGE AT THE AREA
OF THE ELECTRICAL
PLUG TO THE
CONDUCTOR PLATE1. Deformation O-Rings. 1. Replace O-Rings.
2. Deformation Adapter. 2.Replace Adaptor.
3. The Conductor Plate Is Not Fitted
Surface To Surface On The Valve
Body In One Corner, The Plug Is Not
Centered In The Socket And The
O-ring Will Not Seal.3. Remove Nose Of Conductor
Plate.
4. Contacting At The Conductor Plate
Leaky. Oil In Harness, Sometimes In
The Control Module.4. Replace Conductor Plate.
LEAKAGE AT THE AREA
OF BELL HOUSING/
TORQUE CONVERTER1. Bolts (Torx M6) Outer Disc Carrier
B1.1. Clean Thread and Install the
Bolts Using Sealer.
OIL LEAKS 1. 6 Lower Bolts (TorxM8) Converter
Housing.1. Clean Thread and Install the
Bolts Using Sealer.
2. Oil Drain Plug Converter Loose
Resp. No Seal Ring Installed.2. Install Drain Plug Correctly.
3. Weld Seam Of Torque Converter
Leaky.3. Replace Torque Converter.
4. Radial Sealing Ring Oil Pump
Defective.4. Replace Sealing Ring.
5. O-Ring Oil Pump Defective Or Not
Installed.5. Install O-Ring.
6. Bushing Of Oil Pump Loose,
caused By Missing Fit Bolt At
Transmission/Engine Flange.6. Install Fit Bolt If Necessary.
21 - 26 AUTOMATIC TRANSMISSION - NAG1VA
AUTOMATIC TRANSMISSION - NAG1 (Continued)

Shift Pressure (p-S)
The shift pressure is determined by the shift pres-
sure regulating solenoid valve and the shift pressure
regulating valve. The shift pressure:
²Regulates the pressure in the activating shift
element during the shift phase.
²Determines together with the modulating pres-
sure the pressure reduction at the deactivating shift
element as regulated by the overlap regulating valve.
²Initializes 2nd gear in limp-home mode.
Modulating Pressure (p-Mod)
The modulating pressure influences the size of the
working pressure and determines together with the
shift pressure the pressure regulated at the overlap
regulating valve. The modulating pressure is regu-
lated at the modulating pressure regulating solenoid
valve, which is under regulating valve pressure. The
modulating pressure is variable and relative to the
engine load.Regulating Valve Pressure (p-RV)
The regulating valve pressure is regulated at the
regulating valve pressure regulating valve in relation
to the working pressure (p-A) up to a maximum pres-
sure of 8 bar (116 psi). It supplies the modulating
pressure regulating solenoid valve, the shift pressure
regulating solenoid valve and the shift valve pressure
regulating valve.
Shift Valve Pressure (p-SV)
The shift valve pressure (p-SV) is derived from the
regulating valve pressure (p-RV), is regulated at the
shift valve pressure regulating valve and is then
present at the:
²1-2 and 4-5 shift solenoid valve.
²3-4 shift solenoid valve.
²2-3 shift solenoid valve.
²Torque converter lockup solenoid valve.
²3-4 and 2-3 shift pressure shift valve.
The shift valve pressure (p-SV) controls the com-
mand valves via the upshift/downshift solenoid
valves.
Overlap Pressure (p-š)
The overlap pressure controls the shift component
pressure reduction during a shift phase. The pres-
sure in a shift element as it disengages is controlled
during the shift phase depending on engine load
(modulating pressure) and the pressure in the shift
element as it engages. The adjusted pressure is
inversely proportional to the transmission capability
of the shift element being engaged (controlled over-
lap).
Working Pressure Regulating Valve (Operating Pressure)
The working pressure regulating valve (Fig. 89) is
located in the valve housing of the shift plate. It reg-
ulates the primary pressure of the hydraulic system.
Torque Converter Lockup Clutch Regulating Valve
The torque converter lock-up clutch regulating
valve (Fig. 90) is located in the valve housing of the
electrohydraulic control module. The valve is respon-
sible for the hydraulic control of the torque converter
lockup clutch and distribution of the lubricating oil.
Overlap Regulating Valve
Each shift group is assigned one overlap regulating
valve (Fig. 91). The 1-2 / 4-5 overlap regulating valve
is installed in the shift valve housing; the 2-3 and 3-4
overlap regulating valves are installed in the valve
housing. The overlap regulating valve regulates the
pressure reduction during a shift phase.
Fig. 88 Electrical Control Unit
1 - N3 SPEED SENSOR
2 - PLUG CONNECTOR
3 - MODULATING PRESSURE REGULATING SOLENOID
4 - SHIFT PRESSURE REGULATING SOLENOID
5 - 1-2/4-5 SHIFT SOLENOID
6 - 3-4 SHIFT SOLENOID
7 - ELECTRICAL CONTROL UNIT
8 - TRANSMISSION TEMPERATURE SENSOR
9 - STARTER INTERLOCK CONTACT
10 - 2-3 SHIFT SOLENOID
11 - TORQUE CONVERTER LOCK-UP SOLENOID
12 - N2 SPEED SENSOR
VAAUTOMATIC TRANSMISSION - NAG1 21 - 83
ELECTROHYDRAULIC UNIT (Continued)

Overlap Regulating Valve
During the shift phase the pressure (Fig. 102) in
the deactivating shift actuator is regulated in rela-
tion to the engine load (modulating pressure) and the
pressure in the activating actuator. The regulated
pressure is inversely proportional to the transfer
capacity of the activating shift actuator (regulated
overlap).
Command Valve
When the end face is unpressurized (stationary
phase), the working pressure is directed to the actu-
ated shift element. If the end face of the commandvalve (Fig. 103) is subjected to the shift valve pres-
sure (p-SV) (shift phase), then the shift pressure is
switched to the activating element and the overlap
pressure is switched to the deactivating element.
Shift Valve Holding Pressure
The holding pressure shift valve (Fig. 104) is actu-
ated by the pressures present at the end face in the
actuators and a spring. It assigns the working pres-
sure to the actuator with the higher pressure (taking
into account the spring force and the effective surface
area). The other element of the shift group is then
unpressurized. The valve switches over only during
the shift phase and only at a certain pressure ratio
between the overlap pressure (p-š) and the shift
pressure (p-S).
Shift Pressure Shift Valve
When the multiple-disc brake B1 (3) is activated,
the working pressure (pa) is applied to the end face
of the 1-2 / 4-5 shift pressure shift valve (4) (Fig. 105)
via the command valve (1). Its shift state is main-
tained during the shift phase by substituting the
shift element pressure acting on its end face (and
which is variable during the shift phase) with a cor-
responding constant pressure. When the multi-plate
clutch K1 (2) is activated, the end face of the shift
valve is unpressurized during the stationary and
shift phases, so the shift state is maintained during
the shift phase in this case too.
Fig. 103 Command Valve
1 - HOLDING CLUTCH B1
2 - DRIVING CLUTCH K13 - 1-2/4-5 COMMAND VALVE
Fig. 102 Overlap Regulating Valve
1 - OVERLAP REGULATING VALVE
2 - ANNULAR SURFACE ON OVERLAP REGULATING VALVE
VAAUTOMATIC TRANSMISSION - NAG1 21 - 89
ELECTROHYDRAULIC UNIT (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)

INSTRUMENT PANEL
ASSEMBLY
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, SEAT BELT TENSIONER, OR INSTRU-
MENT PANEL COMPONENT DIAGNOSIS OR SER-
VICE. DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE, THEN WAIT TWO
MINUTES FOR THE AIRBAG SYSTEM CAPACITOR
TO DISCHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
²WHEN REMOVING A DEPLOYED AIRBAG, RUB-
BER GLOVES, EYE PROTECTION, AND A LONG-
SLEEVED SHIRT SHOULD BE WORN. THERE MAY
BE DEPOSITS ON THE AIRBAG UNIT AND OTHER
INTERIOR SURFACES. IN LARGE DOSES, THESE
DEPOSITS MAY CAUSE IRRITATION TO THE SKIN
AND EYES.
²USE EXTREME CARE TO PREVENT ANY FOR-
EIGN MATERIAL FROM ENTERING THE PASSEN-
GER AIRBAG, OR BECOMING ENTRAPPED
BETWEEN THE PASSENGER AIRBAG CUSHION
AND THE PASSENGER AIRBAG DOOR. FAILURE TO
OBSERVE THIS WARNING COULD RESULT IN
OCCUPANT INJURIES UPON AIRBAG DEPLOY-
MENT.
²THE PASSENGER AIRBAG DOOR MUST
NEVER BE PAINTED. REPLACEMENT PASSENGER
AIRBAGS ARE SERVICED WITH DOORS IN THE
ORIGINAL COLORS. PAINT MAY CHANGE THE WAY
IN WHICH THE MATERIAL OF THE AIRBAG DOOR
RESPONDS TO AN AIRBAG DEPLOYMENT. FAIL-
URE TO OBSERVE THIS WARNING COULD RESULT
IN OCCUPANT INJURIES UPON AIRBAG DEPLOY-
MENT.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove radio. (Refer to 8 - ELECTRICAL/AU-
DIO/RADIO - REMOVAL)
(3) Remove glove compartment. (Refer to 23 -
BODY/INSTRUMENT PANEL/GLOVE BOX -
REMOVAL)
(4) Remove cup holder. (Refer to 23 - BODY/IN-
STRUMENT PANEL/CUP HOLDER - REMOVAL)
(5) Remove instrument cluster. (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - REMOVAL)(6) Remove passenger airbag. (Refer to 8 - ELEC-
TRICAL/RESTRAINTS/PASSENGER AIRBAG -
REMOVAL)
(7) Remove right and left speakers. (Refer to 8 -
ELECTRICAL/AUDIO/SPEAKER - REMOVAL)
(8) Remove center bezel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/INSTRUMENT PANEL CEN-
TER BEZEL - REMOVAL)
(9) Remove air conditioning push-button control
module. (Fig. 7)
(10) Twist cover lock 1/4 turn and remove Power
Distribution Center (PDC) cover. (Fig. 8)
Fig. 7 HVAC CONTROL MODULE
1 - CONTROL CABLES
2 - ELECTRICAL CONNECTORS
3 - MODULE
4 - SCREWS
Fig. 8 POWER DISTRIBUTION CENTER COVER
1 - COVER LOCK
2 - COVER
VAINSTRUMENT PANEL 23 - 57