2006 MERCEDES-BENZ SPRINTER automatic transmission

First Gear Engaged
The TCM monitors the activation sequence via the
speed of the input shaft, which slows down as the
frictional connection in the multiple-disc holding
clutch increases. When the speed drops to the speci-
fied level, the TCM shuts off the power to the 3-4
shift solenoid valve (10) (Fig. 25). The spring cham-
ber of the shift valve B2 (9) is depressurized and
switches downwards. This connects the line to the
opposing face of the piston B2 (6) with the pressure
holding valve (11). The pressure on the opposing face
of the piston B2 (6) drops to a residual pressure.
The working pressure (p-A) is formed and travels
via the 2-3 holding pressure shift valve, the 2-3 com-
mand valve and the ball valve (16) to multi-plate
clutch K3 (4) and via the 3-4 command valve (13) to
the end face of the 3-4 shift pressure shift valve (14).
The 3-4 shift pressure shift valve (14) is moved
against the force of the spring towards the right. Atthe same time the 3-4 solenoid valve (10) is ener-
gized. This allows shift valve pressure (p-SV) to enter
the spring chamber of the shift valve B2 (9) and to
reach the end face of the 3-4 command valve (13).
The shift valve B2 (9) is held in the upper position
and the 3-4 command valve (13) switches towards the
right. At the end face of the 3-4 shift pressure shift
valve (14) the working pressure (p-A) is replaced by
shift valve pressure (p-SV).
The 3-4 command valve (13) moves to the left.
Working pressure (p-A) travels via the holding pres-
sure shift valve (12) and the 3-4 command valve (13)
to the piston of multiple-disc holding clutch B2 (5).
Fig. 25 First Gear Engaged
1 - HOLDING CLUTCH B1 11 - PRESSURE HOLDING VALVE
2 - DRIVING CLUTCH K1 12 - 3-4 HOLDING PRESSURE SHIFT VALVE
3 - HOLDING CLUTCH B3 13 - 3-4 COMMAND VALVE
4 - DRIVING CLUTCH K3 14 - 3-4 SHIFT PRESSURE SHIFT VALVE
5 - HOLDING CLUTCH B2 PISTON 15 - 3-4 OVERLAP REGULATING VALVE
6 - HOLDING CLUTCH B2 PISTON OPPOSING FACE 16 - BALL VALVE
7 - SHIFT PRESSURE REGULATING SOLENOID 17 - 1-2/4-5 COMMAND VALVE
8 - SHIFT PRESSURE REGULATING VALVE 18 - 1-2/4-5 COMMAND VALVE
9 - SHIFT VALVE B2 19 - BALL VALVE
10 - 3-4 SHIFT SOLENOID
21 - 38 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

DIAGNOSIS AND TESTING
AUTOMATIC TRANSMISSION
CAUTION: Before attempting any repair on a NAG1
automatic transmission, check for Diagnostic Trou-
ble Codes with the appropriate scan tool.
Transmission malfunctions may be caused by these
general conditions:
²Poor engine performance.
²Improper adjustments.
²Hydraulic malfunctions.
²Mechanical malfunctions.
²Electronic malfunctions.
²Transfer case performance (if equipped).
Diagnosis of these problems should always begin
by checking the easily accessible variables: fluid level
and condition, gearshift cable adjustment. Then per-
form a road test to determine if the problem has been
corrected or if more diagnosis is necessary.
PRELIMINARY
Two basic procedures are required. One procedure
for vehicles that are drivable and an alternate proce-
dure for disabled vehicles (will not back up or move
forward).
VEHICLE IS DRIVABLE
(1) Check for transmission fault codes using the
appropriate scan tool.
(2) Check fluid level and condition.
(3) Adjust gearshift cable if complaint was based
on delayed, erratic, or harsh shifts.
(4) Road test and note how transmission upshifts,
downshifts, and engages.
VEHICLE IS DISABLED
(1) Check fluid level and condition.(2) Check for broken or disconnected gearshift
cable.
(3) Check for cracked, leaking cooler lines, or loose
or missing pressure-port plugs.
(4) Raise and support vehicle on safety stands,
start engine, shift transmission into gear, and note
following:
(a) If propeller shaft turns but wheels do not,
problem is with differential or axle shafts.
(b) If propeller shaft does not turn and transmis-
sion is noisy, stop engine. Remove oil pan, and
check for debris. If pan is clear, remove transmis-
sion and check for damaged driveplate, converter,
oil pump, or input shaft.
(c) If propeller shaft does not turn and transmis-
sion is not noisy, perform hydraulic-pressure test to
determine if problem is hydraulic or mechanical.
ROAD TESTING
Before road testing, be sure the fluid level and con-
trol cable adjustments have been checked and
adjusted if necessary. Verify that all diagnostic trou-
ble codes have been resolved.
Observe engine performance during the road test.
A poorly tuned engine will not allow accurate analy-
sis of transmission operation.
Operate the transmission in all gear ranges. Check
for shift variations and engine flare which indicates
slippage. Note if shifts are harsh, spongy, delayed,
early, or if part throttle downshifts are sensitive.
Slippage indicated by engine flare, usually means
clutch, overrunning clutch, or line pressure problems.
A slipping clutch can often be determined by com-
paring which internal units are applied in the vari-
ous gear ranges. The Clutch Application chart
CLUTCH APPLICATION provides a basis for analyz-
ing road test results.
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 In 1.93 X X X
* = The shift components required during coast.
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 39

AUTOMATIC TRANSMISSION
CONDITION POSSIBLE CAUSES CORRECTION
MAXIMUM SPEED 30
km/h1. Speed Control 30 Actuated. 1. Instruct Customer.
ENGINE DIES WHEN
TRANSMISSION IS SHIFT-
ED INTO GEAR, ALSO
NOISES IN N AND/OR P1. PWM Valve Blocked. 1. Replace Valve.
2. Torque Converter Lock Up Con-
trol Valve Locked.2. Enable Movement of Valve,
Remove Particle.
LEVER IN ªPº POSITION
BLOCKED (BRAKE ACTI-
VATED)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 Nec-
essary.
GRUMBLING, DRONING,
JERKING WHEN TCC IS
ENGAGED1. Slip Speed TCC to Low. 1. Switch Off Torque Converter
Lock Up Using DRBT. If Com-
plaint Is Not Reproduced After-
wards, 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 Bear-
ing of the Drive Shaft.
9CLACKº NOISE FROM
CENTER SHIFT AREA
WHEN STOPPING OR
STARTING1. Park Lock Solenoid. 1. Replace Shift Lever Assem-
bly.
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 PED-
AL1. Response Characteristic Control
Loop.1. Install K2 Disc Spring.
UPSHIFT 2-3, 3-4 SLIP-
PING1. Spring of Regulating Valve Pres-
sure 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 Defec-
tive.Replace Free Wheeling Clutch
F1.
21 - 40 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

CONDITION POSSIBLE CAUSES CORRECTION
HARD 3-2 DOWNSHIFT
WHEN DECELERATION
EVEN AFTER READAP-
TION1. K3 Idles. 1. Install TCM And/Or Electro-
hydraulic Control Unit.
NO RESP. DELAYED UP-
SHIFT, 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 AF-
TER FAST OFF (ACCEL-
ERATOR)1. Upshift Prevention To Realize Dy-
namical 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 Pow-
ered Vehicle Will Never Shift Into
5th Gear Below 250 km/h.1. Instruct Customer.
NO KICK DOWN SHIFT-
ING1. Accelerator Pedal Value < 95%. 1. Check Engine Control. Ad-
just 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 Nec-
essary.
2. Oil Filter Not Installed. 2. Install Oil Filter.
3. Free Wheeling Clutch F2 Defec-
tive.3. Replace Free Wheeling
Clutch F2, Hollow Shaft, and
Rear Sun Gear/Inner Disc Car-
rier K3.
GRABBING 2-3 COAST-
ING UPSHIFT AND/OR
BRAKE DOWNSHIFT1. Oil Level Too Low. 1. Check Oil Level. Add if Nec-
essary.
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.
DELAYED ENGAGEMENT,
NO TRANSFER OF POW-
ER IN R AND/OR D, ALSO
AT TIMES1. Oil Level Too Low. 1. Check Oil Level. Add if Nec-
essary.
2. Recognition Switch - Selector Le-
ver Position.2. Replace Recognition Switch
Only When Intermediate Posi-
tion 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 Proce-
dure (TCM, electrohydraulic
control unit or repair set).
5. Wrong Combination TCM/Electro-
hydraulic Control Unit.5. Check Combination TCM/
Electrohydraulic Control Unit.
Replace TCM Resp. Electrohy-
draulic Control Unit, if neces-
sary.
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 41

CONDITION POSSIBLE CAUSES CORRECTION
NO UPSHIFT OF 1ST
GEAR AT TIMES1. Connector Ballast Unit. Output
Speed Sensor Loose, Incorrectly
Contacted.1. Check Connectors, Replace
Output Speed sensor If Neces-
sary.
2. Output Speed Sensor Defective 2. Replace Output Speed Sen-
sor.
LEAKAGE AT THE AREA
OF THE ELECTRICAL
PLUG TO THE CONDUC-
TOR 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, Some-
times In The Control Module.4. Replace Conductor Plate.
LEAKAGE AT THE AREA
OF BELL HOUSING/
TORQUE CONVERTER1. Bolts (Torx M6) Outer Disc Carri-
er 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.
STANDARD PROCEDURE - ALUMINUM
THREAD REPAIR
Damaged or worn threads in the aluminum trans-
mission case and valve body can be repaired by the
use of Heli-CoilsŸ, or equivalent. This repair con-
sists of drilling out the worn-out damaged threads.
Then tap the hole with a special Heli-CoilŸ tap, or
equivalent, and installing a Heli-CoilŸ insert, or
equivalent, into the hole. This brings the hole back to
its original thread size.
Heli-CoilŸ, or equivalent, tools and inserts are
readily available from most automotive parts suppli-
ers.
REMOVAL
(1) Disconnect the negative (ground) battery cable.
CAUTION: Isolate ground lead to prevent accidental
contact.(2) Apply parking brake.
(3) Move gear selector lever to position ªNº.
(4) Remove oil drain plug (2) (Fig. 26) and drain
automatic transmission oil into a clean container.
21 - 42 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

(5) Remove oil filler pipe.
(a) Remove bolts (2) (Fig. 27) to cylinder head.
(b) Remove bolt (3) (Fig. 27) to transmission
flange and bolt (2) to transmission housing.
(c) Pull lower connection of oil filler pipe (1) (Fig.
27) out of the fill hole in the side of the transmis-
sion housing.
(d) Guide oil filler pipe (1) (Fig. 27) up and
out.
(6) Remove exhaust heat shield (5) (Fig. 28).
(7) Remove retaining bracket (4) (Fig. 28).(8) Detach propeller shaft (1) (Fig. 28) at transmis-
sion (Refer to 3 - DIFFERENTIAL & DRIVELINE/
PROPELLER SHAFT/PROPELLER SHAFT -
REMOVAL). Move propeller shaft to the right and tie
up.
(9) Remove the cooler lines at transmission.
(a) Remove bracket for the oil cooler feed and
return lines (1) (Fig. 29) from engine oil pan
flange. Detail shows right side of motor. Position is
mirrored for the left side of engine.
(b) Detach bracket of cable retainer (4) (Fig. 30)
from the threaded shank of a engine oil pan bolt
(5).
(c) Press cable retainer (4) (Fig. 30) down and
out.
(d) Remove the bolts holding the oil cooler lines
(6) (Fig. 31) to the left and right sides of transmis-
sion and hang the lines to the side.
Fig. 26 Drain Transmission
1 - SEAL
2 - DRAIN PLUG
Fig. 27 Fill Tube
1 - FILL TUBE
2 - BOLTS TO CYLINDER HEAD AND TRANSMISSION HOUS-
ING
3 - BOLT TO TRANSMISSION FLANGE
Fig. 28 Propeller Shaft and Heat Shield
1 - PROPELLER SHAFT
2 - BOLT
3 - BOLT
4 - RETAINING BRACKET
5 - HEAT SHIELD
6 - WASHER
7 - BOLT
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 43

(10) Disconnect the transmission electrical connec-
tor (2) (Fig. 32) from transmission and hang to the
side. Turn sealing ring (3) counterclockwise and dis-
connect plug connection (2).
(11) Detach shift cable at transmission.
(a) Unlatch ball socket latch (Fig. 33) of cable.
(b) Unclip shift cable retainer from retainer
bracket. When pulling out cable, press together
hooks of shift cable retainer at the points shown
(arrows).
(c) Pull shift cable out of ball socket. Ball socket
can remain on transmission lever.
Fig. 29 Cooler Line Supports
1 - COOLER LINES
Fig. 30 Cable Support
1 - CABLE
2 - BOLT
Fig. 31 Driver's Side Cooler Line
1 - COOLER LINE
Fig. 32 Transmission Electrical Connector and
Cooler Line
1 - COOLER LINE
2 - TRANSMISSION ELECTRICAL CONNECTOR
3 - SEALING RING
21 - 44 AUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATIONVA

(12) Remove the torque converter bolts.
(a) Remove the steering gear (1) (Fig. 34) from
the chassis crossmember.
(b) Lower the steering gear (1) (Fig. 34) down-
wards.
(c) Remove the plastic torque converter access
cover (1) (Fig. 35) at back of engine flange.
(d) Rotate engine by hand until bolts (2) (Fig.
35) are in front of opening. Rotate engine forwards
at crankshaft.
(e) To remove bolts, position a ratchet with long
extension and joint nut as shown (Fig. 36).
(f) Remove the two bolts (2) (Fig. 35) at each of
the three locations at circumference of driving
plate.
(13) Remove torque converter drain plug and drain
automatic transmission oil into a clean container. Re-
install the drain plug and torque the plug to 14 N´m
(130 in.lbs.).
(14) Support engine. Insert wooden block between
oil pan and front chassis crossmember beam.
(15) Remove vent hose bracket and tie back to one
side.
Fig. 33 Shift Cable at Transmission
1 - SHIFT CABLE
2 - TRANSMISSION SHIFT LEVER
Fig. 34 Steering Gear
1 - STEERING GEAR
2 - BRACKET
Fig. 35 Torque Converter Access Cover
1 - TORQUE CONVERTER ACCESS COVER
2 - BOLT
Fig. 36 Torque Converter Bolts Access
1 - BOLT
2 - STABILIZER BAR
3 - REINFORCEMENT PLATE
4 - OPENING
5 - CHASSIS CROSSMEMBER
6 - STEERING GEAR
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 45