transmission MERCEDES-BENZ SPRINTER 2006 Workshop Manual

COOLING
TABLE OF CONTENTS
page page
COOLING
OPERATION - COOLING SYSTEM...........1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS.............................1COOLING SYSTEM.....................2
ACCESSORY DRIVE.......................5
ENGINE.................................9
COOLING
OPERATION - COOLING SYSTEM
The cooling system regulates engine operating tem-
perature. It allows the engine to reach normal oper-
ating temperature as quickly as possible. It also
maintains normal operating temperature and pre-
vents overheating.
The cooling system also provides a means of heat-
ing the passenger compartment and cooling the auto-
matic transmission fluid (if equipped). The cooling
system is pressurized and uses a centrifugal water
pump to circulate coolant throughout the system.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRELIMINARY
CHECKS
ENGINE COOLING SYSTEM OVERHEATING
Establish what driving conditions caused the com-
plaint. Abnormal loads on the cooling system such as
the following may be the cause:
²PROLONGED IDLE
²VERY HIGH AMBIENT TEMPERATURE
²SLIGHT TAIL WIND AT IDLE
²SLOW TRAFFIC
²TRAFFIC JAMS
²HIGH SPEED OR STEEP GRADES
Driving techniques that avoid overheating are:
²Idle with A/C off when temperature gauge is at
end of normal range.²Increasing engine speed for more air flow is rec-
ommended.
TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
AIR CONDITIONING; ADD - ON OR AFTER MARKET:
A maximum cooling package should have been
ordered with vehicle if add-on or after market A/C is
installed. If not, maximum cooling system compo-
nents should be installed for model involved per
manufacturer's specifications.
RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect cooling system.
This may be:
²Engine adjustments (incorrect timing)
²Slipping engine accessory drive belt(s)
²Brakes (possibly dragging)
²Changed parts. Incorrect water pump or pump
rotating in wrong direction due to belt not correctly
routed
²Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, (Refer to 7 - COOLING - DIAGNOSIS AND
TESTING)
VACOOLING 7 - 1

Operate tester pump to apply 103.4 kPa (15 psi)
pressure to system. If hoses enlarge excessively or
bulges while testing, replace as necessary. Observe
gauge pointer and determine condition of cooling sys-
tem according to following criteria:
Holds Steady:If pointer remains steady for two
minutes, serious coolant leaks are not present in sys-
tem. However, there could be an internal leak that
does not appear with normal system test pressure. If
it is certain that coolant is being lost and leaks can-
not be detected, inspect for interior leakage or per-
form Internal Leakage Test.
Drops Slowly:Indicates a small leak or seepage
is occurring. Examine all connections for seepage or
slight leakage with a flashlight. Inspect radiator,
hoses, gasket edges and heater. Seal small leak holes
with a Sealer Lubricant (or equivalent). Repair leak
holes and inspect system again with pressure
applied.
Drops Quickly:Indicates that serious leakage is
occurring. Examine system for external leakage. If
leaks are not visible, inspect for internal leakage.
Large radiator leak holes should be repaired by a
reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION
Remove engine oil pan drain plug and drain a
small amount of engine oil. If coolant is present in
the pan, it will drain first because it is heavier than
oil. An alternative method is to operate engine for a
short period to churn the oil. After this is done,
remove engine dipstick and inspect for water glob-ules. Also inspect transmission dipstick for water
globules and transmission fluid cooler for leakage.
WARNING: WITH RADIATOR PRESSURE TESTER
TOOL INSTALLED ON RADIATOR, DO NOT ALLOW
PRESSURE TO EXCEED 110 KPA (20 PSI). PRES-
SURE WILL BUILD UP QUICKLY IF A COMBUSTION
LEAK IS PRESENT. TO RELEASE PRESSURE,
ROCK TESTER FROM SIDE TO SIDE. WHEN
REMOVING TESTER, DO NOT TURN TESTER MORE
THAN 1/2 TURN IF SYSTEM IS UNDER PRESSURE.
Operate engine without pressure cap on coolant
container until thermostat opens. Attach a Pressure
Tester to container. If pressure builds up quickly it
indicates a combustion leak exists. This is usually
the result of a cylinder head gasket leak or crack in
engine. Repair as necessary.
If there is not an immediate pressure increase,
pump the Pressure Tester. Do this until indicated
pressure is within system range of 110 kPa (16 psi).
Fluctuation of gauge pointer indicates compression or
combustion leakage into cooling system.
Because the vehicle is equipped with a catalytic
converter,do notremove spark plug cables or short
out cylinders to isolate compression leak.
If the needle on dial of pressure tester does not
fluctuate, race engine a few times to check for an
abnormal amount of coolant or steam. This would be
emitting from exhaust pipe. Coolant or steam from
exhaust pipe may indicate a faulty cylinder head gas-
ket, cracked engine cylinder block or cylinder head.
A convenient check for exhaust gas leakage into
cooling system is provided by a commercially avail-
able Block Leak Check tool. Follow manufacturers
instructions when using this product.
COMBUSTION LEAKAGE TEST - WITHOUT PRES-
SURE TESTER
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean and suitably marked
container for reuse.
WARNING: Do not remove cylinder block drain
plugs or loosen radiator drain with system hot and
under pressure. serious burns from coolant can
occur.
Drain sufficient coolant to allow thermostat
removal.
Remove accessory drive belt.
Add coolant to pressure container to bring level to
within 6.3 mm (1/4 in) of top of thermostat housing.
CAUTION: Avoid overheating. Do not operate
engine for an excessive period of time. Open drain-
cock immediately after test to eliminate boil over.
Fig. 2 PRESSURE TESTING
1 - PRESSURE RESERVOIR CAP
2 - PRESSURE RESERVOIR
3 - PRESSURE TESTER
VAENGINE 7 - 11

(8) Unplug wiring connector at coolant level sensor
(Fig. 9).
(9) Detach coolant hose at bottom right of radiator
(Fig. 9).
(10) Detach transmission cooler lines at radiator
(Fig. 9).
(11) Remove the radiator trim from the left and
right (Fig. 9).
(12) Remove radiator fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL).
(13) Remove bolts securing intercooler to radiator.
(14) Remove screws and upper radiator trim from
radiator.
(15) Move condenser/intercooler/power steering
cooler assembly forward.
(16) Lift the radiator assembly up and out of the
rubber grommets (Fig. 9).
Fig. 9 RADIATOR ASSEMBLY
1 - COOLANT HOSE 8 - ATF LINE
2 - SENSOR HARNESS CONNECTOR 9 - LEFT RADIATOR TRIM PANEL
3 - HYDRAULIC HOSE 10 - RIGHT RADIATOR TRIM PANEL
4 - CHARGE AIR HOSE 11 - RADIATOR
5 - HYDRAULIC HOSE 12 - ATF LINE
6 - RUBBER GROMMET 13 - COOLANT HOSE
7 - COOLANT HOSE 14 - COOLANT RESERVOIR
7 - 18 ENGINEVA

(17) Take off charge air cooler together with cool-
ing loop of the steering at the radiator (Fig. 10).
(18) Remove bottom radiator trim (Fig. 10).
(19) Detach coolant hose at radiator.
(20) Detach coolant pipe together with coolant
hose at the fan shroud.
(21) Remove radiator fan shroud (Fig. 10).
INSTALLATION
(1) Install fan shroud to radiator (Fig. 10).
(2) Attach coolant pipe with hoses to fan shroud
(Fig. 10).
(3) Attach coolant hose at radiator (Fig. 10).
(4) Install bottom radiator trim (Fig. 10).
(5) Install charge air cooler along with cooling loop
of the power steering, to radiator (Fig. 10).
(6) Install radiator assembly into the rubber grom-
mets (Fig. 9).
(7) Install both right and left side radiator trim
panels (Fig. 9).
(8) Attach the transmission cooler lines (Fig. 9).
(9) Attach coolant hose to the bottom right of the
radiator (Fig. 9).
(10) Attach both power steering hydraulic lines
(Fig. 9).
(11) Connect coolant level sensor electrical connec-
tor (Fig. 9).
(12) Connect coolant hoses to the coolant reservoir,
radiator and water pump (Fig. 9).(13) Attach air intake pipe at the body.
(14) Attach charge air hose at air intake.
(15) Attach charge air hose at turbocharger.
(16) Install A/C condenser.
(17) Install front bumper.
(18) Install front end cross member.
(19) Refill power steering to proper level.
(20) Refill transmission to proper level.
(21) Close radiator drain plug and refill the cooling
system (Refer to 7 - COOLING/ENGINE/COOLANT -
STANDARD PROCEDURE).
(22) Recharge air conditioning (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(23) Run engine until warm and check for leaks.
RADIATOR PRESSURE CAP
DESCRIPTION
All vehicles are equipped with a pressure cap (Fig.
11). This cap releases pressure at some point within
a range of 124-145 kPa (18-21 psi). The pressure
relief point (in pounds) is engraved on top of the cap
The cooling system will operate at pressures
slightly above atmospheric pressure. This results in a
higher coolant boiling point allowing increased radi-
ator cooling capacity. The cap contains a spring-
loaded pressure relief valve. This valve opens when
system pressure reaches the release range of 124-145
kPa (18-21 psi).
A rubber gasket seals the radiator filler neck. This
is done to maintain vacuum during coolant cool-down
and to prevent leakage when system is under pres-
sure.
Fig. 10 RADIATOR AND FAN SHROUD
1 - CLIP
2 - SHROUD
3 - RADIATOR
4 - BOTTOM RADIATOR TRIM PANEL
5 - CHARGE AIR COOLER
6 - TOP RADIATOR TRIM PANEL
7 - POWER STEERING COOLER LOOP
VAENGINE 7 - 19

ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
CENTRAL TIMER MODULE
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - CENTRAL TIMER
MODULE.............................2
REMOVAL.............................2
INSTALLATION..........................3
CONTROLLER ANTILOCK BRAKE
DESCRIPTION..........................3
REMOVAL.............................3INSTALLATION..........................3
ENGINE CONTROL MODULE
DESCRIPTION..........................3
REMOVAL.............................6
INSTALLATION..........................6
TRANSMISSION CONTROL MODULE
DESCRIPTION..........................6
OPERATION............................7
STANDARD PROCEDURE - TCM ADAPTATION . 10
CENTRAL TIMER MODULE
DESCRIPTION
The central timer module (CTM) is located beneath
the driver seat. The CTM uses information carried on
the programmable communications interface (PCI)
data bus network along with many hard wired inputs
to monitor many sensor and switch inputs. In
response to those inputs, the circuitry and program-
ming of the CTM allow it to supply the vehicle occu-
pants with audible and visual information, and to
control and integrate many functions and features of
the vehicle through both hard wired outputs and the
transmission of message outputs to other modules in
the vehicle over the PCI data bus.
The features that the CTM supports or controls
include the following:
²Central Locking- The CTM on vehicles
equipped with the optional Vehicle Theft Security
System (VTSS) includes a central locking/unlocking
feature.
²Enhanced Accident Response- The CTM pro-
vides an optional enhanced accident response fea-
ture. This is a programmable feature.
²Panic Mode- The CTM provides support for
the optional RKE system panic mode including horn,
headlamp, and park lamp flash features.
²Power Lock Control- The CTM provides the
optional power lock system features, including sup-
port for the automatic door lock and door lock inhibit
modes.
²Programmable Features- The CTM provides
support for certain programmable features.
²Remote Keyless Entry- The CTM provides
the optional Remote Keyless Entry (RKE) system fea-
tures, including support for the RKE Lock (with
optional horn and park lamps flash), Unlock (with
park lamps flash, driver-door-only unlock, andunlock-all-doors), Panic, and illuminated entry
modes, as well as the ability to be programmed to
recognize up to four RKE transmitters. The RKE
horn, driver-door-only unlock, and unlock-all-doors
features are programmable.
²Vehicle Theft Security System- The CTM
provides control of the optional Vehicle Theft Secu-
rity System (VTSS) features, including support for
the central locking/unlocking mode and control of the
Security indicator in the instrument cluster.
Hard wired circuitry connects the CTM to the elec-
trical system of the vehicle. Refer to the appropriate
wiring information.
Many of the features in the vehicle controlled or
supported by the CTM are programmable using the
DRBIIItscan tool. However, if any of the CTM hard-
ware components are damaged or faulty, the entire
CTM unit must be replaced. The hard wired inputs
or outputs of all CTM versions can be diagnosed
using conventional diagnostic tools and methods;
however, for diagnosis of the CTM or the PCI data
bus, the use of a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
OPERATION
The central timer module (CTM) monitors many
hard wired switch and sensor inputs as well as those
resources it shares with other modules in the vehicle
through its communication over the programmable
communications interface (PCI) data bus network.
The internal programming and all of these inputs
allow the CTM to determine the tasks it needs to
perform and their priorities, as well as both the stan-
dard and optional features that it should provide.
The CTM then performs those tasks and provides
those features through both PCI data bus communi-
cation with other modules and hard wired outputs
through a number of driver circuits, relays, and
VAELECTRONIC CONTROL MODULES 8E - 1

rate and boost pressure are adjusted to the actual
injection quantity.
²Injection valve quantity drift compensation in
full load range: this function is to limit the maximum
injection quantity for engine protection. The injection
quantity signal is compared to the injection quantity
calculated from the oxygen sensor signal and MAF
signal. If the comparison shows that the actual injec-
tion quantity is too high, it is limited to the maxi-
mum permissible injection quantity
²Air-fuel ratio controlled smoke limiter (full load):
the smoke limiter limits the injection quantity on the
basis of the air-fuel ratio permissible at the smoke
limit depending on the measure mass air flow and
the calculated EGR rate. As a consequence, the gen-
eration of smoke due to an excess injection quantity
is avoided under all operating conditions. At the
same time, the oxygen sensor signal is used to
ensure that the air-fuel ratio is adjusted accordingly
A function referred to as air flow sensor drift com-
pensation detects and corrects the possible drifting of
the MAF sensor by comparing the air mass measured
by the MAF with the projected air mass as it is cal-
culated by the ECM in consideration of various influ-
encing conditions. It is the air flow drift
compensation that gives the MAF air mass measure-
ment the precision needed to use it for the function
mentioned above. The high precision of the MAF
measurement enables the calculation of the actual
injection quantity from the measured air mass and
from the oxygen sensor signal in order to correct
injection quantity. The MAF signal can also be used
as a input parameter for the smoke limiter.
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the ECM harness connectors (Fig.
4).
(3) Grasp ECM and pull down firmly to release
ECM from the retaining bracket tensioning springs
(Fig. 4).
INSTALLATION
NOTE: THE ECM MUST BE PROGRAMMED TO SUP-
PORT THE VEHICLE OPTIONS PACKAGE.
(1) Position the ECM into the guide of the retain-
ing bracket (Fig. 4).
(2) Carefully push the ECM in to the bracket until
the bracket tensioning springs engage (Fig. 4).
(3) Connect the ECM wiring harness connectors
(Fig. 4).
(4) Connect negative battery cable.
TRANSMISSION CONTROL
MODULE
DESCRIPTION
The transmission control module (TCM) receives,
processes and sends various digital and analog sig-
nals related to the automatic transmission. In addi-
tion, it processes information received from other
vehicle systems, such as engine torque and speed,
accelerator pedal position, wheel speed, kick-down
switch, traction control information, etc.
The TCM is located under the driver's seat and is
connected to other control modules via a CAN bus. It
controls all shift functions to achieve smooth shift
comfort in all driving situations considering:
²Vehicle speed.
²Transmission status.
Fig. 4 ECM
1 - BRACKET
2 - ECM
3 - BRACKET TENSIONING SPRINGS
8E - 6 ELECTRONIC CONTROL MODULESVA

²Position of selector lever.
²Selected shift range.
²CAN signals.
²Engine Status.
Engine speed limits may be reached in all gears
with full throttle or in kick-down operation. In for-
ward driving, the shift range of the forward gears
can be adjusted by the operator by tipping the selec-
tor lever to the left or right (AutoStick). However, the
TCM features a downshift inhibitor to prevent the
engine from overspeeding.
OPERATION
The transmission control module (TCM) deter-
mines the current operating conditions of the vehicle
and controls the shifting process for shift comfort and
driving situations. It receives this operating data
from sensors and broadcast messages from other
modules.
The TCM uses inputs from several sensors that are
directly hardwired to the controller and it uses sev-
eral indirect inputs that are used to control shifts.
This information is used to actuate the proper sole-
noids in the valve body to achieve the desired gear.
The shift lever assembly (SLA) has several items
that are monitored by the TCM to calculate shift
lever position. The reverse light switch, an integral
part of the SLA, controls the reverse light relay con-
trol circuit. The Brake/Transmission Shift Interlock
(BTSI) solenoid and the park lockout solenoid (also
part of the SLA) are controlled by the TCM.
The ECM and ABS broadcast messages over the
controller area network (CAN C) bus for use by the
TCM. The TCM uses this information, with other
inputs, to determine the transmission operating con-
ditions.
The TCM:
²determines the momentary operating conditions
of the vehicle.
²controls all shift processes.
²considers shift comfort and the driving situation.
The TCM controls the solenoid valves for modulat-
ing shift pressures and gear changes. Relative to the
torque being transmitted, the required pressures are
calculated from load conditions, engine rpm, vehicle
speed, and ATF temperature.
The following functions are contained in the TCM:
²Shift Program
²Downshift Safety
²Torque Converter Lock-Up Clutch.
²Adaptation.
This transmission does not have a TCM relay.
Power is supplied to the SLA and the TCM directly
from the ignition.
The TCM continuously checks for electrical prob-
lems, mechanical problems, and some hydraulic prob-
lems. When a problem is sensed, the TCM stores a
diagnostic trouble code (DTC). Some of these codescause the transmission to go into ªLimp-Inº or
ªdefaultº mode. Some DTCs cause permanent
Limp-In and others cause temporary Limp-In. The
NAG1 defaults in the current gear position if a DTC
is detected, then after a key cycle the transmission
will go into Limp-in, which is mechanical 2nd gear.
Some DTCs may allow the transmission to resume
normal operation (recover) if the detected problem
goes away. A permanent Limp-In DTC will recover
when the key is cycled, but if the same DTC is
detected for three key cycles the system will not
recover and the DTC must be cleared from the TCM
with the DRBIIItscan tool.
TCM SIGNALS
The TCM registers one part of the input signals by
direct inputs, the other part by CAN C bus. In addi-
tion to the direct control of the actuators, the TCM
sends various output signals by CAN C bus to other
control modules.
Selector Lever Position
The TCM monitors the SLA for all shift lever posi-
tions via the CAN bus.
ATF Temperature Sensor
The ATF temperature sensor is a positive temper-
ature co-efficient (PTC) thermistor. It measures the
temperature of the transmission fluid and is a direct
input signal for the TCM. The temperature of the
ATF has an influence on the shifttime and resulting
shift quality. As the temperature rises, resistance
rises, and therefore, the probing voltage is decreas-
ing. Because of its registration, the shifting process
can be optimized in all temperature ranges.
The ATF temperature sensor is wired in series
with the park/neutral contact. The temperature sig-
nal is transmitted to the TCM only when the reed
contact of the park/neutral contact is closed because
the TCM only reads ATF temperature while in any
forward gear, or REVERSE. When the transmission
is in PARK or NEUTRAL, the TCM will substitute
the engine temperature for the ATF temperature.
Starter Interlock
The TCM monitors a contact switch wired in series
with the transmission temperature sensor to deter-
mine PARK and NEUTRAL positions. The contact
switch is open in PARK and NEUTRAL. The TCM
senses transmission temperature as high (switch
supply voltage), confirming switch status as open.
The TCM then broadcasts a message over CAN bus
to confirm switch status. The PCM receives this
information and allows operation of the starter cir-
cuit.
VAELECTRONIC CONTROL MODULES 8E - 7

N2 and N3 Speed Sensors
The N2 and N3 Input Speed Sensors are two Hall-
effect speed sensors that are mounted internally in
the transmission and are used by the TCM to calcu-
late the transmission's input speed. Since the input
speed cannot be measured directly, two of the drive
elements are measured. Two input speed sensors
were required because both drive elements are not
active in all gears.
CAN C Bus Indirect Input Signals
A 2.5-volt bias (operating voltage) is present on the
CAN C bus any time the ignition switch is in the
RUN position. Both the TCM and the ABS apply this
bias. On this vehicle, the CAN C bus is used for mod-
ule data exchange only. The indirect inputs used on
the NAG1 electronic control system are:
²Wheel Speed Sensors.
²Brake Switch.
²Engine RPM.
²Engine Temperature.
²Cruise Control Status.
²Gear Limit Request.
²Throttle Position - 0% at idle, 100% at WOT. If
open, TCM assumes idle (0% throttle opening).
²Odometer Mileage
²Maximum Effective Torque.
²Engine in Limp-In Mode/Mileage Where DTC
Was Set.
BRAKE TRANSMISSION SHIFT INTERLOCK (BTSI)
The BTSI solenoid prevents shifting out of the
PARK position until the ignition key is in the RUN
position and the brake pedal is pressed. The TCM
controls the ground while the ignition switch supplies
power to the BTSI solenoid. The PCM monitors the
brake switch and broadcasts brake switch status
messages over the CAN C bus. If the park brake is
depressed and there is power (Run/Start) to SLA, the
BTSI solenoid deactivates.
SHIFT SCHEDULES
The basic shift schedule includes up and down-
shifts for all five gears. The TCM adapts the shift
program according to driving style, accelerator pedal
position and deviation of vehicle speed. Influencing
factors are:
²Road Conditions.
²Incline, Decline and Altitude.
²Trailer Operation, Loading.
²Engine Coolant Temperature.
²Cruise Control Operation.
²Sporty Driving Style.
²Low and High ATF Temperature.
Upshift
To :1-2 2-3 3-4 4-5
Activat-
ed By
Sole-
noid:1-2/4-5 2-3 3-4 1-2/4-5
Shift
Point
(at
35.2%
of throt-
tle)17.8
km/h
(11.6
mph)32.1
km/h
(19.95
mph)67.5
km/h
(41.94
mph)73.8
km/h
(45.86
mph)
Down-
shift
From:5-4 4-3 3-2 2-1
Activat-
ed By
Sole-
noid:1-2/4-5 3-4 2-3 1-2/4-5
Shift
Point55.7
km/h
(34.61
mph)40.5
km/h
(25.17
mph)24.4
km/h
(15.16
mph)15.1
km/h
(9.38
mph)
DOWNSHIFT SAFETY
Selector lever downshifts are not performed if inad-
missible high engine rpm is sensed.
ADAPTATION
To equalize tolerances and wear, an automatic
adaptation takes place for:
²Shift Time.
²Clutch Filling Time.
²Clutch Filling Pressure.
²Torque Converter Lock-Up Control.
Adaptation data may be stored permanently and to
some extent, can be diagnosed.
Driving Style Adaptation
The shift point is modified in steps based on the
information from the inputs. The control module
looks at inputs such as:
²vehicle acceleration and deceleration (calculated
by the TCM).
²rate of change as well as the position of the
throttle pedal (fuel injection information from the
ECM).
²lateral acceleration (calculated by the TCM).
²gear change frequency (how often the shift
occurs).
Based on how aggressive the driver is, the TCM
moves up the shift so that the present gear is held a
8E - 8 ELECTRONIC CONTROL MODULESVA

little longer before the next upshift. If the driving
style is still aggressive, the shift point is modified up
to ten steps. If the driving returns to normal, then
the shift point modification also returns to the base
position.
This adaptation has no memory. The adaptation to
driving style is nothing more than a shift point mod-
ification meant to assist an aggressive driver. The
shift points are adjusted for the moment and return
to base position as soon as the inputs are controlled
in a more rational manner.
Shift Time Adaptation (Shift Overlap Adaptation, Working
Pressure)
Shift time adaptation is the ability of the TCM to
electronically alter the time it takes to go from one
gear to another. Shift time is defined as the time it
takes to disengage one shift member while another is
being applied. Shift time adaptation is divided into
four categories:
1. Accelerating upshift, which is an upshift under
a load. For shift time adaptation for the 1-2 upshift
to take place, the transmission must shift from 1st to
2nd in six different engine load ranges vs. transmis-
sion output speed ranges.
2. Decelerating upshift, which is an upshift under
no load. This shift is a rolling upshift and is accom-
plished by letting the vehicle roll into the next gear.
3. Accelerating downshift, which is a downshift
under load. This shift can be initiated by the throttle,
with or without kickdown. The shift selector can also
be used.
4. Decelerating downshift, which is accomplished
by coasting down. As the speed of the vehicle
decreases, the transmission downshifts.
Fill Pressure Adaptation (Apply Pressure Adaptation, Modu-
lating Pressure)
Fill pressure adaptation is the ability of the TCM
to modify the pressure used to engage a shift mem-
ber. The value of this pressure determines how firm
the shift will be.
²If too much pressure is used, the shift will be
hard.
²If too little pressure is used, the transmission
may slip.
The pressure adjustment is needed to compensate
for the tolerances of the shift pressure solenoid valve.
The amount the solenoid valve opens as well as how
quickly the valve can move, has an effect on the pres-
sure. The return spring for the shift member pro-
vides a resistance that must be overcome by the
pressure in order for shift member to apply. These
return springs have slightly different values. This
also affects the application pressure and is compen-
sated for by fill pressure adaptation.Fill Time Adaptation (Engagement Time Adaptation)
Fill time is the time it takes to fill the piston cav-
ity and take up any clearances for a friction element
(clutch or brake). Fill time adaptation is the ability of
the TCM to modify the time it takes to fill the shift
member by applying a preload pressure.
CONTROLLER MODES OF OPERATION
Permanent Limp - In Mode
When the TCM determines there is a non-recover-
able condition present that does not allow proper
transmission operation, it places the transmission in
permanent Limp-In Mode. When the condition occurs
the TCM turns off all solenoids as well as the sole-
noid supply output circuit. If this occurs while the
vehicle is moving, the transmission remains in the
current gear position until the ignition is turned off
or the shifter is placed in the ªPº position. When the
shifter has been placed in ªP,º the transmission only
allows 2nd gear operation. If this occurs while the
vehicle is not moving, the transmission only allows
operation in 2nd gear.
Temporary Limp - In Mode
This mode is the same as the permanent Limp-In
Mode except if the condition is no longer present, the
system resumes normal operation.
Under Voltage Limp - In Mode
When the TCM detects that system voltage has
dropped below 8.5 volts, it disables voltage-depen-
dant diagnostics and places the transmission in the
temporary Limp-In Mode. When the TCM senses
that the voltage has risen above 9.0 volts, normal
transmission operation is resumed.
Hardware Error Mode
When the TCM detects a major internal error, the
transmission is placed in the permanent Limp-In
Mode and ceases all communication over the CAN
bus. When the TCM has entered this mode normal
transmission operation does not resume until all
DTCs are cleared from the TCM.
Loss of Drive
If the TCM detects a situation that has resulted or
may result in a catastrophic engine or transmission
problem, the transmission is placed in the neutral
position. Improper Ratio, Input Sensor Overspeed or
Engine Overspeed DTCs cause the loss of drive.
Controlled Limp - in Mode
When a failure does not require the TCM to shut
down the solenoid supply, but the failure is severe
enough that the TCM places the transmission into a
VAELECTRONIC CONTROL MODULES 8E - 9

predefined gear, there are several shift performance
concerns. For instance, if the transmission is slip-
ping, the controller tries to place the transmission
into 3rd gear and maintain 3rd gear for all forward
drive conditions.
STANDARD PROCEDURE - TCM ADAPTATION
The adaptation procedure requires the use of the
appropriate scan tool. This program allows the elec-
tronic transmission system to re-calibrate itself. This
will provide the proper baseline transmission opera-
tion. The adaptation procedure should be performed
if any of the following procedures are performed:
²Transmission Assembly Replacement
²Transmission Control Module Replacement
²Clutch Plate and/or Seal Replacement
²Electrohydraulic Unit Replacement or Recondi-
tion
(1) With the scan tool, reset the Transmission
adaptives. Resetting the adaptives will set the adap-
tives to factory settings.
NOTE: Perform the Coast Down Adaptations first.
The Transmission Temperature must be greater
than 60ÉC (140ÉF) and less than 70ÉC (158ÉF). Fail-
ure to stay within these temperature ranges will
void the procedure.
(2) Drive the vehicle until the transmission tem-
perature is in the specified range.
(3) Perform 4 to 5 coast downs from 5th to 4th
gear and then 4th to 3rd gear.
NOTE: For Upshift adaptation, the Transmission
temperature must be greater than 60ÉC (140ÉF) and
less than 100ÉC (212ÉF). Failure to stay within these
temperature ranges will void this procedure.
(4) From a stop, moderately accelerate the vehicle
and obtain all forward gear ranges while keeping the
Engine RPM below 1800 RPM. Repeat this procedure
4 to 5 times.
(5) Obtaining 5th gear may be difficult at 1800
RPM. Allow the transmission to shift into 5th gear at
a higher RPM then lower the RPM to 1800 and per-
form manual shifts between 4th and 5th gears using
the shift lever.
(6) The TCM will store the adaptives every 10
minutes. After completion of the adaptation proce-
dure make sure the vehicle stays running for at least
10 minutes.
(7) It is possible to manually store the adaptives
under the 10 minute time frame using the DRBIIIt
Store Adaptives procedure.
8E - 10 ELECTRONIC CONTROL MODULESVA