
ITEM FEATURES APPLICATIONS SERVICE TEMP
High Density Ure-
thane FoamTear resistant, highly resilient
and durable.Between metal and metal, met-
al and plastic. Water-resistant.
Examples: I/P, heavy metal rat-
tles, isolating brackets.-40É to 180É Fahr-
enheit
(-40É to 82É Celsius)
Open Cell Foam
TapeSoft foam conforms to irregular
surfaces.Wire harness and connector
wrap.
Examples: Seals, gasket, wir-
ing, heat ducts.-40É to 180É Fahr-
enheit
(-40É to 82É Celsius)
Closed Cell Low
Density Foam TapeSoft, conformable. Water-resis-
tant.Wherever bulk is needed. Pre-
vents closing flutters and rat-
tles when applied to door wa-
tershield.
Examples: Door, I/P.-40É to 180É Fahr-
enheit
(-40É to 82É Celsius)
NYETGrease 880 Long life. Suspensions.
Examples: Strut busings, sway
bars.-40É to 390É Fahr-
enheit
(-40É to 200É Cel-
sius)
KrytoxTOil Long life. Will not dry out or
harm plastics or rubber.When access is not possible,
oil will migrate to condition.
Vinyl, rubber, plastic, metal.
Examples: Convertible top
bushings, pull cups trim panel
inserts.-30É to 400É Fahr-
enheit
(-34É to 205É Cel-
sius)
KrytoxTGrease Long life. Will not dry out or
harm plastics or rubber.Vinyl, rubber, plastic, metal,
glass.
Examples: Weather-strips,
backlite and windshield mold-
ings.-30É to 400É Fahr-
enheit
(-34É to 205É Cel-
sius)
SPECIFICATIONS
TORQUE SPECIFICATIONS
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Front door check bracket bolt/nut 6 Ð 53
Front door check to a-pillar M6 bolts 10 Ð 89
Front door check to a-pillar M8 bolts 35 26 Ð
Front door check to door fasteners 10 Ð 89
Front door exterior handle 10 Ð 89
Front door hinge bolts 25 18 Ð
Front door latch assembly bolts 10 Ð 89
Front door latch striker bolts 28 18 Ð
Front door regulator carrier plate bolts 10 Ð 89
Front door reinforcement bolts 21 15 Ð
Front door striker bolts 25 18 Ð
Front seat back mounting bolts 20 15 Ð
Front seat back stop bolt 20 15 Ð
Front seat mounting bolts 25 18 Ð
Hood hinge bolts/nuts 23 17 Ð
VABODY 23 - 11

(7) Install mirror. (Refer to 23 - BODY/EXTERI-
OR/SIDE VIEW MIRROR - INSTALLATION)
(8) Adjust door if required. (Refer to 23 - BODY/
DOOR - FRONT/DOOR - ADJUSTMENTS)
(9) Connect battery negative cable.
ADJUSTMENTS
ADJUSTMENT
NOTE: Door adjustment measurements should be
taken from stationary or welded body panels like
the roof, rocker or quarter panels.
²During adjustment procedures, it is recom-
mended that all the hinge fasteners be loosened
except for the upper most fasteners. Adjustments
can be made using the upper bolts to hold the door
with final torque of the fasteners occurring after
correct door positioning is achieved.
²A suitable body sealant should be used when
removing or moving the hinges.
(1) Check door alignment. (Refer to 23 - BODY/
BODY STRUCTURE/GAP AND FLUSH - SPECIFI-
CATIONS)
(2) If adjustment is required, remove latch striker.
(Refer to 23 - BODY/DOOR - FRONT/LATCH
STRIKER - REMOVAL)
(3) Remove side view mirror. (Refer to 23 - BODY/
EXTERIOR/SIDE VIEW MIRROR - REMOVAL)
(4) Loosen hinge bolts and adjust door gap and
align ridge pattern as necessary.
(5) Tighten hinge bolts to 25 N´m (18 ft. lbs.).
(6) Install latch striker and adjust flush measure-
ment as necessary. (Refer to 23 - BODY/DOOR -
FRONT/LATCH STRIKER - INSTALLATION)
(7) Install side view mirror. (Refer to 23 - BODY/
EXTERIOR/SIDE VIEW MIRROR - INSTALLA-
TION)
DOOR GLASS
REMOVAL
(1) Remove the regulator. (Refer to 23 - BODY/
DOOR - FRONT/WINDOW REGULATOR - POWER
or MANUAL - REMOVAL)
(2) Remove reinforcement bolts. (Fig. 6)(3) Carefully lower glass into door and out of run
channel.
(4) Remove glass from door.
INSTALLATION
(1) Carefully place glass into door and slide up
into run channel.
(2) Using wood wedge, tape or equivalent, secure
glass in the up position. (Fig. 7)
(3) Install reinforcement and install the bolts.
Fig. 6 FRONT DOOR GLASS
1 - DOOR RUN CHANNEL
2 - DOOR GLASS
3 - REINFORCEMENT BOLTS
Fig. 7 GLASS SUPPORT
1 - WOOD WEDGE (or equivalent)
2 - WINDOW GLASS
VADOOR - FRONT 23 - 15

OPERATION
The compressor clutch components provide the
means to engage and disengage the compressor from
the engine serpentine accessory drive belt. When the
clutch coil is energized, it magnetically draws the
clutch into contact with the pulley and drives the
compressor shaft. When the coil is not energized, the
pulley freewheels on the clutch hub bearing, which is
part of the pulley.
The compressor clutch engagement is controlled by
several components:
²A/C switch on the A/C-heater control panel
²Evaporator temperature sensor
²A/C pressure transducer
²Air temperature sensor
²CAN bus messages
The compressor clutch is de-energized under any of
the following conditions:
²Blocked compressor (thermal fuse in the pulley)
²Low pressure in the system
²Low evaporator temperature
²Hard acceleration (WOT)
²High coolant temperatures
STANDARD PROCEDURE
A / C COMPRESSOR CLUTCH AIR GAP
If a new clutch plate and/or clutch pulley are being
used, the air gap between the clutch plate and clutch
pulley must be checked using the following proce-
dure:
(1) Using feeler gauges, measure the air gap
between the clutch plate and the clutch pulley fric-
tion surfaces.
(2) If the air gap is not between specifications
(Refer to 24 - HEATING & AIR CONDITIONING -
SPECIFICATIONS), add or subtract shims until the
desired air gap is obtained.
NOTE: The shims may compress after tightening
the compressor shaft bolt. Check the air gap in four
or more places on the clutch plate to verify that the
air gap is still correct. Spin the clutch pulley before
making the final air gap check.
A / C COMPRESSOR CLUTCH BREAK - IN
After a new compressor clutch has been installed,
cycle the compressor clutch approximately twenty
times (five seconds on, then five seconds off). During
this procedure, set the heater-A/C control in the
Recirculation Mode, the A/C button in the on posi-
tion, the blower motor switch in the highest speed
position, and the engine speed at 1500 to 2000 rpm.
This procedure (burnishing) will seat the opposing
friction surfaces and provide a higher compressor
clutch torque capability.
REMOVAL
The refrigerant system can remain fully-charged
during compressor clutch, pulley, or coil replacement.
The compressor clutch can be serviced in the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Disconnect the engine wire harness connector
for the compressor clutch coil from the clutch coil
wire harness connector on the top of the compressor.
(4) Remove the retainer securing the compressor
clutch coil lead on the top of the compressor.
(5) Remove the bolt that secures the compressor
clutch to the compressor shaft (Fig. 2). If necessary, a
band-type oil filter wrench or strap wrench can be
placed around the clutch plate to aid in bolt
removal.
Fig. 1 A/C Compressor Clutch
1 - BOLT
2 - CLUTCH PLATE
3 - PULLEY AND BEARING
4 - FIELD COIL
5 - SNAP RING
6 - SNAP RING
7 - SHIM (2)
VACONTROLS-FRONT 24 - 9

INSIDE HANDLE ACTUATOR......23-33, 23-36
INSTRUMENT CLUSTER................8J-2
INSTRUMENT PANEL ANTENNA CABLE....8A-2
INSTRUMENT PANEL ASSEMBLY........23-59
INSTRUMENT PANEL CENTER BEZEL.....23-57
INSTRUMENT PANEL DUCTS...........24-51
INTAKE AIR PRESSURE SENSOR........14-43
INTAKE AIR TEMPERATURE SENSOR.....14-42
INTAKE MANIFOLD....................9-65
INTERIOR..........................23-70
INTERMEDIATE SHAFT.................19-4
INTERNATIONAL SYMBOLS...............0-9
INTERNATIONAL SYMBOLS...........Intro.-2
INTRUSION SENSOR...................8Q-1
IN - CAR TEMPERATURE SENSOR.......24-21
JUMP STARTING.......................0-6
KEY / LOCK CYLINDER.................19-5
KNUCKLE.............................2-5
LAMPS / LIGHTING - EXTERIOR..........8L-2
LAMPS / LIGHTING - INTERIOR.........8L-28
LATCH RELEASE CABLE...............23-52
LATCH RELEASE HANDLE..............23-52
LATCH STRIKER.....................23-18
LATCH ..................23-18, 23-33, 23-52
LATCH / LOCK CONTROL...............23-38
LATERAL ACCELERATION SENSOR........5-33
LEFT MOUNT.........................9-55
LEVER..............................5-26
LICENSE PLATE BRACKET..............23-48
LICENSE PLATE LAMP BULB...........8L-19
LICENSE PLATE LAMP UNIT............8L-19
LINKAGE............................19-9
LIQUID LINE........................24-77
LOCK CYLINDER.....................23-18
LOW BEAM HEADLAMP BULB..........8L-20
LOW FUEL INDICATOR................8J-19
LOW OIL LEVEL INDICATOR............8J-20
LOWER BALL JOINT....................2-6
LOWER CONTROL ARM.................2-6
LOWER ROLLER ARM.................23-37
MAINTENANCE INDICATOR.............8J-20
MAINTENANCE SCHEDULES..............0-8
MALFUNCTION INDICATOR LAMP (MIL) . . . 8J-21
MANIFOLD AIR FLOW (MAF) SENSOR....14-44
MASTER CYLINDER...................5-17
MASTER LOCK SWITCH................8N-1
METRIC SYSTEM...................Intro.-6
MODE DOOR CABLES.................24-21
MULTI - FUNCTION INDICATOR..........8J-22
MULTI - FUNCTION SWITCH............8L-21
O2 SENSOR.........................14-45
ODOMETER.........................8J-22
OIL COOLER & LINES..................9-56
OIL FILTER ..........................9-57
OIL JET .............................9-57
OIL PAN .............................9-58
OIL PUMP...........................9-61
OIL PUMP.........................21-154
OIL SENSOR.........................9-64
OIL ................................9-56
OPENING DIMENSIONS................23-93
OUTPUT SHAFT BEARING.............21-156
OUTPUT SHAFT SEAL................21-159
PAINT TOUCH - UP...................23-77
PAINT.............................23-77
PARK BRAKE INDICATOR..............8J-23
PARK BRAKE SWITCH.................8L-21
PARK LOCK CABLE..................21-160
PARKING BRAKE......................5-23
PASSENGER AIRBAG BRACKET.........8O-27
PASSENGER AIRBAG.................8O-24
PASSENGER HEATED SEAT SWITCH.....8G-13
PEDAL..............................5-19
PISTON & CONNECTING ROD............9-45
PISTON RINGS.......................9-52
PISTONS..........................21-163
PLANETARY GEARTRAIN..............21-164
PLUMBING.........................24-61
POWER BRAKE BOOSTER...............5-19
POWER DISTRIBUTION CENTER.......8W-97-3
POWER DISTRIBUTION..............8W-97-1
POWER MIRROR SWITCH..............8N-3
POWER MIRRORS....................8N-3
POWER OUTLET
...................8W-97-3
POWER WINDOW SWITCH
..............8N-5
POWER WINDOWS
....................8N-5
PROP ROD
.........................23-53
PROPELLER SHAFT
.................3-1, 3-7PUMP.............................19-11
QUARTER TRIM PANEL................23-74
QUARTER WINDOW..................23-84
RADIATOR CROSSMEMBER............23-49
RADIATOR FAN.......................7-14
RADIATOR PRESSURE CAP..............7-19
RADIATOR...........................7-17
RADIO..............................8A-2
RAIN SENSOR CONTROL MODULE......8R-15
RAIN SENSOR.......................8R-12
REAR AXLE..........................3-12
REAR A / C CONDENSER FAN...........24-83
REAR A / C EVAPORATOR..............24-84
REAR A / C EXPANSION VALVE..........24-85
REAR BUMPER - STEP.................13-2
REAR CROSSMEMBER - TRANSMISSION . . 13-11
REAR DISCHARGE LINE...............24-88
REAR FASCIA........................13-3
REAR LATCH STRIKER................23-40
REAR LATCH........................23-40
REAR LIQUID LINE...................24-91
REAR RECEIVER / DRIER..............24-94
REAR REFRIGERANT RESERVOIR........24-95
REAR SEAT BACK SHIELD..............23-82
REAR SEAT BELT & RETRACTOR........8O-28
REAR SEAT BELT BUCKLE.............8O-30
REAR SIDE MARKER LAMP BULB.......8L-22
REAR SUCTION LINE..................24-96
REAR TURN LAMP BULB..............8L-23
REAR VIEW MIRROR.................23-75
REAR WHEEL SPEED SENSOR...........5-31
REAR WINDOW DEFOGGER GRID........8G-7
REAR WINDOW DEFOGGER RELAY.......8G-3
REAR WINDOW DEFOGGER SWITCH......8G-4
REAR...............................2-11
RECEIVER / DRIER...................24-79
RECIRCULATION DOOR ACTUATOR......24-22
REFRIGERANT LINE COUPLER..........24-98
REFRIGERANT OIL...................24-81
REFRIGERANT.......................24-80
RELAY...........................8W-97-4
REMOTE KEYLESS ENTRY
TRANSMITTER.......................8N-1
REPEATER LAMP BULB................8L-23
REPEATER LAMP UNIT................8L-24
RESTRAINTS.........................8O-2
RIGHT MOUNT.......................9-56
ROTORS............................5-20
SAFETY LATCH......................23-53
SEAL - PINION........................3-39
SEAT ADJUSTERS - FRONT.............23-81
SEAT BACK CUSHION / COVER - REAR....23-82
SEAT BACK - FRONT..................23-80
SEAT BELT SWITCH..................8O-31
SEAT BELT TENSIONER................8O-32
SEAT BELT TURNING LOOP ADJUSTER . . . 8O-33
SEAT CUSHION - FRONT...............23-80
SEAT CUSHION / COVER - REAR.........23-83
SEATBELT INDICATOR.................8J-24
SEAT - FRONT.......................23-79
SEAT - REAR........................23-81
SECURITY SYSTEM MODULE............8Q-2
SENTRY KEY REMOTE ENTRY MODULE....8Q-2
SERVO..............................8P-2
SHAFT - AXLE DUAL REAR WHEELS......3-27
SHAFT - AXLE SINGLE REAR WHEEL......3-23
SHIFT MECHANISM..................21-168
SHOCK..............................2-13
SHOES..............................5-27
SIDE CURTAIN AIRBAG................8O-35
SIDE IMPACT SENSOR................8O-39
SIDE VIEW MIRROR..................23-49
SIDE VIEW MIRROR - GLASS...........23-50
SIREN..............................8Q-4
SLIDING DOOR......................23-40
SOLENOID.........................21-171
SPARE TIRE CARRIER.................22-12
SPEAKER............................8A-2
SPEED CONTROL.....................8P-1
SPEEDOMETER......................8J-25
SPRING CLAMP PLATES.................2-8
SPRING SHACKLE.....................2-15
SPRING STOP PLATES..................2-9
SPRING
.........................2-7, 2-14
STABILIZER BAR
..................2-9, 2-15
STABILIZER LINK
.................2-10, 2-16
STABILIZER
.........................23-45
STARTER MOTOR RELAY
..............8F-35STARTER MOTOR....................8F-33
STARTING SYSTEM...................8F-28
STEERING ANGLE SENSOR..............5-32
STEERING COLUMN OPENING COVER....23-68
STEERING WHEEL.....................19-6
STEERING...........................19-1
STEPWELL SCUFF PADS...............23-75
STRUT..............................2-10
SUCTION LINE.......................24-81
SUN VISOR.........................23-76
SUPPORT PLATE......................5-23
SUPPRESSOR FILTER - REAR BLOWER
MOTOR............................24-41
SUPPRESSOR FILTER - REAR
CONDENSER FAN....................24-43
SWITCH.............................8P-3
TACHOMETER.......................8J-25
TAIL LAMP UNIT.....................8L-25
TAILPIPE............................11-3
TEMPERATURE CONTROL..............24-38
TEMPERATURE SENSOR...............24-40
TEMPERATURE SENSOR / PARK -
NEUTRAL CONTACT..................21-176
TERMINAL........................Intro.-10
THREADED HOLE REPAIR.............Intro.-6
TIE ROD END ........................19-10
TIME DELAY RELAY....................8L-35
TIMING CHAIN AND SPROCKETS.........9-72
TIMING CHAIN COVER.................9-70
TIMING CHAIN TENSIONER..............9-81
TIRES..............................22-7
TIRES / WHEELS......................22-1
TONE WHEEL........................5-32
TOP COVER.........................23-67
TOP COVER - CLUSTER................23-64
TOP COVER - TRAY...................23-65
TORQUE CONVERTER HUB SEAL.......21-184
TORQUE CONVERTER................21-178
TORQUE REFERENCES...............Intro.-9
TOWING.............................0-7
TRACTION CONTROL INDICATOR........8J-26
TRACTION CONTROL MALFUNCTION
INDICATOR.........................8J-27
TRAILER HITCH......................13-11
TRANSMISSION CONTROL MODULE......8E-6
TRANSPONDER KEY...................8Q-5
TRIM PANEL.............23-18, 23-34, 23-46
TURBOCHARGER SYSTEM..............11-3
TURBOCHARGER......................11-6
TURN SIGNAL INDICATOR..............8J-27
TURN SIGNAL RELAY.................8L-26
UNDERBODY LINES..................24-100
UPPER ROLLER ARM.................23-36
VACUUM PUMP.......................9-54
VALVE COOLER.......................25-6
VALVE SPRINGS......................9-35
VALVE STEM SEALS...................9-34
VALVE ..............................25-5
VEHICLE IDENTIFICATION NUMBER.....Intro.-1
VEHICLE THEFT SECURITY..............8Q-1
VIBRATION DAMPER...................9-53
VOLTAGE REGULATOR.................8F-24
WAIT - TO - START INDICATOR..........8J-28
WASHER FLUID INDICATOR............8J-29
WASHER FLUID LEVEL SWITCH.........8R-16
WASHER HOSES / TUBES..............8R-18
WASHER NOZZLE....................8R-18
WASHER PUMP / MOTOR..............8R-19
WASHER RESERVOIR.................8R-21
WATER IN FUEL SENSOR..............14-30
WATER PUMP........................7-20
WATER VALVE .......................24-83
WATER - IN - FUEL INDICATOR..........8J-29
WHEEL ALIGNMENT...................2-17
WHEELS...........................22-13
WINDOW MOTOR.....................8N-5
WINDOW REGULATOR - MANUAL........23-21
WINDOW REGULATOR - POWER........23-20
WINDSHIELD........................23-85
WIPER ARM........................8R-23
WIPER BLADE.......................8R-26
WIPER LINKAGE.....................8R-28
WIPER MOTOR......................8R-31
WIPER RELAY.......................8R-34
WIPERS/WASHERS....................8R-2
WIRING DIAGRAM INFORMATION......Intro.-1
YAW RATE SENSOR...................5-35
2 INDEXVA
Description Group-Page Description Group-Page Description Group-Page

TABLE OF CONTENTS - Continued
BACKUP LAMP CKT SHORT TO VOLTAGE OR OPEN........................15
BACKUP LAMP SUPPLY CIRCUIT OPEN...................................16
CAN BUS CIRCUIT......................................................17
INCORRECT CAN MESSAGE FROM ABS...................................18
INTERNAL CONTROLLER................................................19
LR WHEEL SPIN CAN MESSAGE NOT VALID...............................20
OVER VOLTAGE........................................................21
RR WHEEL SPIN CAN MESSAGE NOT VALID...............................22
UNDER VOLTAGE......................................................23
TRANSMISSION - NAG1
1-2/4-5 SOLENOID CIRCUIT..............................................24
1-2/4-5 SOLENOID CIRCUIT SHORT TO GROUND...........................24
2-3 SOLENOID CIRCUIT.................................................27
2-3 SOLENOID CIRCUIT SHORT TO GROUND..............................27
3-4 SOLENOID CIRCUIT.................................................30
3-4 SOLENOID CIRCUIT SHORT TO GROUND..............................30
ABS BRAKE MESSAGE..................................................33
ABS CAN MESSAGE INCORRECT.........................................35
ABS CAN MESSAGE MISSING............................................36
ABS LF SENSOR MESSAGE..............................................38
ABS LR SENSOR MESSAGE.............................................40
ABS RF SENSOR MESSAGE.............................................42
ABS RR SENSOR MESSAGE.............................................44
ACCEL PEDAL SENSOR CAN MESSAGE INCORRECT.......................46
CAN BUS CIRCUIT......................................................48
CAN MESSAGE FROM ECM FROM SLA....................................53
CONTROL MODULE TCM IS NOT CODED..................................55
ENGINE CAN MESSAGE INCORRECT.....................................56
ENGINE CAN MESSAGE MISSING........................................58
ENGINE OVERSPEED...................................................60
ENGINE RPM MESSAGE.................................................62
ENGINE TEMP MESSAGE................................................64
ENGINE TORQUE MESSAGE INCORRECT.................................66
ENGINE TORQUE REDUCTION...........................................68
IC CAN MESSAGE INCORRECT..........................................70
IC/ATC CAN MESSAGE MISSING..........................................72
IMPROPER GEAR......................................................74
IMPROPER RATIO......................................................76
INPUT SENSOR MISMATCH..............................................78
INPUT SENSOR OVERSPEED............................................80
INTERNAL CONTROLLER................................................82
INVALID CONTROL MODULE VERSION....................................83
MODULATING PRESSURE SOLENOID CIRCUIT.............................84
N2 INPUT SPEED SENSOR CIRCUIT......................................87
N3 INPUT SPEED SENSOR CIRCUIT......................................91
SENSOR SUPPLY VOLTAGE..............................................95
SHIFT LEVER POSITION INVALID.........................................97
SHIFT PRESSURE SOLENOID CIRCUIT....................................99
SLA CAN MESSAGE INCORRECT........................................102
SOLENOID SUPPLY VOLTAGE...........................................103
SOLENOID SUPPLY/WATCHDOG.........................................105
SYSTEM OVERVOLTAGE...............................................107
ii

1.0 INTRODUCTION
The procedures contained in this manual include
all of the specifications, instructions, and graphics
needed to diagnose NAG1 Electronic Automatic
Transmission and Shift Lever Assembly problems.
The diagnostics in this manual are based on the
failure condition or symptom being present at the
time of diagnosis.
When repairs are required, refer to the appropri-
ate volume of the service information for the proper
removal and repair procedure.
READ THIS MANUAL BEFORE TRYING TO
DIAGNOSE A VEHICLE TROUBLE CODE.
Diagnostic procedures change every year. New
diagnostic systems may be added and/or carryover
systems may be enhanced. It is recommended that
you review the entire manual to become familiar
with all new and changed diagnostic procedures.
1.1 SYSTEM COVERAGE
This diagnostic procedures manual covers all
Sprinter (VA) equipped with a NAG1 Automatic
Transmission.
1.2 SIX -STEP TROUBLESHOOTING
PROCEDURE
Diagnosis of the NAG1 electronic transmission is
done in six basic steps:
Verification of complaint
Verification of any related symptoms
Symptom analysis
Problem isolation
Repair of isolated problem
Verification of proper operation
2.0 IDENTIFICATION OF
SYSTEM
The NAG1 Transmission family can be identified
by the presence of a 13 pin electrical connector, with
a bayonet lock on the right hand side of the trans-
mission. The connector is oriented horizontally.
3.0 SYSTEM DESCRIPTION AND
FUNCTIONAL OPERATION
3.1 GENERAL DESCRIPTION
The NAG1 electronic transmission is an electron-
ically controlled five speed transmission with a
controlled slip torque converter. The NAG1 elec-tronic transmission is a conventional transmission
in that it uses hydraulically applied clutches to shift
a planetary gear train. However, the electronic
control system replaces many of the mechanical and
hydraulic components used in conventional trans-
mission valve bodies.
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 electronic
control system enables precise adaptation of pres-
sures to the respective operating conditions and to
the engine output during a shift phase, which
results in a significant improvement in shift qual-
ity.
3.2 FUNCTIONAL OPERATION
The NAG1 electronic transmission has a fully
adaptive control system. The system performs its
functions based on continuous real-time sensor and
switch feedback information. In addition the TCM
receives information from the Shift Lever Assembly,
ECM (engine management) and ABS (chassis sys-
tems) controllers over the CAN bus. The CAN bus is
a high speed communication bus that allows real
time control capability between various controllers.
Most messages are sent every 20 milliseconds, this
means critical information can be shared between
the Transmission, Shifter, Engine and ABS control-
lers. The CAN bus is a two wire bus with aCAN C
Bus (+) circuitand aCAN C Bus (-) circuit. The
CAN bus uses a twisted pair of wires in the harness
to reduce the potential of radio and noise interfer-
ence. The CAN bus also uses a 120 ohm terminating
resistor in both the ECM and Sentry Key Remote
Entry Module (SKREEM) modules. The module
terminating resistance is measured across both
CAN bus circuits at the ECM or SKREEM module.
The control system automatically adapts to
changes in engine performance, vehicle speed, and
transmission temperature variations to provide
consistent shift quality. The control system ensures
that clutch operation during upshifting and down-
shifting is more responsive without increased
harshness. The TCM controls the actuation of sole-
noid valves for modulating shift pressure and gear
change. The required pressure level is calculated
from the load condition, engine speed. Power for the
transmission system is supplied through the Trans-
mission Relay. The TCM is located in the under the
drivers seat of the vehicle.
The Transmission Control Module (TCM) contin-
uously checks for electrical problems, mechanical
problems, and some hydraulic problems. When a
problem is sensed, the TCM stores a diagnostic
trouble code (DTC). Some of these codes cause the
transmission to go into9limp-in9or9default9mode.
1
GENERAL INFORMATION

3-4 solenoid -The 3-4 solenoid is activated when
the TCM determines that the transmission must
shift into or out of 4th gear. The solenoid is only
activated during the shifting of the transmission.
When the solenoid is activated, hydraulic pressure
is applied to the proper shift elements in the trans-
mission to allow the desired shift. Once the shift is
completed, the solenoid is turned off.
TCC solenoid -The TCC solenoid is activated
when the TCM determines that the Torque con-
verter clutch should be activated. The TCC clutch is
a variable slip torque clutch that allows control of
torque converter slip from 5% to 95.5% of full TCC
engagement. The clutch is controlled by the TCC
solenoid which is pulse width modulated (PWM) to
provide the desired amount of slip.
Shift Pressure Solenoid -The Shift Pressure
Solenoid is activated when the TCM determines
that a transmission shift is required. The solenoid
is PWM controller to allow the proper amount of
hydraulic pressure to the shift elements. The sole-
noid is only activated during the shifting of the
transmission. When the solenoid is activated, hy-
draulic pressure is removed from the proper shift
elements to allow the desired shift. Once the shift is
completed, the solenoid is turned off.
Modulation pressure solenoid -The modulation
pressure is always active. The solenoid is pulse
width modulated (PWM) controlled and is used to
modulate the hydraulic system pressure to the
desired pressure.
3.2.4 TRANSMISSION COMPONENT
DESCRIPTIONS
Shift Assembly
The Shift Lever Selector transmits all selector lever
positions, as well as selected shift ranges to the
TCM over the CAN Bus. At the same time, the
selector lever positions P, R, N, and D are transmit-
ted by a cable to the selector lever shaft in the
transmission.
Brake shift inter-lock
To prevent unauthorized shifting out of the park
position, the Selector lever is locked in the Park
position until the ignition key is turned to the run
position and the brake pedal is pressed. This will
allow the driver to shift out of the park position.
Reverse Lamp Output
The Reverse Light Switch is integrated into the
shifter module and controls the reverse lights.
Reverse Inhibitor
The Shift Lever Assembly constantly monitors ABS
wheel speed to prevents an inadvertent selection of
reverse at speeds above approximately 6.4 Km/h(4MPH). The Reverse inhibitor is part of the Shift
Lever Assembly and is controlled by the Shift Lever
Assembly module.
Trans temp sensor - P/N Switch circuit
The TCM will detect the selector lever in park and
neutral positions. The TCM does this by monitoring
the Transmission temperature sensor signal along
with the shifter position signals. The P/N switch
contact is operated by a cam located in the trans-
mission which, opens a reed contact switch that is
wired in series with the transmission temperature
sensor. When the P/N contact switch is opened in
park and neutral, the TCM senses a high transmis-
sion temperature. Confirming the P/N switch sta-
tus. Note: In park or neutral, the TCM uses engine
temperature (to avoid setting a DTC). The TCM
sends a hardwired signal to the ECM that will allow
the ECM controlled start circuit to engage in P or N
only. The TCM also sends a P/N bus message to the
ECM to confirm the P/N switch status.
The Normal Transmission Temperature Sensor
resistance is between 500.0 and 2500.0 ohms.
The normal voltage limits for the transmis-
sion temperature sensor, are between 0.5 and
3.0 volts.
Input Speed Sensors
The NAG1 transmission has two input speed sen-
sors N2 and N3, both speed sensors are located on
the valve body and report DTC's for the input speed
sensors errors. The speed sensors are Hall Effect
speed sensors that are used by the TCM to calculate
the transmissions input speed. Since the input
speed could not 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. The input sensors N2 and
N3 will report the same input speed in gears 2nd,
3rd or 4th. If the N2 and N3 input speed signals are
not the same in these gears then there is an issue
with the transmission and the DTC Input Sensors
Mismatch will be set.
The N3 input speed is not reported in1st and 5th
gears. The N2 sensor is not reported in Reverse.
The Input Speed Sensor Overspeed is a rationality
check that is intended to indicate a major transmis-
sion failure and will cause a loss of drive (place the
transmission in Neutral)
Output Speed Sensor (ABS signal)
The NAG1 transmission does not have an output
shaft speed sensor. The TCM uses the ABS (An-
tilock Brake System) Wheel Speed sensor informa-
tion, it receives over the CAN bus, to calculate the
transmissions output shaft speed. The TCM moni-
tors the ABS system for functionality and reports
ABS speed sensor and communication DTCs, which
will affect proper transmission operation.
3
GENERAL INFORMATION

Emergency running function
If DTCs occur, safe-driving conditions must be re-
tained but full functionality of the transmission will
be limited to avoid damaging the automatic trans-
mission. In the event of certain DTCs the TCM
switches to emergency running. The TCM will store
the appropriate DTC codes and solenoids will be
de-energized (turned off)
The transmission effects will be:
²The last gear shifted remains in that position
²The modulating pressure and shift pressure in-
crease to maximum value
²The torque converter clutch is disengaged
(turned off)
Shifting manually after a DTC detection
NOTE: The vehicle can still be shifted
manually to 2nd or reverse gear.
To accomplish these shifts you must
Stop the vehicle
Turn the ignition off
Start the engine
Place the selector lever into D for 2nd gear
Place the selector lever into R for reverse gear
The emergency running function is retained until
the DTC is eliminated or the stored DTC code is
erased.
Stored (Intermittent) DTCs can be reset by cy-
cling the ignition switch
3.3.3 TROUBLE CODE ERASURE
Diagnostic Trouble Codes can be erased in two
ways. The first is to erase the DTC with the DRBIII
or scan tool. The second is if the DTC is no longer
present, the DTC is reset by the TCM (after an
ignition cycle), which will place the DTC in an
intermittent status (Stored DTC).
When there are no diagnostic trouble codes
stored in memory, the DRBIIItwill display
(NO DTC's DETECTED(
3.4 USING THE DRBIIIT
Refer to the DRBIIItuser's guide for instructions
and assistance with reading trouble codes, erasing
trouble codes, and other DRBIIItfunctions.
3.5 DRBIIITERROR MESSAGES
Under normal operation, the DRBIIItwill display
one of only two error messages:
± User-Requested WARM Boot
± User-Requested COLD Boot
If the DRBIIItshould display any other error
message, record the entire display and call the
S.T.A.R. Center.
3.5.1 DRBIIITDOES NOT POWER UP
(BLANK SCREEN)
If the LED's do not light or no sound is emitted at
start up, check for loose cable connections or a bad
cable. Check the vehicle battery voltage. A mini-
mum of 11 volts is required to adequately power the
DRBIIIt.
If all connections are proper between the DRBI-
IItand the vehicle or other devices, and the vehicle
battery is fully charged, an inoperative DRBIIIt
may be the result of faulty cable or vehicle wiring.
For a blank screen, refer to the appropriate Body
Diagnostic manual.
3.5.2 DISPLAY IS NOT VISIBLE
Low temperatures will affect the visibility of the
display. Adjust the contrast to compensate for this
condition.
4.0 DISCLAIMERS, SAFETY,
AND WARNINGS
4.1 DISCLAIMERS
All information, illustrations, and specifications
contained in this manual are based on the latest
5
GENERAL INFORMATION