automatic transmission MERCEDES-BENZ SPRINTER 2006 Service Manual

SYSTEM EMPTY
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible (approximately 28 in Hg.)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM EVACUATE). Determine if the
system holds a vacuum for 15 minutes. If vacuum is
held, a leak is probably not present. If system will
not maintain vacuum level, proceed to Step 2.
(2) Prepare and dispense 0.284 kilograms (10
ounces) of R-134a refrigerant into the evacuated
refrigerant system (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM CHARGE) and
proceed to Step 1 of the System Low procedure.
SYSTEM LOW
(1) Position the vehicle in a wind free work area.
This will aid in detecting small leaks.
(2) Operate the heating-A/C system with the
engine at idle under the following conditions for at
least five minutes.
²Doors or windows open
²Transmission in Park
²A/C-heater controls set to outside air, full cool,
panel mode, high blower and with A/C compressor
engaged
CAUTION: A leak detector only designed for R-12
refrigerant will not detect leaks in a R-134a refriger-
ant system.
(3) Shut the vehicle Off and wait 2-7 minutes.
Then use an electronic leak detector that is designed
to detect R-134a refrigerant and search for leaks. Fit-
tings, lines or components that appear to be oily usu-
ally indicate a refrigerant leak. To inspect the A/C
evaporator for leaks, insert the leak detector probe
into the drain tube opening or an air outlet. A dye for
R-134a is available to aid in leak detection. Use only
DaimlerChrysler approved refrigerant dye.
STANDARD PROCEDURE
REFRIGERANT SYSTEM SERVICE EQUIPMENT
WARNING: Eye protection must be worn when ser-
vicing an A/C refrigerant system. Turn off (rotate
clockwise) all valves on the equipment being used,
before connecting to or disconnecting from the
refrigerant system. Failure to observe these warn-
ings may result in possible personal injury.
WARNING: Refer to the applicable warnings and
cautions for this system before performing the fol-
lowing operation (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNINGS) and (Referto 24 - HEATING & AIR CONDITIONING/PLUMBING -
CAUTIONS). Failure to follow the warnings and cau-
tions could result in possible personal injury or
death.
When servicing the air conditioning system, a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 must be used.
Contact an automotive service equipment supplier for
refrigerant recovery/recycling/charging equipment.
Refer to the operating instructions supplied by the
equipment manufacturer for proper care and use of
this equipment.
A manifold gauge set may be needed with some
recovery/recycling/charging equipment (Fig. 1). The
service hoses on the gauge set being used should
have manual (turn wheel), or automatic back-flow
valves at the service port connector ends. This will
prevent refrigerant from being released into the
atmosphere.
MANIFOLD GAUGE SET CONNECTIONS
CAUTION: Do not use an R-12 manifold gauge set
on an R-134a system. The refrigerants are not com-
patible and system damage will result.
Fig. 1 Manifold Gauge Set - Typical
1 - HIGH PRESSURE GAUGE
2 - VALVE
3 - VACUUM/REFRIGERANT HOSE (YELLOW W/ BLACK
STRIPE)
4 - HIGH PRESSURE HOSE (RED W/ BLACK STRIPE)
5 - LOW PRESSURE HOSE (BLUE W/ BLACK STRIPE)
6 - VALVE
7 - LOW PRESSURE GAUGE
VAPLUMBING 24 - 63

INDEX
ABS INDICATOR.......................8J-9ACCELERATOR PEDAL POSITION SENSOR. . . 14-32
ACCESSORY SWITCH BEZEL............23-56
ADR INDICATOR.....................8J-10
AIR CLEANER ELEMENT................9-21
AIR CLEANER HOUSING................9-21
AIR FILTER ....................24-45, 24-58
AIR OUTLET TEMPERATURE SENSOR....24-16
AIR OUTLETS.......................24-45
AIRBAG CONTROL MODULE.............8O-8
AIRBAG INDICATOR...................8J-11
ALB CONTROLLER....................5-16
ALB LEVER..........................5-16
AMBIENT TEMPERATURE INDICATOR.....8J-11
AMBIENT TEMPERATURE SENSOR.......24-17
ANTENNA BODY & CABLE..............8A-1
ARMREST..........................23-79
ASH RECEIVER......................23-57
ASH RECEIVER / CIGAR LIGHTER LAMP
UNIT..............................8L-30
ASSIST HANDLE.....................23-71
AUDIO..............................8A-1
AUTOMATIC TRANSMISSION NAG1 -
SERVICE INFORMATION................21-3
A - PILLAR TRIM.....................23-70
A / C CLUTCH RELAY.................24-24
A / C COMPRESSOR CLUTCH COIL.......24-12
A / C COMPRESSOR CLUTCH............24-8
A / C COMPRESSOR..................24-66
A / C CONDENSER COVER.............24-52
A / C CONDENSER FAN RELAY..........24-26
A / C CONDENSER HOUSING...........24-52
A / C CONDENSER....................24-69
A / C CONTROL MODULE..............24-28
A / C DISCHARGE LINE................24-71
A / C EVAPORATOR COVER.............24-55
A / C EVAPORATOR HOUSING...........24-55
A / C EVAPORATOR...................24-72
A / C EXPANSION VALVE...............24-73
A / C HEATER CONTROL...............24-12
A / C HIGH PRESSURE SWITCH.........24-30
A / C LOW PRESSURE SWITCH.........24-32
A / C PRESSURE TRANSDUCER.........24-14
BACKLITE - BULKHEAD TRIM PANEL.....23-84
BACKUP LAMP BULB..................8L-5
BASECOAT / CLEARCOAT FINISH........23-77
BATTERY CABLES....................8F-14
BATTERY HOLDDOWN.................8F-13
BATTERY SYSTEM.....................8F-1
BATTERY TRAY......................8F-16
BATTERY............................8F-6
BEARINGS - DIFFERENTIAL CASE.........3-38
BEARING / SEAL - AXLE HUB............3-28
BEARING / SEAL - AXLE................3-24
BELT TENSIONERS.....................7-5
BLOWER MOTOR RELAY...............24-33
BLOWER MOTOR RESISTOR............24-17
BLOWER MOTOR SWITCH........24-19, 24-35
BLOWER MOTOR...............24-47, 24-58
BODY...............................23-1
BOOST PRESSURE SENSOR............14-33
BRAKE INDICATOR...................8J-12
BRAKE LAMP SWITCH.................8L-6
BRAKE LINES.........................5-8
BRAKE PADS / SHOES...................5-8
BRAKE WEAR INDICATOR..............8J-13
BRAKES - ABS........................5-30
BRAKES - BASE........................5-2
BRAKE / PARK LAMP BULB.............8L-7
BULKHEAD TRIM PANEL...............23-72
BUMPERS...........................13-1
BUSHINGS............................2-3
B - PILLAR TRIM.....................23-71
CABIN HEATER.....................24-104
CABLE TENSIONER....................5-24
CABLE..............................8P-2
CABLES.............................5-24
CAMSHAFT POSITION SENSOR..........14-33
CAMSHAFT(S)........................9-28
CARGO LAMP SWITCH................8L-31
CARGO / DOME LAMP BULB............8L-30
CARGO / DOME LAMP UNIT............8L-31
CARPETS AND FLOOR MATS...........23-72
CATALYTIC CONVERTER
................11-3
CENTER BEARING
......................3-9
CENTER HIGH MOUNTED STOP LAMP BULB. . . 8L-8CENTER HIGH MOUNTED STOP LAMP UN.....8L-8
CENTER ROLLER ARM
................23-36CENTER TRACK......................23-37
CENTRAL TIMER MODULE..............8E-1
CHARGE AIR COOLER AND PLUMBING....11-4
CHARGING INDICATOR................8J-14
CHARGING SYSTEM..................8F-17
CHECK VALVE.......................8R-11
CHECK.......................23-13, 23-23
CHIME / BUZZER......................8B-1
CIGAR LIGHTER OUTLET............8W-97-1
CIRCUIT BREAKER.................8W-97-2
CLEARANCE LAMP BULB...............8L-9
CLEARANCE LAMP UNIT................8L-9
CLOCK.............................8J-14
CLOCKSPRING......................8O-12
CLUSTER BEZEL.....................23-55
COLUMN............................19-4
CONNECTOR.......................Intro.-9
CONNECTOR/GROUND/SPLICE
LOCATION........................8W-91-1
CONTROLLER ANTILOCK BRAKE.........8E-3
COOLANT LEVEL SENSOR...............7-13
COOLANT LOW INDICATOR.............8J-15
COOLANT............................7-9
COOLING.............................7-1
COWL TRIM........................23-73
CRANKCASE VENTILATION BREATHER......25-2
CRANKCASE VENTILATION HEATER.......25-1
CRANKSHAFT OIL SEAL - FRONT.........9-42
CRANKSHAFT OIL SEAL - REAR..........9-41
CRANKSHAFT POSITION SENSOR........14-35
CRANKSHAFT........................9-39
CUP HOLDER........................23-57
CYLINDER HEAD COVER(S).............9-33
CYLINDER HEAD......................9-22
DAYTIME RUNNING LAMP RELAY.......8L-10
DEFROSTER DUCTS..................24-47
DIFFERENTIAL........................3-31
DIODE............................Intro.-9
DISC BRAKE CALIPER ADAPTER.........5-14
DISC BRAKE CALIPERS.................5-11
DOME LAMP / INTRUSION SENSOR
BULB..............................8L-33
DOME LAMP / INTRUSION SENSOR......8L-33
DOME / READING LAMP BULB..........8L-32
DOME / READING LAMP UNIT..........8L-32
DOOR GLASS............23-15, 23-30, 23-46
DOOR JAMB SWITCH.................8L-34
DOOR LOCK MOTOR...................8N-1
DOOR OPENING SEALS................23-90
DOOR........................23-14, 23-23
DRIVE BELTS..........................7-5
DRIVER AIRBAG.....................8O-16
DRIVER HEATED SEAT SWITCH.........8G-11
D - PILLAR TRIM.....................23-73
ELECTRIC COOLANT PUMP.............24-75
ELECTRICAL.........................5-30
ELECTROHYDRAULIC UNIT............21-105
ENGINE BLOCK HEATER................7-14
ENGINE BLOCK.......................9-37
ENGINE CONTROL MODULE.............8E-3
ENGINE COOLANT TEMP SENSOR........7-15
ENGINE COOLANT THERMOSTAT.........7-16
ENGINE CRADLE CROSSMEMBER........13-8
ENGINE TEMPERATURE GAUGE.........8J-15
ENGINE..............................9-2
ENTRY / EXIT LAMP BULB.............8L-34
ENTRY / EXIT LAMP UNIT..............8L-35
ESP INDICATOR......................8J-16
EVAPORATOR TEMPERATURE
SENSOR......................24-19, 24-37
EXHAUST GAS RECIRCULATION..........25-4
EXHAUST MANIFOLD..................9-68
EXHAUST PIPE.......................11-3
EXHAUST SYSTEM....................11-1
EXHAUST TUBE.....................24-105
EXTERIOR HANDLE.......23-16, 23-31, 23-35
FAN DRIVE VISCOUS CLUTCH...........7-17
FASTENER IDENTIFICATION...........Intro.-3
FASTENER USAGE...................Intro.-6
FINESSE SANDING / BUFFING & POLISH . . 23-78
FLOOR DISTRIBUTION DUCTS..........24-47
FLUID AND FILTER..................21-131
FLUID CAPACITIES.....................0-5
FLUID COOLER TUBE
.................19-13
FLUID FILL / CHECK LOCATIONS
..........0-5
FLUID RESERVOIR
....................5-15
FLUID TYPES
..........................0-1
FLYWHEEL
...........................9-43FOG LAMP BULB.....................8L-10
FOG LAMP RELAY....................8L-11
FOG LAMP SWITCH...................8L-12
FRAME..............................13-3
FREEWHEELING CLUTCH.............21-135
FRONT BUMPER - STEPS...............13-2
FRONT DOOR INNER BELT
WEATHERSTRIP.....................23-90
FRONT DOOR OUTER BELT
WEATHERSTRIP.....................23-90
FRONT FASCIA.......................13-2
FRONT LAMP UNIT...................8L-13
FRONT POSITION LAMP BULB..........8L-14
FRONT SEAT BELT & RETRACTOR.......8O-20
FRONT SEAT BELT BUCKLE............8O-23
FRONT TURN / PARK / SIDE MARKER
LAMP BULB.........................8L-15
FRONT WHEEL SPEED SENSOR..........5-31
FRONT...............................2-1
FUEL DELIVERY.......................14-6
FUEL DOSING PUMP.................24-106
FUEL DRAIN TUBES..................14-10
FUEL FILL DOOR.....................23-48
FUEL FILTER CLOGGED INDICATOR......8J-17
FUEL FILTER........................14-10
FUEL GAUGE........................8J-17
FUEL INJECTOR.......................14-35
FUEL LEVEL SENDING UNIT / SENSOR....14-28
FUEL LINE.........................24-107
FUEL LINES.........................14-11
FUEL PRESSURE SENSOR.............14-39
FUEL PRESSURE SOLENOID............14-40
FUEL PUMP MODULE.................14-18
FUEL PUMP.........................14-13
FUEL QUANTITY CONTROL VALVE.......14-21
FUEL RAIL PRESSURE SENSOR.........14-12
FUEL RAIL..........................14-22
FUEL SYSTEM........................14-1
FUEL TANK.........................14-23
FUEL TEMPERATURE SENSOR..........14-42
FUSE BLOCK #1...................8W-97-2
FUSE BLOCK #2...................8W-97-3
GAP AND FLUSH.....................23-91
GEAR SELECTOR INDICATOR...........8J-18
GEAR...............................19-7
GEARSHIFT CABLE..................21-138
GEAR - PINION / RING.................3-41
GENERATOR DECOUPLER PULLEY.......8F-19
GENERATOR........................8F-18
GLOVE BOX.........................23-58
GLOW PLUG RELAY....................8I-1
GLOW PLUG..........................8I-1
GRILLE............................23-48
HCU (HYDRAULIC CONTROL UNIT).......5-36
HEADLAMP LEVELING MOTOR..........8L-16
HEADLAMP LEVELING SWITCH.........8L-17
HEADLINER.........................23-73
HEADREST..........................23-79
HEATED GLASS.......................8G-1
HEATED MIRRORS....................8G-9
HEATED SEAT ELEMENT...............8G-12
HEATED SEAT RELAY.................8G-12
HEATED SEAT SENSOR................8G-13
HEATED SEATS ......................8G-10
HEATER CORE.......................24-76
HEATER UNIT......................24-110
HEATING & AIR CONDITIONING..........24-1
HIGH BEAM HEADLAMP BULB..........8L-18
HIGH BEAM INDICATOR...............8J-19
HINGE..................23-17, 23-32, 23-51
HOISTING............................0-5
HOLDING CLUTCH B1................21-143
HOLDING CLUTCH B2................21-148
HOLDING CLUTCHES.................21-141
HOOD.............................23-51
HORN SWITCH.......................8H-1
HORN..............................8H-1
HOSES.............................19-14
HUB / BEARING........................2-4
HVAC HOUSING......................24-48
HYDRAULIC / MECHANICAL..............5-5
IGNITION CONTROL....................8I-1
INLET HOSE........................24-111
INPUT CLUTCH K1
...................21-92
INPUT CLUTCH K2
...................21-97
INPUT CLUTCH K3
..................21-102
INPUT CLUTCHES
....................21-90
INPUT SPEED SENSORS
..............21-153
VAINDEX 1
Description Group-Page Description Group-Page Description Group-Page

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

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

Symptom:
IC/ATC CAN MESSAGE MISSING
POSSIBLE CAUSES
CAN BUS CIRCUIT DTC PRESENT
AUTOMATIC TEMP CONTROL DTCS PRESENT
INSTRUMENT CLUSTER DTCS PRESENT
OPEN CAN BUS CIRCUITS AT INSTRUMENT CLUSTER
OPEN CAN BUS CIRCUITS AUTOMATIC TEMP CONTROL
AUTOMATIC TEMP CONTROL
INSTRUMENT CLUSTER
TEST ACTION APPLICABILITY
1NOTE: Low fluid level can be the cause of many transmission problems. If
the fluid level is low locate and repair the leak then check and adjust the
fluid level per the service information.
NOTE: Always perform diagnostics with a fully charged battery to avoid
false symptoms.
With the DRBIIIt, read the engine DTCs. Check and repair all engine DTCs prior to
performing transmission symptom diagnostics.
With the DRBIIIt, read and record all Transmission DTCs.
NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal
connections can set DTCs.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
Repair as necessary.
Most DTCs set on start up but some must be set by driving the vehicle such that all
diagnostic monitors have run.
Note: Verify flash level of transmission controller. Some problems are
corrected by software upgrades to the transmission controller.
NOTE: Check for any Technical Service Bulletins that may apply.
Perform this procedure prior to Symptom diagnosis.All
Continue
Go To 2
2 Ignition on, engine not running.
With the DRBIIIt, read Transmission DTCs.
NOTE: If the DTC, CAN BUS CIRCUIT, is present, perform diagnostics on
that symptom first.
Is the DTC, CAN BUS CIRCUIT, present?All
Ye s!Refer to the Transmission category and perform the appropriate
symptom.
No!Go To 3
3NOTE: NOTE: If vehicle is equipped with Air Conditioning diagnose the ATC
system first.
Is the vehicle equipped with air conditioning?All
Ye s!Go To 4
No!Go To 6
72
TRANSMISSION - NAG1

TEST ACTION APPLICABILITY
4 Ignition on, engine not running.
With the DRBIIIt, read Automatic Temp Control DTCs.
Are there any ATC DTCs present?All
Ye s!Refer to the Heating and A/C category and perform the appropri-
ate symptom.
No!Go To 5
5 Turn the ignition off to the lock position.
Disconnect the ATC harness connector.
Measure the resistance between the CAN Bus (+) circuit and the CAN Bus (-) circuit
in the ATC harness connector.
Is the resistance 60 ohms,   3.0 ohms?All
Ye s!Replace the Automatic Temp Control per the service information.
No!Repair the CAN C Bus (+) or the CAN C Bus (-) circuit for an open.
6NOTE: If vehicle is equipped with Air Conditioning diagnose the ATC
system first.
Ignition on, engine not running.
With the DRBIIIt, read Instrument Cluster or Automatic Temp Control DTCs.
Are there any Instrument Cluster DTCs present?All
Ye s!Refer to the INSTRUMENT CLUSTER category and perform the
appropriate symptom.
No!Go To 7
7 Turn the ignition off to the lock position.
Disconnect the Instrument Cluster C1 harness connector.
Measure the resistance between the CAN Bus (+) circuit and the CAN Bus (-) circuit
in the Instrument Cluster harness connector.
Is the resistance 60 ohms,   3.0 ohms?All
Ye s!Replace the Instrument Cluster per the service information.
No!Repair the CAN C Bus (+) or the CAN C Bus (-) circuit for an open.
73
TRANSMISSION - NAG1
IC/ATC CAN MESSAGE MISSING ÐContinued