display CHRYSLER VOYAGER 2001 Service Manual

OPERATION
The Compass Mini-Trip Computer (CMTC), Com-
pass Temperature (CT) module in the overhead con-
sole has buttons used to select various functions. The
CMTC, CT selector buttons will not operate until the
ignition is in the RUN position.
When the ignition switch is first turned to the
RUN position the CMTC, CT display;
²Blanks momentarily
²
All segments of the VFD will light for one second
²Blanks momentarily
²Returns to the last mode setting selected before
the ignition was last switched OFF.
DIAGNOSIS & TESTING - COMPASS MINI-TRIP
COMPUTER
Compass Mini-Trip Computer (CMTC) and Com-
pass Temperature (CT) data is obtained from the
Body Control Module (BCM) on the J1850 Data Bus
circuit. The CMTC and CT will display dashes (- -)
for any of the screens it did not receive the bus mes-
sages. The label corresponding to the missing infor-
mation will be lit. If no compass mini-trip computer
data is displayed, check the J1850 Data Bus circuit
communications and the BCM. If the brightness level
is improper check the J1850 Data Bus circuit.
The DRB IIItis recommended for checking the
J1850 Data Bus circuit and the BCM. Perform the
CMTC, CT self diagnosis before replacing the CMTC
or CT module.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove overhead console. Refer to Overhead
Console Removal and Installation in this section(Re-
fer to 8 - ELECTRICAL/OVERHEAD CONSOLE -
REMOVAL) .
(3) Remove the screws holding Compass Mini-Trip
Computer module in the overhead console.
(4) Remove CMTC module from console assembly.
INSTALLATION
(1) Position the compass mini-trip computer mod-
ule in the overhead console.
(2) Install the ten screws holding the compass
mini-trip computer module in the overhead console.
(3) Install the overhead console. Refer to Overhead
Console Removal and Installation in this section.
(4) Connect the battery negative cable.
NOTE: If a new module has been installed, the com-
pass will have to be calibrated and the variance set.
Refer to Compass Variation Adjustment and Com-
pass Calibration in the Service Procedures section
of this group for the procedures.
UNIVERSAL TRANSMITTER
DESCRIPTION
On some RS models a Homelinkttransceiver is
standard factory-installed equipment. The Homelinkt
transceiver is integral to the Electronic Vehicle Infor-
mation Center (EVIC) and the Compass Mini-Trip
Computer (CMTC), which is located in the overhead
console. The only visible component of the Homelinkt
are the three transmitter push buttons centered
between the modules push buttons located just rear-
ward of the display screen in the overhead console.
The three Homelinkttransmitter push buttons are
identified with one, two or three light indicators so
that they be easily identified by sight or by feel.
Each of the three Homelinkttransmitter push but-
tons controls an independent radio transmitter chan-
nel. Each of these three channels can be trained to
transmit a different radio frequency signal for the
remote operation of garage door openers, motorized
gate openers, home or office lighting, security sys-
tems or just about any other device that can be
equipped with a radio receiver in the 286 to 399
MegaHertz (MHz) frequency range for remote opera-
tion. The Homelinktis capable of operating systems
using either rolling code or non-rolling code technol-
ogy.
The electronics module displays messages and a
small house-shaped icon with one, two or three dots
corresponding to the three transmitter buttons to
indicate the status of the Homelinkt. The EVIC mes-
sages are:
²Cleared Channels- Indicates that all of the
transmitter codes stored in the Homelinkthave been
successfully cleared.
²Training- Indicates that the Homelinktis in
its transmitter learning mode.
²Trained- Indicates that the Homelinkthas
successfully acquired a new transmitter code.
²Transmit- Indicates that a trained Homelinkt
transmitter button has been depressed and that the
Homelinktis transmitting.
The Homelinktcannot be repaired, and is avail-
able for service only as a unit with the EVIC or
CMTC modules. If any of these components is faulty
or damaged, the complete EVIC or CMTC module
must be replaced.
OPERATION
The Homelinktoperates on a non-switched source
of battery current so the unit will remain functional,
regardless of the ignition switch position. For more
information on the features, programming procedures
and operation of the Homelinkt, see the owner's
manual in the vehicle glove box.
8M - 10 OVERHEAD CONSOLERS
COMPASS/MINI-TRIP COMPUTER (Continued)

DIAGNOSIS & TESTING - HOMELINKT
If the Homelinktis inoperative, but the Electronic
Vehicle Information Center (EVIC) or Compass Mini-
Trip Computer is operating normally, see the owner's
manual in the vehicle glove box for instructions on
training the Homelinkt. Retrain the Homelinktwith
a known good transmitter as instructed in the own-
er's manual and test the Homelinktoperation again.
If the unit is still inoperative, replace the faulty
Homelinktand EVIC/CMTC module as a unit. If
both the Homelinktand the EVIC/CMTC module are
inoperative, refer toOverhead Console Diagnosis
and Testingearlier in this group for further diagno-
sis. For complete circuit diagrams, refer toOver-
head Consolein Wiring Diagrams.
AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the over-
head console through ambient temperature messages
received from the Front Control Module (FCM) over
the Programmable Communications Interface (PCI)
J1850 data bus circuit. The FCM receives a hard
wired input from the ambient temperature sensor.
The ambient temperature sensor is a variable resis-
tor mounted to a bracket that is secured with a screw
to the right side of the headlamp mounting module
grille opening, behind the radiator grille and in front
of the engine compartment.
Refer toFront Control Modulein Electronic
Control Modules. For complete circuit diagrams, refer
to the appropriate wiring information. The ambient
temperature sensor cannot be adjusted or repaired
and, if faulty or damaged, it must be replaced.
OPERATION
The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent to it by the Front Control Module. The resis-
tance in the sensor changes as temperature changes,
changing the temperature sensor signal circuit volt-
age to the Front Control Module. Based upon the
resistance in the sensor, the Front Control Module
senses a specific voltage on the temperature sensor
signal circuit, which it is programmed to correspond
to a specific temperature. The Front Control Module
then sends the proper ambient temperature mes-
sages to the EVIC, CMTC over the PCI J1850 data
bus.
The thermometer function is supported by the
ambient temperature sensor, a wiring circuit, the
Front Control Module, the Programmable Communi-
cations Interface (PCI) data bus, and a portion of the
Electronics module. If any portion of the ambienttemperature sensor circuit fails, the Front Control
Module will self-diagnose the circuit.
The ambient temperature sensor circuit can also be
diagnosed by referring toDiagnosis and Testing -
Ambient Temperature Sensor, and Diagnosis
and Testing - Ambient Temperature Sensor Cir-
cuit. If the temperature sensor and circuit are con-
firmed to be OK, but the temperature display is
inoperative or incorrect, refer toDiagnosis and
Testing - Overhead Consolein this group. For
complete circuit diagrams, refer to the appropriate
wiring information.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.
(2) Measure the resistance of the ambient temper-
ature sensor. At ±40É C (±40É F), the sensor resis-
tance is 336 kilohms. At 55É C (140É F), the sensor
resistance is 2.488 kilohms. The sensor resistance
should read between these two values. If OK, refer to
Diagnosis and Testing - Ambient Temperature
Sensor Circuitin this group. If not OK, replace the
faulty ambient temperature sensor.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR CIRCUIT
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector and the Front Control Module wire
harness connector.
(2) Connect a jumper wire between the two termi-
nals in the body half of the ambient temperature sen-
sor wire harness connector.
(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the Front Control Module wire har-
ness connector. There should be continuity. If OK, go
to Step 4. If not OK, repair the open sensor return
circuit or ambient temperature sensor signal circuit
to the ambient temperature sensor as required.
(4) Remove the jumper wire from the body half of
the ambient temperature sensor wire harness con-
nector. Check for continuity between the sensor
return circuit cavity of the Front Control Module
wire harness connector and a good ground. There
should be no continuity. If OK, go to Step 5. If not
OK, repair the shorted sensor return circuit as
required.
(5) Check for continuity between the ambient tem-
perature sensor signal circuit cavity of the Front
Control Module wire harness connector and a good
RSOVERHEAD CONSOLE8M-11
UNIVERSAL TRANSMITTER (Continued)

trically and independently using the separate power
seat switches found on the outboard seat cushion
side shield of each front seat. See the owner's manual
in the vehicle glove box for more information on the
features, use and operation of the power seat system.
OPERATION - MEMORY SYSTEM
The Memory Seat/Mirror Module (MSMM) will
drive a maximum of 2 motors at a time in a given
direction. If conflicting directions are requested, the
priority for response will be as follows:
²Seat Track Rearward
²Seat Front Down
²Seat Rear Down
²Recliner Rearward
²Seat Track Forward
²Seat Front Up
²Seat Rear Up
²Recliner Forward
The inputs from these switches to the MSMM is a
current limited battery source fed by the MSMM.
This protects the MSMM printed circuit board traces
from acting as fuses. All of these switch contact
inputs to the MSMM are normally closed to ground,
except when actuated.
Soft stops are incorporated to prevent the motor
from being driven into a stall. Should the seat have
restricted travel, refer to Resetting Soft Stops in this
section.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the memory system. For diagnosis of the MSM, the
PCI data bus, or the other electronic modules on the
PCI data bus that provide inputs and outputs for the
memory system, the use of a DRBtscan tool and the
proper Diagnostic Procedures manual are recom-
mended.
ELECTRONIC VEHICLE INFORMATION CENTER
The Electronic Vehicle Information Center (EVIC)
serves as the user interface for the memory system.
It displays memory system status messages and pro-
vides the user with the means for enabling and dis-
abling the many customer programmable features
available on the vehicle, including those for the mem-
ory system.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the EVIC. Refer toElectronic Vehicle Informa-
tion Centerin Overhead Console Systems for more
information on the EVIC.
DIAGNOSIS AND TESTING - POWER SEAT
SYSTEM
Following are tests that will help to diagnose the
hard wired components and circuits of the power seatsystem. However, if the vehicle is also equipped with
the optional memory system, these tests may not
prove conclusive in the diagnosis of the driver side
power seat. In order to obtain conclusive testing of
the driver side power seat with the memory system
option, the Programmable Communications Interface
(PCI) data bus network and all of the electronic mod-
ules that provide inputs to, or receive outputs from
the memory system components must be checked.
The most reliable, efficient, and accurate means to
diagnose the driver side power seat with the memory
system option requires the use of a DRBtscan tool
and the proper Diagnostic Procedures manual. The
DRBtscan tool can provide confirmation that the
PCI data bus is functional, that all of the electronic
modules are sending and receiving the proper mes-
sages on the PCI data bus, and that the memory sys-
tem is receiving the proper hard wired inputs and
relaying the proper hard wired outputs to perform its
driver side power seat functions.
WARNING: SOME VEHICLES ARE EQUIPPED WITH
SEATBACK MOUNTED AIRBAGS (Fig. 1). BEFORE
ATTEMPTING TO DIAGNOSE OR SERVICE ANY
SEAT OR POWER SEAT SYSTEM COMPONENT
YOU MUST FIRST DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE CABLE. THEN WAIT TWO MIN-
UTES FOR THE SYSTEM CAPACITOR TO DIS-
CHARGE BEFORE FURTHER SYSTEM SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
AIRBAG SYSTEM. FAILURE TO DO SO COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
Before any testing of the power seat system is
attempted, the battery should be fully-charged and
all of the power seat system wire harness connections
and pins cleaned and tightened to ensure proper cir-
cuit continuity and ground paths. For complete cir-
cuit diagrams, refer toPower Seatin Wiring
Diagrams.
With the dome lamp on, apply the power seat
switch in the direction of the failure. If the dome
lamp dims, the seat may be jamming. Check under
and behind the seat for binding or obstructions. If
the dome lamp does not dim, proceed with testing of
the individual components and circuits.
DIAGNOSIS AND TESTING - MEMORY SYSTEM
CHECK AND RESET SOFT STOPS
To check and reset the power memory seat soft
stops, use the power seat control switches to move
the seat in one direction to the end of travel, allow a
couple of seconds before re-energizing the seat in the
same direction until it stops and for three additional
seconds after it stops. (The amount the seat moved
RSPOWER SEATS8N-51
POWER SEATS (Continued)

OPERATION
Each Sentry Key has a unique transponder identi-
fication code permanently programmed into it by the
manufacturer. Likewise, the SKIM has a unique
9Secret Key9code programmed into it by the manu-
facturer as well. When a Sentry Key is programmed
into the memory of the SKIM, the SKIM stores the
transponder identification code from the Sentry Key,
and the Sentry Key learns the9Secret Key9code from
the SKIM. Once the Sentry Key learns the9Secret
Key9code of the SKIM, it is also permanently pro-
grammed into the transponder's memory. Therefore,
blank keys for the SKIS must be programmed by the
SKIM in addition to being cut to match the mechan-
ical coding of the ignition lock cylinder. Refer to Elec-
trical, Vehicle Theft Security, Transponder Key,
Standard Procedure - Transponder Programming.
The Sentry Key's transponder is within the range
of the SKIM's transceiver antenna ring when it is
inserted into the ignition lock cylinder. When the
ignition switch is turned to the ON position, the
SKIM communicates with the Sentry Key via a radio
frequency (RF) signal. The SKIM determines if a
valid key is present based on the information it
receives from the Sentry Key. If a valid key is
detected, that fact is communicated to the PCM via
the PCI bus and the vehicle is allowed to continue
running. If an invalid key is received by the PCM or
no status at all is communicated, the vehicle will
stall after two (2) seconds of running. The indicator
light will be flashing at this point. The Sentry Key's
transponder can not be repaired. If it is faulty or
damaged, it must be replaced.
Common communication problems:
²Two transponder keys too close together.
²Speed Pass too close to transponder key.
Solid indicator that there is a system failure.
²Loss of PCM communication.
²Failed antenna circuit.
STANDARD PROCEDURE - TRANSPONDER
PROGRAMMING
USING A DRB IIITSCAN TOOL
All Sentry Keys included with the vehicle are pre-
programmed to work with the Sentry Key Immobi-
lizer System (SKIS) when it is shipped from the
factory. The Sentry Key Immobilizer Module (SKIM)
can be programmed to recognize up to a total of eight
Sentry Keys. When programming a blank Sentry Key
transponder, the key must first be cut to match the
ignition lock cylinder of the vehicle for which it will
be used. The vehicle's four digit PIN code will be
required to complete this task since you will need it
to enter the Secured Access Mode in the SKIM. Thefollowing steps must be completed using a DRB IIIt
scan tool:
(1) Insert the blank key into the ignition and turn
it to the RUN position.
(2) Using a DRB IIItscan tool, select9Theft
Alarm,99SKIM,99Miscellaneous,9and then9Program
New Key.9
(3) Enter the four digit PIN code using the DRB
IIItscan tool. When programming is completed, the
SKIM will exit Secured Access Mode and the DRB
IIItscan tool will display the results of your attempt
to program the key. One of five distinct results may
be displayed. All five are listed below:
²(Programming Successful(is displayed if the
Sentry Key programming is successful.
²(Learned Key in Ignition(is displayed if the
key in the ignition has already been programmed
into that vehicle's SKIM.
²(Eight Keys Already Learned (At The Maxi-
mum) Programming Not Done(is displayed if
eight keys have already been programmed into the
SKIM. In this case, if a new key needs to be added
due to a lost or defective key, the9Erase All Keys9
command (which requires entering the Secured
Access Mode) has to be performed. Following the
9Erase All Keys9command, all keys that will be used
to operate the vehicleMUSTbe reprogrammed to
the SKIM.
²(Programming Not Attempted(is displayed
after an9Erase All Keys9function is executed.
²(Programming Key Failed(is displayed if fur-
ther diagnosis is required.
To learn additional keys, turn the ignition OFF,
remove the learned key, insert the next new blank
key, and repeat the steps from the beginning.
ªCUSTOMER LEARNº MODE
This feature is only available on domestic vehicles
or those which have a U.S. country code designator.
This procedure requires access to at least two valid
Sentry Keys. If two valid Sentry Keys are not avail-
able, Sentry Key programming will require the use of
a DRB IIItscan tool.
The steps required to program Sentry Keys with
two valid Sentry Keys follows:
(1) Obtain the blank Sentry Key(s) that need to be
programmed. Cut the keys to match the ignition lock
cylinder mechanical key codes.
(2) Insert one of the two valid Sentry Keys into the
ignition switch and turn the ignition switch to the
ON position.
(3) After the ignition switch has been in the ON
position for longer than three seconds, but no more
than fifteen seconds, cycle the ignition switch back to
8Q - 4 VEHICLE THEFT SECURITYRS
TRANSPONDER KEY (Continued)

CYLINDER HEAD
STANDARD PROCEDURE - VALVE SERVICE
This procedure is done with the engine cylinder
head removed from the block.
DISASSEMBLY
(1) Remove the engine cylinder head from the cyl-
inder block. Refer to cylinder head removal and
installation in this section.
(2) Use Valve Spring Compressor Tool and com-
press each valve spring.
(3) Remove the valve locks, retainers, and springs.
(4) Use an Arkansas smooth stone or a jewelers
file to remove any burrs on the top of the valve stem,
especially around the groove for the locks.
(5) Remove the valves, and place them in a rack in
the same order as removed.
VALVE CLEANING
(1) Clean all carbon deposits from the combustion
chambers, valve ports, valve stems, valve stem
guides and head.
(2) Clean all grime and gasket material from the
engine cylinder head machined gasket surface.
INSPECTION
(1) Inspect for cracks in the combustion chambers
and valve ports.
(2) Inspect for cracks on the exhaust seat.
(3) Inspect for cracks in the gasket surface at each
coolant passage.
(4) Inspect valves for burned, cracked or warped
heads.
(5) Inspect for scuffed or bent valve stems.
(6) Replace valves displaying any damage.
(7) Check valve spring height (Fig. 12).
VALVE REFACING
(1) Use a valve refacing machine to reface the
intake and exhaust valves to the specified angle.
(2) After refacing, a margin of at least 4.52-4.49
mm (.178-.177 inch) must remain (Fig. 13). If the
margin is less than 4.49 mm (.177 inch), the valve
must be replaced.
VALVE SEAT REFACING
(1) Install a pilot of the correct size in the valve
guide bore. Reface the valve seat to the specified
angle with a good dressing stone. Remove only
enough metal to provide a smooth finish.
(2) Use tapered stones to obtain the specified seat
width when required.
VALVE STAND DOWN
Valve stand down is to maintain the adequate com-
pression ratio.
(1) Invert cylinder head.
(2) Fit each valve to its respective valve guide.
(3) Using a straight edge and feeler gauge, check
valve head stand down: Inlet valve head stand down
1.08 to 1.34 mm (.042 to .052 ins.) and exhaust valve
stand down .99 to 1.25 mm (.035 to .049 ins.).
(4) If valve head stand down is not in accordance
with above, discard original valves, check stand down
with new valves and recut valve seat inserts to
obtain correct stand down.
VALVE GUIDES
(1) Valve Guides height requirement.
(2) Measurement A (Fig. 14): 13.50 - 14.00 mm.
VALVE STEM-TO-GUIDE CLEARANCE
MEASUREMENT
(1) Measure and record internal diameter of valve
guides. Valve guide internal diameter is 8.0 to 8.015
mm (.3149 to .3155 ins.).
(2) Measure valve stems and record diameters.
Intake valve stem diameter 7.94 to 7.96 mm (.3125 to
.3133 in). Exhaust valve stem diameter 7.92 to 7.94
mm (.3118 to .31215 in).
Fig. 12 VALVE SPRING CHART
LOAD Kg HEIGHT mm STATE
P1 0.00 H1 45.26 FREE LENGTH
P2 182 5 -
10%H2 38.00 VALVE CLOSED
P3 395 5% H3 28.20 VALVE OPEN
9a - 18 ENGINE 2.5L TURBO DIESELRG

DIAGNOSIS AND TESTING - EXHAUST SYSTEM
CONDITION POSSIBLE CAUSES CORRECTION
EXCESSIVE EXHAUST NOISE
(UNDER HOOD)1. Exhaust manifold cracked or
broken.1. Replace manifold.
2. Manifold to cylinder head leak. 2. Tighten manifold and/or replace
gasket.
3. EGR Valve to manifold gasket
leakage.3. Tighten fasteners or replace
gasket.
4. EGR Valve to EGR tube gasket
leakage.4. Tighten fasteners or replace
gasket.
5. EGR tube to manifold tube
leakage.5. Tighten tube nut.
6. Exhaust flex-joint to manifold
leak.6. Tighten joint fasteners and/or
replace gasket.
7. Exhaust flex-joint. 7. Replace catalytic converter
assembly.
8. Pipe and shell noise from front
exhaust pipe.8. Characteristic of single wall pipe.
EXCESSIVE EXHAUST NOISE 1. Leak at exhaust pipe joints. 1. Tighten clamps at leaking joints.
2. Burned or rusted out muffler
assembly or exhaust pipe.2. Replace muffler resonator tailpipe
assembly or exhaust pipe with
catalytic converter assembly.
3. Burned or rusted out resonator. 3. Replace muffler resonator tailpipe
assembly.
4. Restriction in exhaust system. 4. Perform exhaust restriction test.
replace component as necessary.
5. Converter material in muffler. 5. Replace muffler and converter
assemblies. Check fuel injection and
ignition systems for proper
operation.
DIAGNOSIS AND TESTING - EXHAUST SYSTEM
RESTRICTION
Exhaust system restriction can be checked by mea-
suring back pressure using the DRB IIItand PEP
module pressure tester.
WARNING: THE NORMAL OPERATING TEMPERA-
TURE OF THE EXHAUST SYSTEM IS VERY HIGH.
THEREFORE, NEVER WORK AROUND OR ATTEMPT
TO SERVICE ANY PART OF THE EXHAUST SYSTEM
UNTIL IT IS COOLED. SPECIAL CARE SHOULD BE
TAKEN WHEN WORKING NEAR THE CATALYTIC
CONVERTER. THE TEMPERATURE OF THE CON-
VERTER RISES TO A HIGH LEVEL AFTER A SHORT
PERIOD OF ENGINE OPERATION TIME.
(1) Disconnect and remove the upstream (before
catalytic converter) oxygen sensor. (Refer to 14 -FUEL SYSTEM/FUEL INJECTION/O2 SENSOR -
REMOVAL)
(2) Install the Exhaust Back Pressure Fitting
Adaptor CH8519.
(3) Connect the Low Pressure Sensor (15 psi)
CH7063 to the back pressure fitting.
(4) Following the PEP module instruction manual,
connect all required cables to the DRB IIItand PEP
module. Select the available menu options on the
DRBIIItdisplay screen for using the digital pressure
gauge function.
(5) Apply the park brake and start the engine.
(6) With transmission in Park or Neutral, raise
engine speed to 2000 RPM. Monitor the pressure
readings on the DRBIIIt. Back pressure should not
exceed specified limit. Refer to specification in table
below EXHAUST BACK PRESSURE LIMITS .
11 - 2 EXHAUST SYSTEMRS
EXHAUST SYSTEM (Continued)

TYPICAL ADAPTIVE MEMORY FUEL CELLS
Open
ThrottleOpen
ThrottleOpen
ThrottleOpen
ThrottleOpen
ThrottleOpen
Throttle Idle Decel
Vacuum 20 17 13 9 5 0
Above 1,984
rpm1 3 5 7 9 11 13 Drive 15
Below 1,984
rpm02 4 6 8 1012
Neutral14
MAP volt =0 1.4 2.0 2.6 3.3 3.9
Fuel Correction Diagnostics
There are two fuel correction diagnostic routines:
²Fuel System Rich
²Fuel System Lean
A DTC is set and the MIL is illuminated if the
PCM detects either of these conditions.
PROGRAMMABLE COMMUNICATIONS
INTERFACE (PCI) BUS
DESCRIPTION
The Programmable Communication Interface Mul-
tiplex system (PCI Bus) consist of a single wire. The
Body Control Module (BCM) acts as a splice to con-
nect each module and the Data Link Connector
(DLC) together. Each module is wired in parallel to
the data bus through its PCI chip set and uses its
ground as the bus reference. The wiring is a mini-
mum 20 gage wire.
OPERATION
Various modules exchange information through a
communications port called the PCI Bus. The Power-
train Control Module (PCM) transmits the Malfunc-
tion Indicator Lamp (Check Engine) On/Off signaland engine RPM on the PCI Bus. The PCM receives
the Air Conditioning select input, transaxle gear
position inputs over the PCI Bus. The PCM also
receives the air conditioning evaporator temperature
signal from the PCI Bus.
The following components access or send informa-
tion on the PCI Bus.
²Instrument Panel
²Body Control Module
²Air Bag System Diagnostic Module
²Full ATC Display Head
²ABS Module
²Transmission Control Module
²Powertrain Control Module
²Overhead Travel Module
SYSTEM DIAGNOSIS
OPERATION
The PCM can test many of its own input and out-
put circuits. If the PCM senses a fault in a major
system, the PCM stores a Diagnostic Trouble Code
(DTC) in memory.
For DTC information see On-Board Diagnostics.
14 - 20 FUEL INJECTIONRS
FUEL INJECTION (Continued)

GEARSHIFT CABLE ADJUSTMENT
Lift and rotate the gearshift hand lever into the
park (P) gate position and remove the ignition key.
This confirms the shift lever is in the gated park (P)
position.
After confirming the park gate position, turn the
ignition switch . If the starter will operate, the park
gate position is correct. Move the shift lever into the
neutral (N) position. If the starter will operate in this
position, the linkage is properly adjusted. If the
starter fails to operate in either position, linkage
adjustment is required.
(1) Park the vehicle on level ground and set the
parking brake.
(2) Place the gearshift lever in park (P) gate posi-
tion and remove key.
(3) Loosen the cable adjustment screw at the
transaxle operating lever (Fig. 181).
(4) Pull the transaxle operating lever fully forward
to the park detent position.
(5) Release the park brake, then rock the vehicle
to assure it is in park lock. Reset the park brake.
(6) Tighten the cable adjustment screw to 8 N´m
(70 in. lbs.). Gearshift cable should now be properly
adjusted.
(7) Verify PRNDL indicator still displays the corre-
sponding gear completely. If not, readjustment of
PRNDL may be required.(8) Check adjustment by using the preceding pro-
cedure.
GOVERNOR
DESCRIPTION
The governor assembly is fastened to the transaxle
transfer shaft. It consists of a governor body, weight,
valve, and shaft.
OPERATION
The governor meters hydraulic pressure, and this
metered pressure is used to signal the transmission
when it is time for a shift to occur. It does this by
balancing governor pressure on one side of a shift
valve, and throttle pressure on the other. When gov-
ernor pressure increases far enough to overcome the
throttle pressure on the valve, a shift occurs.
With the gearshift selector in a forward driving
range, line pressure flows from the manual valve and
down to the governor valve. When the output shaft
starts to rotate with vehicle motion, the governor
weight assembly will start to move outward due to
centrifugal force. As the weight is moved outward, it
will pull the valve with it until the land of the valve
uncovers the line pressure port. As the port begins to
become uncovered, governor pressure is metered. As
the vehicle's speed continues to increase, the weight
assembly will be at a point at which governor pres-
sure is acting on the left side of the reaction area of
the valve. This produces sufficient force to compress
the spring and allow the outer weight to move out
against the outer governor body retaining ring. At a
very high speed, the governor valve will be opened as
far as possible. In this condition, it is possible for
governor pressure to meet, but not to exceed, line
Fig. 180 Gearshift Cable at Transaxle
1 - MANUAL VALVE LEVER
2 - GEAR SHIFT CABLE
3 - UPPER MOUNT BRACKET
Fig. 181 Gearshift Cable Adjustment
1 - SHIFT CABLE ADJUSTMENT
2 - SHIFT CABLE
RSAUTOMATIC - 31TH21 - 103
GEAR SHIFT CABLE (Continued)

²an air conditioning button that allows the com-
pressor to be turned on/off. The Snowflake button
contains an LED that illuminates to shown when the
function is in operation.
²rotary knobs for front and rear fan speed selec-
tion.
²a rotary knob for mode control.
REAR CONTROL PANEL
A rear control panel centrally mounted on the
headliner has a rotary adjustment for temperature
and fan speed control of the rear unit by intermedi-
ate seat passengers when the front control rear knob
is set to the rear position.
DESCRIPTION - THREE ZONE Automatic
Temperature Control
The Three-Zone Automatic Temperature Control
(ATC) allows occupants to select a comfort tempera-
ture, which is the perceived temperature level not
the actual passenger compartment air temperature.
The Three Zone Automatic Temperature Control
system includes a dust and odor air filter. The filter
element is the same size as the air conditioning evap-
orator to ensure ample capacity. A door at the base of
the heater and air conditioning housing below the
glove box provides easy access to the filter element.
The ATC computer utilizes integrated circuitry and
information carried on the Programmable Communi-
cations Interface (PCI) data bus network to monitor
many sensors and switch inputs throughout the vehi-
cle. In response to those inputs, the internal circuitry
and programming of the ATC computer allow it to
control electronic functions and features of the ATC
system. The inputs to the ATC computer are:
²Vehicle Speed/Engine RPM± The ATC com-
puter monitors engine RPM, vehicle speed and Man-
ifold Absolute Pressure information from the PCM.
²Coolant Temperature± ATC computer moni-
tors Coolant temperature received from the PCM and
converts it to degrees Fahrenheit.
²Ambient Temperature± ATC computer moni-
tors Ambient temperature from the Compass Mini
Trip Computer (CMTC) and converts it to degrees
Fahrenheit.
²Engine Miscellaneous Sensor Status±ATC
computer monitors A/C disable information from the
PCM.
²Refrigerant Pressure± ATC computer moni-
tors Barometric Pressure, Intake Air Temperature,
High Side Pressure and Methanol Content as broad-
cast by the PCM.
²Door Ajar Status± The ATC computer moni-
tors Driver Front Door, Passenger Front Door, Left
Rear Door, Right Rear Door and Liftgate ajar infor-
mation, as identified by the Body Control Module(BCM), to determine if all in-car temperatures should
be maintained.
²Dimming± The ATC computer monitors dim-
ming status from the BCM to determine the required
level of brightness and will dim accordingly.
²Vehicle Odometer± The ATC computer moni-
tors the vehicle odometer information from the BCM
to prevent flashing the VF tube icons if the manual
motor calibration or manual cooldown tests have
failed. Flashing of the display icons will cease when
the vehicle odometer is greater than 3 miles.
²English Metric± The ATC computer monitors
the English/Metric information broadcast by the
CMTC. The set temp displays for both the front and
rear control heads will be set accordingly.
²Vehicle Identification Number± The ATC
computer monitors the last eight characters of the
VIN broadcast by the PCM and compares it to the
information stored in EEPROM. If it is different, the
new number will be stored over the old one and a
motor calibration shall be initiated.
²A/C System Information± The ATC computer
will send a message for Evaporator Temperature too
Low, Fan Blower Relay status, Evaporator Sensor
Failure, Rear Window Defogger Relay and A/C Select.
FRONT CONTROL PANEL
The front control panel and integral computer is
mounted in the instrument panel.
The instrument panel mounted control and inte-
gral computer contains:
²A power button which allows the system to be
completely turned off. The display is blank when the
system is off.
²Three rocker switches that select comfort tem-
peratures from 15É to 30É C (59É to 85É F), which are
shown in the vacuum-fluorescent digital control dis-
play. If the set temp is 59 and the down button is
pressed, the set temp value will become 55 but the
display will show LO. If the set temp is 85 and the
up button is pressed, the set temp value will become
90 but the display will show HIGH. Temperatures
can be displayed in either metric or fahrenheit,
which is controlled from the overhead console.
²A rocker switch that selects a cool-down rate.
LO-AUTO or HI-AUTO are displayed when the sys-
tem is in automatic operation.
²A defroster button which turns on the defroster
independently during full automatic control. A
defroster symbol illuminates in the display when the
button is pressed.
²Air recirculation button. A Recirculation symbol
appears in the display when the button is pressed, or
when the system exceeds 80 percent circulated air
under automatic control due to high air conditioning
demand.
24 - 2 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

cloudy days and at night it will probably be slightly
warmer. Infrared Three-Zone Temperature Control
provides side-to-side and front-to-rear variation in
comfort temperature settings. The Infrared Three-
Zone Automatic Temperature Control fan provides a
continuously variable air flow rate to meet occupant
comfort requirements.
FRONT CONTROL PANEL
²AUTO HI/LO± This system features two sets of
automatic control logic that allow either a rapid cool-
down rate or a somewhat slower cool-down rate with
less fan noise. HI-AUTO controls the system to reach
its assigned temperature quickly with a higher fan
speed. LO-AUTO controls the system to reach its
assigned temperature somewhat slower with less fan
noise. Both modes will automatically engage auto
recirculation.
²DE-FROST± The front de-frost function is
active when the rear window defogger function is
active or when the defog/defrost mode is selected.
²RECIRC± The RECIRC button will close the
air inlet door. If the system is in auto recirc (indica-
tor being displayed automatically), pressing the man-
ual recirc button will disable the auto recirc function
until one of the auto keys are pressed or the ignition
is cycled. If Auto HI/LO is pressed while manual
recirc is active, manual recirc will be deactivated.
²REAR WINDOW DEFOGGER± Pushing the
button sends a PCI bus message to the Intelligent
Power Module which controls the Rear Window
Defogger and side view mirror (if equipped) circuitry.
The defogger function will be active for 10 minutes
and can be turned off by a switch press. The defogger
will function while the control is in the OFF mode.
²FAN/MODE± The Fan and Mode knobs have
17 manual selectable positions. Manually changing
either of the rotary knobs for mode or fan speed set-
tings makes control of that function alone manual for
as long as the ignition is on. If only one is changed
manually, the other remains under automatic control.
Pressing the HI-AUTO/LO-AUTO rocker switch
restores full automatic control.
²REAR CONTROL± When the Rear System
control knob is moved to the OFF position, there will
be a delay of approximately 1 second before the sys-
tem actually turns off. This delay is to prevent an
undesired blower dropout if the knob is moved
through OFF to the other selections.
²BLOWER DELAY TIMER± The word DELAY
is displayed at start-up to signify that the system is
waiting so that cold air will not be blowing. This tells
the operator that it is unnecessary to turn the sys-
tem off, raise the temperature setting or turn the fan
speed setting down to prevent cold air from blowing.
A countdown in minutes and seconds until the engineis warm enough to begin delivering heat to the pas-
sengers alternates with the DELAY message at 25
second intervals. This countdown is based on actual
measurement of the rate of engine coolant tempera-
ture change. During the delay time, Defrost mode is
selected and the fan operates at a low speed to keep
the windshield fog free.
REAR CONTROL PANEL
Primary control of the rear compartment unit is in
the instrument panel center stack. The rear unit con-
trol knob there allows the driver to turn the rear
unit off, allow control by the intermediate seat occu-
pants by switching to the REAR position, or provide
fully automatic control based on the temperature set-
ting shown on the front control display.
²REAR CONTROL± Selecting automatic control
of the rear unit at the instrument panel, illuminates
a Locked Padlock in the rear control panel display.
Selecting REAR activates the rear control panel and
the Padlock then appears unlocked.
²FAN KNOB± The rear fan control has Off and
AUTO positions and a range of manual speed set-
tings that override the AUTO setting.
²MODE KNOB± The mode control allows inter-
mediate seat occupants to manually override the
automatic mode and select any balance of air flow
between overhead and floor outlets from full over-
head to full floor.
²SET TEMP± The rear set temp control will
operate identical to the front controls. If the front
control rear set temp button is pressed simulta-
neously with the rear control head, then the front
control head press events shall have priority, i.e. if
the front user presses Rear Set Temp down and the
rear user presses Set Temp up, then the rear set
temp will decrease.
DIAGNOSIS AND TESTING - A/C COOL DOWN
TEST
The heater-A/C control module can perform an A/C
cool down test, which is a test performed during the
manufacturing process to confirm that the air condi-
tioning system is performing satisfactorily. This test
can also provide a quick confirmation of air condi-
tioning system performance to the service technician.
If the test is completed satisfactorily, no further ser-
vice is required. If the test is failed, proceed to the
A/C Performance Test to confirm the a/c system is
operating properly, or use a DRBIIItscan tool to
diagnose the A/C system control and distribution sys-
tems. Refer to the appropriate diagnostic informa-
tion.
24 - 4 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)