disarming. The rolling code algorithm ensures secu-
rity by preventing an override of the SKIS through
the unauthorized substitution of the SKIM or the
PCM. However, the use of this strategy also means
that replacement of either the SKIM or the PCM
units will require a system initialization procedure to
restore system operation.
When the ignition switch is turned to the ON or
START positions, the SKIM transmits an RF signal
to excite the Sentry Key transponder. The SKIM then
listens for a return RF signal from the transponder
of the Sentry Key that is inserted in the ignition lock
cylinder. If the SKIM receives an RF signal with
valid ªSecret Keyº and transponder identification
codes, the SKIM then sends a ªvalid keyº message to
the PCM over the PCI bus. If the SKIM receives an
invalid RF signal or no response, it sends ªinvalid
keyº messages to the PCM. The PCM will enable or
disable engine operation based upon the status of the
SKIM messages.
The SKIM also sends messages to the instrument
cluster over the PCI bus network to control the VTSS
indicator LED. The SKIM sends messages to the
instrument cluster to turn the LED on for about
three seconds when the ignition switch is turned to
the ON position as a bulb test. After completion of
the bulb test, the SKIM sends bus messages to keep
the LED off for a duration of about one second. Then
the SKIM sends messages to turn the LED on or off
based upon the results of the SKIS self-tests. If the
VTSS indicator LED comes on and stays on after the
bulb test, it indicates that the SKIM has detected a
system malfunction and/or that the SKIS has become
inoperative.
If the SKIM detects an invalid key when the igni-
tion switch is turned to the ON position, it sends
messages to the instrument cluster to flash the VTSS
indicator LED. The SKIM can also send messages to
the instrument cluster to flash the LED and to gen-
erate a single audible chime tone. These functions
serve as an indication to the customer that the SKIS
has been placed in its ªCustomer Learnº program-
ming mode. See Sentry Key Immobilizer System
Transponder Programming in this group for more
information on the ªCustomer Learnº programming
mode.
For diagnosis or initialization of the SKIM and the
PCM, a DRB IIItscan tool and the proper Body
Diagnostic Procedures Manual are required. The
SKIM cannot be repaired, and if faulty or damaged,
the unit must be replaced.
SENTRY KEY IMMOBILIZER SYSTEM
TRANSPONDER
The Sentry Key Immobilizer System (SKIS) uses a
transponder that is integral to each of three ignitionkey that are supplied with the vehicle when it is
shipped from the factory. The transponder chip is
insulated within a nylon mount inserted in the head
of the key, and invisible beneath a molded rubber cap
(Fig. 2).
Each Sentry Key transponder has a unique tran-
sponder identification code programmed into it by the
manufacturer. The Sentry Key Immobilizer Module
(SKIM) has a unique ªSecret Keyº code programmed
into it by the manufacturer. When a Sentry Key
transponder is programmed into the memory of the
SKIM, the SKIM learns the transponder identifica-
tion code from the transponder, and the transponder
learns the ªSecret Keyº code from the SKIM. Each of
these codes is stored within the transponder and in
the nonvolatile memory of the SKIM. Therefore,
blank keys for the SKIS must be programmed by and
into the SKIM, in addition to being cut to match the
mechanical coding of the ignition lock cylinder. See
Sentry Key Immobilizer System Transponder Pro-
gramming in this group for more information.
The Sentry Key transponder is within the range of
the SKIM transceiver antenna ring when it is
inserted in the ignition lock cylinder. When the igni-
tion switch is turned to the START or RUN positions,
the SKIM transceiver issues a Radio Frequency (RF)
signal that excites the transponder chip. The tran-
sponder chip responds by issuing an RF signal con-
taining its transponder identification code and the
ªSecret Keyº code. The SKIM transceiver compares
the transponder codes with the codes stored in its
Fig. 2 Sentry Key Immobilizer Transponder
1 ± MOLDED CAP
2 ± TRANSPONDER
3 ± MOLDED CAP REMOVED
4 ± SENTRY KEY
PLVEHICLE THEFT/SECURITY SYSTEM 8Q - 3
DESCRIPTION AND OPERATION (Continued)
POWER MIRRORS
TABLE OF CONTENTS
page page
GENERAL INFORMATION
INTRODUCTION..........................1
DIAGNOSIS AND TESTING
POWER FOLD AWAY MIRROR SWITCH TEST...1POWER FOLD AWAY MIRROR MOTOR........1
REMOVAL AND INSTALLATION
POWER FOLD-AWAY MIRROR SWITCH.......1
POWER FOLD-AWAY MIRROR...............2
GENERAL INFORMATION
INTRODUCTION
These vehicles may be equipped with Power Fold
Away Mirrors. The vehicle has an additional switch
in the switch pod that controls the folding function of
the mirror assembly (Fig. 1).
All vehicles are equipped with a Ignition-Off Draw
Fuse, and they are disconnected when the vehicles
are originally shipped from the factory. Disconnecting
this fuse will help prevent the battery from discharge
during storage. The fuse is located in Power Distri-
bution Center (PDC) refer to the cover for proper
location.
This fuse is included in the power mirror circuity
and should be checked if the mirrors are inoperative.
The vehicle mirror circuitry is powered from the
accessory feed circuit and protected by a 15 amp cir-
cuit breaker and power mirror relay. The relay pro-
vides for the switching of the mirror. The circuit
breaker and mirror relay are located in the inner
door panel wire harness.
DIAGNOSIS AND TESTING
POWER FOLD AWAY MIRROR SWITCH TEST
(1) Remove power mirror switch from the door
trim panel. Refer to the switch removal and installa-
tion procedure in this group.
(2) Using an ohmmeter, test for continuity between
the terminals of the switch as shown in the Power
Fold Away Mirror Switch Test (Fig. 2).
(3) If test results are not obtained as shown in
(Fig. 2), replace the switch.
Refer to Group 8W, Wiring Diagrams for a com-
plete schematic of the power mirror circuitry.
POWER FOLD AWAY MIRROR MOTOR
The power fold away mirror motor is incorporated
into the mirror assembly. If the motor proves to be
inoperative the entire mirror assembly must be
replaced. Refer to the mirror removal and installa-
tion procedure in this group for detailed instructions.
(1) Remove the power mirror switch from the door
trim panel. Refer to the removal and installation pro-
cedure in this group.
(2) Disconnect the mirror switch electrical connec-
tor.
(3) Using two jumper wires, one connected to a 12
volt source, and the other connected to a good body
ground. Refer to the Mirror Switch Circuits (Fig. 3)
and check for the appropriate mirror responses.
(4) If test results are not obtained as shown in
(Fig. 3), check for a open or shorted circuit, or replace
mirror / motor assembly as necessary.
Refer to Group 8W, Wiring Diagrams for a com-
plete wiring schematic of the power mirror circuitry.
REMOVAL AND INSTALLATION
POWER FOLD-AWAY MIRROR SWITCH
REMOVAL
(1) Disconnect the negative battery cable.
Fig. 1 Power Fold Away Mirror Switch
PLPOWER MIRRORS 8T - 1
TEST TWO (SELECTOR IN 2)
(1) Attach one gauge to line pressure port, and tee
another gauge into lower cooler line fitting. This will
allow lubrication pressure readings to be taken..
(2) Operate engine at 1000 rpm for test.
(3) Move selector lever on transaxle one detent for-
ward from full rearward position. This is selector 2
position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi. as lever is moved counter-
clockwise.
(6) Lubrication pressure should be 10 to 25 psi
with lever clockwise and 10 to 35 psi with lever at
full counterclockwise.
(7) This tests pump output, pressure regulation,
and condition of rear clutch and lubrication hydraulic
circuits.
TEST THREE (SELECTOR IN D)
(1) Attach gauges to line and kickdown release
ports.
(2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle two detents
forward from full rearward position. This is selector
D position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise to the full
counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise. Pressure should gradually
increase to 80 to 88 psi. as lever is moved counter-
clockwise.
(6) Kickdown release is pressurized only in direct
drive and should be same as line pressure within 3
psi, up to kickdown point.
(7) This tests pump output, pressure regulation,
and condition of rear clutch, front clutch, and
hydraulic circuits.
TEST FOUR (SELECTOR IN REVERSE)
(1) Attach 300 psi gauge to low-reverse port.
(2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle four detents
forward from full rearward position. This is selector
R position.
(4) Low/reverse pressure should read 180 to 220
psi with throttle lever clockwise. Pressure should
gradually increase to 260 to 300 psi. as lever is
moved counterclockwise.
(5) This tests pump output, pressure regulation,
and condition of front clutch and rear servo hydraulic
circuits.(6) Move selector lever on transaxle to D position
to check that low/reverse pressure drops to zero.
(7) This tests for leakage into rear servo, due to
case porosity, which can cause reverse band burn out.
TEST RESULT INDICATIONS
(1) If proper line pressure, minimum to maximum,
is found in any one test, the pump and pressure reg-
ulator are working properly.
(2) Low pressure in D, 1, and 2 but correct pres-
sure in R, indicates rear clutch circuit leakage.
(3) Low pressure in D and R, but correct pressure
in 1 indicates front clutch circuit leakage.
(4) Low pressure in R and 1, but correct pressure
in 2 indicates rear servo circuit leakage.
(5) Low line pressure in all positions indicates a
defective pump, a clogged filter, or a stuck pressure
regulator valve.
GOVERNOR PRESSURE
Test only if transaxle shifts at wrong vehicle
speeds when throttle cable is correctly adjusted.
(1) Connect a 0-150 psi pressure gauge to governor
pressure take-off point. It is located at lower right
side of case, below differential cover.
(2) Operate transaxle in third gear to read pres-
sures. The governor pressure should respond
smoothly to changes in mph and should return to 0
to 3 psi when vehicle is stopped. High pressure
(above 3 psi) at standstill will prevent the transaxle
from downshifting.
THROTTLE PRESSURE
No gauge port is provided for throttle pressure.
Incorrect throttle pressure should be suspected if
part throttle upshift speeds are either delayed or
occur too early in relation to vehicle speed. Engine
runaway on shifts can also be an indicator of low
throttle pressure setting, or misadjusted throttle
cable.
In no case should throttle pressure be adjusted
until the transaxle throttle cable adjustment has
been verified to be correct.
CLUTCH AND SERVO AIR PRESSURE TESTS
A no±drive condition might exist even with correct
fluid pressure, because of inoperative clutches or
bands. The inoperative units, clutches, bands, and
servos can be located through a series of tests. This
is done by substituting air pressure for fluid pressure
(Fig. 7).
The front and rear clutches, kickdown servo, and
low/reverse servo can be tested by applying air pres-
sure to their respective passages. To make air pres-
sure tests, proceed as follows:
21 - 68 TRANSAXLEPL
DIAGNOSIS AND TESTING (Continued)
SERVICE PROCEDURES
PRESSURE GAUGES
A quality air pressure gauge is recommended to
check tire pressure. After checking the air pressure,
replace valve cap finger tight.
TIRE INFLATION PRESSURES
Under inflation causes rapid shoulder wear, tire
flexing, and can result in tire failure (Fig. 5).
Over inflation causes rapid center wear and loss of
the tire's ability to cushion shocks (Fig. 6).
Improper inflation can cause:
²Uneven wear patterns
²Reduced tread life
²Reduced fuel economy
²Unsatisfactory ride²The vehicle to drift.
For proper tire pressure specification refer to the
Tire Inflation Pressure Chart Placard provided with
the vehicle.
Tire pressures have been chosen to provide safe
operation, vehicle stability, and a smooth ride. Tire
pressure should be checked cold once per month.
Check tire pressure more frequently when the
weather temperature varies widely. Tire pressure will
decrease when the outdoor temperature drops.
Inflation pressures specified on the placard are
always the cold inflation pressure of the tire. Cold
inflation pressure is obtained after the vehicle has
not been operated for at least 3 hours, or the vehicle
is driven less than one mile after being inoperative
for 3 hours. Tire inflation pressures may increase
from 2 to 6 pounds per square inch (psi) during oper-
ation. Do not reduce this normal pressure build-up.
WARNING: OVER OR UNDER INFLATED TIRES
CAN AFFECT VEHICLE HANDLING. THE TIRE CAN
FAIL SUDDENLY, RESULTING IN LOSS OF VEHICLE
CONTROL.
TIRE PRESSURE FOR HIGH SPEED
OPERATION
DaimlerChrysler Corporation advocates driving at
safe speeds within posted speed limits. Where speed
limits allow the vehicle to be driven at high speeds,
correct tire inflation pressure is very important. For
speeds up to and including 120 km/h (75 mph), tires
must be inflated to the pressures shown on the tire
placard. For continuous speeds in excess of 120 km/h
(75 mph), tires must be inflated to the maximum
pressure specified on the tire sidewall.
Vehicles loaded to the maximum capacity should
not be driven at continuous speeds above 75 mph
(120 km/h).
For emergency vehicles that are driven at speeds
over 90 mph (144 km/h), special high speed tires
must be used. Consult tire manufacturer for correct
inflation pressure recommendations.
TIRE AND WHEEL ROTATION
NON-DIRECTIONAL TREAD PATTERN TIRES
Tires on the front and rear axles operate at differ-
ent loads and perform different functions. For these
reasons, they wear at unequal rates, and tend to
develop irregular wear patterns. These effects can be
reduced by timely rotation of tires. The benefits of
rotation are especially worthwhile. Rotation will
increase tread life, help to maintain mud, snow, and
wet traction levels, and contribute to a smooth, quiet
ride.
Fig. 5 Under Inflation Wear
1 ± THIN TIRE TREAD AREAS
Fig. 6 Over Inflation Wear
1 ± THIN TIRE TREAD AREA
22 - 6 TIRES AND WHEELSPL
Pending ConditionsÐ
²Misfire DTC
²Front Oxygen Sensor Response
²Front Oxygen Sensor Heater Monitor
²Front Oxygen Sensor Electrical
²Rear Oxygen Sensor Rationality (middle check)
²Rear Oxygen Sensor Heater Monitor
²Rear Oxygen Sensor Electrical
²Fuel System Monitor
²All TPS faults
²All MAP faults
²All ECT sensor faults
²Purge flow solenoid functionality
²Purge flow solenoid electrical
²All PCM self test faults
²All CMP and CKP sensor faults
²All injector and ignition electrical faults
²Idle Air Control (IAC) motor functionality
²Vehicle Speed Sensor
²Brake switch
²Intake air temperature
ConflictÐThe catalyst monitor does not run if
any of the following are conditions are present:
²EGR Monitor in progress
²Fuel system rich intrusive test in progress
²EVAP Monitor in progress
²Time since start is less than 60 seconds
²Low fuel level
²Low ambient air temperature
SuspendÐThe Task Manager does not mature a
catalyst fault if any of the following are present:
²Oxygen Sensor Monitor, Priority 1
²Upstream Oxygen Sensor Heater, Priority 1
²EGR Monitor, Priority 1
²EVAP Monitor, Priority 1
²Fuel System Monitor, Priority 2
²Misfire Monitor, Priority 2
NON-MONITORED CIRCUITS
OPERATION
The PCM does not monitor all circuits, systems
and conditions that could have malfunctions causing
driveability problems. However, problems with these
systems may cause the PCM to store diagnostic trou-
ble codes for other systems or components. For exam-
ple, a fuel pressure problem will not register a fault
directly, but could cause a rich/lean condition or mis-
fire. This could cause the PCM to store an oxygen
sensor or misfire diagnostic trouble code.
The major non-monitored circuits are listed below
along with examples of failures modes that do not
directly cause the PCM to set a DTC, but for a sys-
tem that is monitored.FUEL PRESSURE
The fuel pressure regulator controls fuel system
pressure. The PCM cannot detect a clogged fuel
pump inlet filter, clogged in-line fuel filter, or a
pinched fuel supply or return line. However, these
could result in a rich or lean condition causing the
PCM to store an oxygen sensor or fuel system diag-
nostic trouble code.
SECONDARY IGNITION CIRCUIT
The PCM cannot detect an inoperative ignition coil,
fouled or worn spark plugs, ignition cross firing, or
open spark plug cables.
CYLINDER COMPRESSION
The PCM cannot detect uneven, low, or high engine
cylinder compression.
EXHAUST SYSTEM
The PCM cannot detect a plugged, restricted or
leaking exhaust system. It may set a EGR or Fuel
system fault or O2S.
FUEL INJECTOR MECHANICAL MALFUNCTIONS
The PCM cannot determine if a fuel injector is
clogged, the needle is sticking or if the wrong injector
is installed. However, these could result in a rich or
lean condition causing the PCM to store a diagnostic
trouble code for either misfire, an oxygen sensor, or
the fuel system.
EXCESSIVE OIL CONSUMPTION
Although the PCM monitors engine exhaust oxygen
content when the system is in closed loop, it cannot
determine excessive oil consumption.
THROTTLE BODY AIR FLOW
The PCM cannot detect a clogged or restricted air
cleaner inlet or filter element.
VACUUM ASSIST
The PCM cannot detect leaks or restrictions in the
vacuum circuits of vacuum assisted engine control
system devices. However, these could cause the PCM
to store a MAP sensor diagnostic trouble code and
cause a high idle condition.
PCM SYSTEM GROUND
The PCM cannot determine a poor system ground.
However, one or more diagnostic trouble codes may
be generated as a result of this condition. The mod-
ule should be mounted to the body at all times, also
during diagnostic.
PLEMISSION CONTROL SYSTEMS 25 - 23
DESCRIPTION AND OPERATION (Continued)