The PCM compares the upstream and downstream
heated oxygen sensor inputs to measure catalytic con-
vertor efficiency. If the catalyst efficiency drops below
the minimum acceptable percentage, the PCM stores a
diagnostic trouble code in memory, after 2 trips.
During certain idle conditions, the PCM may enter
a variable idle speed strategy. During variable idle
speed strategy the PCM adjusts engine speed based
on the following inputs.
²A/C sense
²Battery voltage
²Battery temperature or Calculated Battery Tem-
perature
²Engine coolant temperature
²Engine run time
²Inlet/Intake air temperature
²Vehicle mileage
ACCELERATION MODE
This is a CLOSED LOOP mode. The PCM recog-
nizes an abrupt increase in Throttle Position sensor
output voltage or MAP sensor output voltage as a
demand for increased engine output and vehicle
acceleration. The PCM increases injector pulse width
in response to increased fuel demand.
²Wide Open Throttle-open loop
DECELERATION MODE
This is a CLOSED LOOP mode. During decelera-
tion the following inputs are received by the PCM:
²A/C sense
²Battery voltage
²Inlet/Intake air temperature
²Engine coolant temperature
²Crankshaft position (engine speed)
²Exhaust gas oxygen content (upstream heated
oxygen sensor)
²Knock sensor
²Manifold absolute pressure
²Throttle position sensor
²IAC motor (solenoid) control changes in response
to MAP sensor feedback
The PCM may receive a closed throttle input from
the Throttle Position Sensor (TPS) when it senses an
abrupt decrease in manifold pressure. This indicates a
hard deceleration (Open Loop). In response, the PCM
may momentarily turn off the injectors. This helps
improve fuel economy, emissions and engine braking.
WIDE-OPEN-THROTTLE MODE
This is an OPEN LOOP mode. During wide-open-
throttle operation, the following inputs are used by
the PCM:
²Inlet/Intake air temperature
²Engine coolant temperature
²Engine speed
²Knock sensor²Manifold absolute pressure
²Throttle position
When the PCM senses a wide-open-throttle condi-
tion through the Throttle Position Sensor (TPS) it de-
energizes the A/C compressor clutch relay. This
disables the air conditioning system and disables
EGR (if equipped).
The PCM adjusts injector pulse width to supply a
predetermined amount of additional fuel, based on
MAP and RPM.
IGNITION SWITCH OFF MODE
When the operator turns the ignition switch to the
OFF position, the following occurs:
²All outputs are turned off, unless 02 Heater
Monitor test is being run. Refer to the Emission sec-
tion for On-Board Diagnostics.
²No inputs are monitored except for the heated
oxygen sensors. The PCM monitors the heating ele-
ments in the oxygen sensors and then shuts down.
FUEL CORRECTION or ADAPTIVE MEMORIES
DESCRIPTION
In Open Loop, the PCM changes pulse width with-
out feedback from the O2 Sensors. Once the engine
warms up to approximately 30 to 35É F, the PCM
goes into closed loopShort Term Correctionand
utilizes feedback from the O2 Sensors. Closed loop
Long Term Adaptive Memoryis maintained above
170É to 190É F unless the PCM senses wide open
throttle. At that time the PCM returns to Open Loop
operation.
OPERATION
Short Term
The first fuel correction program that begins func-
tioning is the short term fuel correction. This system
corrects fuel delivery in direct proportion to the read-
ings from the Upstream O2 Sensor.
The PCM monitors the air/fuel ratio by using the
input voltage from the O2 Sensor. When the voltage
reaches its preset high or low limit, the PCM begins
to add or remove fuel until the sensor reaches its
switch point. The short term corrections then begin.
The PCM makes a series of quick changes in the
injector pulse-width until the O2 Sensor reaches its
opposite preset limit or switch point. The process
then repeats itself in the opposite direction.
Short term fuel correction will keep increasing or
decreasing injector pulse-width based upon the
upstream O2 Sensor input. The maximum range of
authority for short term memory is 25% (+/-) of base
pulse-width. Short term is violated and is lost when
ignition is turned OFF.
RSFUEL INJECTION14-19
FUEL INJECTION (Continued)
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REMOVAL
REMOVAL - PEDAL POSITION SENSOR (LHD)
(1) Disconnect negative battery cable.
(2) Disconnect pedal position sensor electrical con-
nector (Fig. 4).
(3) Remove 2 pedal position sensor retaining nuts
(Fig. 4).
(4) Remove pedal position sensor from vehicle.
REMOVAL - PEDAL POSITION SENSOR (RHD)
(1) Disconnect negative battery cable.
(2) Disconnect pedal position sensor electrical con-
nector (Fig. 4).
(3) Remove 2 pedal position sensor retaining nuts
(Fig. 4).
(4) Remove pedal position sensor from vehicle.
INSTALLATION
INSTALLATION - PEDAL POSITION SENSOR
(LHD)
(1) Position pedal position sensor in vehicle.
(2) Install pedal position sensor retaining nuts
(Fig. 4).
(3) Connect pedal position sensor electrical connec-
tor (Fig. 4).
(4) Connect negative battery cable.
INSTALLATION - PEDAL POSITION SENSOR
(RHD)
(1) Position pedal position sensor in vehicle.
(2) Install 2 pedal position sensor retaining nuts
(Fig. 4).
(3) Connect pedal position sensor electrical connec-
tor (Fig. 4).
(4) Connect negative battery cable.
BOOST PRESSURE SENSOR
DESCRIPTION
The boost pressure/ intake air temperature sensor
is mounted to the top of the intake manifold. The
sensor allows the ECM to monitor air pressure
within the intake manifold. This sensor is also used
to monitor the intake air temperature (Fig. 5).
OPERATION
When the intake manifold pressure is low (high
vacuum) sensor voltage output is 0.25-1.8 volts at the
ECM. When the intake manifold pressure is high due
to turbo boost, sensor voltage output is 2.0-4.7 volts.
The sensor receives a 5-volts reference from the
ECM. Sensor ground is also provides by the ECM.
The ECM uses boost pressure combined with intake
air temerature to determine the volume of air enter-
ing the engine.
DIAGNOSIS AND TESTING - BOOST
PRESSURE/INTAKE AIR TEMPERATURE
SENSOR
If the boost pressure sensor fails, the ECM records
a DTC into memory and continues to operate the
engine in one of the three limp-in modes. When the
ECM is operating in this mode, a loss of power will
be present, as if the turbocharger was not operating.
The best method for diagnosing faults with the boost
pressure sensor is with the DRB IIItscan tool. Refer
to the Diesel Powertrain Diagnostic Manual for more
information.
Refer to On-Board Diagnostics in Emissions Con-
trol System for a list of Diagnostic Trouble Codes
(DTC's) for certain fuel system components.
Fig. 5 BOOST PRESSURE SENSOR/INTAKE AIR
TEMPERATURE SENSOR
14a - 14 FUEL INJECTIONRG
ACCELERATOR PEDAL POSITION SENSOR (Continued)
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NOTE: Snap ring ends must be located within one
finger of the input clutch hub. Be sure that snap
ring is fully seated, by pushing with screwdriver,
into snap ring groove all the way around.
(14) Seat tapered snap ring to ensure proper
installation (Fig. 271).
(15) Install input clutch assembly to the Input
Clutch Pressure Fixture±Tool 8391 (Fig. 272).(16) Set up dial indicator on the UD clutch pack as
shown in (Fig. 273).
(17) Using moderate pressure, press down and
hold (near indicator) the UD clutch pack with screw-
driver or suitable tool and zero dial indicator (Fig.
274). When releasing pressure on clutch pack, indica-
tor reading should advance 0.005±0.010.
CAUTION: Do not apply more than 30 psi (206 kPa)
to the underdrive clutch pack.
(18) Apply 30 psi (206 kPa) to the underdrive hose
on Tool 8391 and measure UD clutch clearance. Mea-
sure and record UD clutch pack measurement in four
(4) places, 90É apart.
Fig. 271 Seating Tapered Snap Ring
1 - OVERDRIVE/UNDERDRIVE CLUTCHES REACTION PLATE
TAPERED SNAP RING
2 - SCREWDRIVER
Fig. 272 Input Clutch Assembly on Pressure Fixture
Tool 8391
1 - INPUT CLUTCH ASSEMBLY
2 - INPUT CLUTCH PRESSURE FIXTURE 8391
Fig. 273 Set Up Dial Indicator to Measure UD Clutch
Clearance
1 - DIAL INDICATOR
2 - UNDERDRIVE CLUTCH
RS41TE AUTOMATIC TRANSAXLE21 - 267
INPUT CLUTCH ASSEMBLY (Continued)
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(5)2.4L Gas models goto Step 10. 2.5L TD
Models:Install coolant recovery bottle bracket (Fig.
144).
(6) Install coolant recovery bottle to bracket.
(7) Connect battery temperature sensor to battery
tray. Install battery tray into position (Fig. 145).(8) Install battery, hold-down clamp, and nut (Fig.
146).
(9) Install battery thermal shield (Fig. 147).
Fig. 144 Coolant Recovery Bottle Bracket
1 - COOLANT RECOVERY BOTTLE BRACKET
2 - NUT
3 - MOUNT BRACKET
Fig. 145 Battery Tray
1 - BATTERY TRAY
Fig. 146 Battery and Hold-Down Clamp
1 - BATTERY
2 - HOLD-DOWN CLAMP
Fig. 147 Battery Thermal Shield
1 - BATTERY THERMAL SHIELD
21 - 364 T850 MANUAL TRANSAXLERS
GEARSHIFT CABLE - CROSSOVER (Continued)
ProCarManuals.com
(10)2.4L Gas models goto Step 15. 2.5L TD
Models:Remove battery thermal shield (Fig. 167).
(11) Remove battery hold down nut, clamp, and
battery (Fig. 168).(12) Remove battery tray (Fig. 169). Disconnect
battery temperature sensor.
(13) Remove coolant recovery bottle from bracket.
(14) Remove coolant recovery bottle mounting
bracket (Fig. 170).
Fig. 167 Battery Thermal Shield
1 - BATTERY THERMAL SHIELD
Fig. 168 Battery and Hold-Down Clamp
1 - BATTERY
2 - HOLD-DOWN CLAMP
Fig. 169 Battery Tray
1 - BATTERY TRAY
Fig. 170 Coolant Recovery Bottle Bracket
1 - COOLANT RECOVERY BOTTLE BRACKET
2 - NUT
3 - MOUNT BRACKET
21 - 370 T850 MANUAL TRANSAXLERS
GEARSHIFT CABLE - SELECTOR (Continued)
ProCarManuals.com
(15) Disconnect crossover cable from transaxle
crossover lever (Fig. 171).
(16) Remove crossover cable retainer clip and dis-
engage cable from mount bracket (Fig. 171).
(17) Raise vehicle on hoist.
(18) Remove selector cable from engine compart-
ment, then remove cable from passenger compart-
ment through opening in floor pan.
INSTALLATION
(1) From underneath vehicle, install gearshift
selector cable into passenger compartment through
floor pan hole. Install remainder of cable into posi-
tion in engine compartment.
(2) Lower vehicle.
(3) Install selector cable to mount bracket and
secure with retainer clip (Fig. 172).
(4) Install cable to transaxle selector lever (Fig.
172).
(5)2.4L Gas models goto Step 10. 2.5L TD
models:Install coolant recovery bottle bracket (Fig.
173).
Fig. 171 Gearshift Cables at Transaxle
1 - SELECTOR CABLE
2 - CABLE RETAINER
3 - CABLE RETAINER
4 - CROSSOVER CABLE
5 - MOUNT BRACKET
Fig. 172 Gearshift Cables at Transaxle
1 - SELECTOR CABLE
2 - CABLE RETAINER
3 - CABLE RETAINER
4 - CROSSOVER CABLE
5 - MOUNT BRACKET
Fig. 173 Coolant Recovery Bottle Bracket
1 - COOLANT RECOVERY BOTTLE BRACKET
2 - NUT
3 - MOUNT BRACKET
RST850 MANUAL TRANSAXLE21 - 371
GEARSHIFT CABLE - SELECTOR (Continued)
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INSTALLATION
NOTE: The crossbar assemblies are designed to be
installed in only one way. Check top and bottom
surfaces of the crossbar for the word FRONT and
directional arrows. The directional arrows must
point toward the front of the vehicle.
(1) Place crossbar in position on vehicle.
(2) Work from side to side sliding the crossbar
assembly back a little at a time to ensure it remains
perpendicular to the side rails.
(3) Position first crossbar assembly crossbar at the
second most rearward locator holes. Press the top of
the stanchion lever to lock it into position.
(4) Position the second crossbar assembly in the
second hole from the front. Lock into place.
(5) Place luggage rack riser into position.
(6) Install two fasteners into riser. Tighten fasten-
ers to 4 mm (35 in. lbs.) torque.
REAR QUARTER PANEL/
FENDER AIR EXHAUSTER
DESCRIPTION
Air exhausters, designed to conform to the body
structure, allow air entering at the front of the vehi-
cle to flow out the back. By reducing air pressure
within the vehicle, the exhausters also reduce blower
noise at any given air flow level compared to operat-
ing without them and help reduce door closing effort.
They are located in the lower rear comers of the
body.
REMOVAL
SHORT WHEELBASE
(1) Remove the rear fascia from the body. (Refer to
13 - FRAMES & BUMPERS/BUMPERS/REAR FAS-
CIA - REMOVAL).
(2) Using a trim stick or another suitable wide flat
bladed tool, carefully pry the air exhauster away
from the opening in the lower aperture panel until
the snap features release (Fig. 19).
(3) Remove the air exhauster from the hole in the
lower aperture panel.
LONG WHEELBASE
NOTE: Models with the optional rear heater and air
conditioner do not have an air exhauster on the
right side of the vehicle, but have a plastic plug
installed in the right lower aperture panel. This plug
is removed using the same procedure used toremove the air exhauster from the short wheelbase
model. Refer to SHORT WHEELBASE .
(1) Remove the quarter trim panel from the inside
of the left or right quarter inner panel (Refer to 23 -
BODY/INTERIOR/RIGHT QUARTER TRIM PANEL
- REMOVAL) or (Refer to 23 - BODY/INTERIOR/
LEFT QUARTER TRIM PANEL - REMOVAL).
(2) Using a trim stick or another suitable wide flat
bladed tool, carefully pry the air exhauster away
from the opening in the lower aperture panel until
the snap features release (Fig. 20).
(1) Remove the air exhauster from the hole in the
lower aperture panel.
Fig. 19 AIR EXHAUSTER - SWB
1 - LOWER APERTURE PANEL
2 - AIR EXHAUSTER
Fig. 20 AIR EXHAUSTER - LWB
1 - AIR EXHAUSTER
2 - PLUG
3 - LOWER APERTURE PANEL
RSEXTERIOR23-57
LUGGAGE RACK CROSSBAR (Continued)
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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.
²Rear window defogger on/off switch. A graphic
symbol shows when the defroster is on.
²An air conditioning button that allows the com-
pressor to be turned off. A Snowflake symbol is illu-
minated when air conditioning is on, whether under
manual or automatic control.
²Rotary knob for front fan speed selection can
override the automatic controls. LEDs surrounding
the knob show the current setting.
²Rotary knob for control of the Rear system.
²A rotary knob for mode control can override the
automatic controls. LEDs surrounding the knob show
the current setting.
²Computer logic remembers the settings of the
controls when the ignition is turned off and retains
those settings after a restart. If the system is off
when the ignition is turned off it will be off when the
engine is restarted, etc.
²Computer logic provides variable air recircula-
tion under high temperature and humidity condi-
tions. Because recirculation is generally accompanied
by increased fan noise, the proportion of recirculated
to outside air gradually approaches full recirculation
over a broad temperature range.
²A graphic symbol of the windshield that illumi-
nates when the windshield wiper deicer is active.
REAR CONTROL PANEL
A rear control panel centrally mounted on the
headliner includes a vacuum-flourescent digital dis-
play, a rocker control for temperature and rotary con-
trols for adjustment of mode and fan speed control of
the rear unit by intermediate seat passengers.
OPERATION
OPERATION - DUAL ZONE
²The mode control knob enables continously vari-
able proportioning of air flow between modes but has
detents adjacent to each icon.
²The blower control provides five separate speeds.
²When the fan is off, the HVAC computer closes
the recirculation door to prevent outside air from
entering the passenger compartment.
²Interior air may be recirculated to speed up
heating or cooling in all modes except defrost and
mix by pressing the Recirculate button on the control
panel.
²To reduce humidity for rapid defogging the A/C
compressor runs automatically in modes from ªmix'
to full defrost when outside temperatures are above
freezing.
²Air conditioning is available in any mode by
pressing the snowflake, A/C on/off, button.
OPERATION - MANUAL THREE ZONE
FRONT CONTROL PANEL
²Primary control of the rear compartment unit is
on the instrument panel. This control allows the
driver to set the rear compartment fan speed, to turn
the rear unit off, or to give control to the intermedi-
ate seat occupants by switching to the REAR posi-
tion. When the rear unit is controlled from the
instrument panel, rear air temperature is based on
the driver-side temperature control position, and the
mode (floor or overhead air) is based on the front
control's mode position.
²The mode control knob enables continously vari-
able proportioning of air flow between modes but has
detents adjacent to each icon.
²The blower control provides five separate speeds
and Off. When the fan is off, the HVAC computer
closes the recirculation door to prevent outside air
from entering the passenger compartment.
²Interior air may be recirculated to speed up
heating or cooling in all modes exccept defrost and
mix by pressing the Recirculate button on the control
panel.
²To reduce humidity for rapid defogging the A/C
compressor runs automatically in modes from ªmix'
to full defrost when outside temperatures are above
freezing.
²Air conditioning is available in any mode by
pressing the snowflake, A/C on/off, button.
RSHEATING & AIR CONDITIONING24-3
HEATING & AIR CONDITIONING (Continued)
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