
6E±339 ENGINE DRIVEABILITY AND EMISSIONS
0005
PCM Components
The PCM is designed to maintain exhaust emission levels
to government mandated standards while providing
excellent driveability and fuel efficiency. The PCM
monitors numerous engine and vehicle functions via
electronic sensors such as the throttle position (TP)
sensor, heated oxygen sensor (HO2S), and vehicle
speed sensor (VSS). The PCM also controls certain
engine operations through the following:
Fuel injector control
Ignition control module
Knock sensor
Automatic transmission shift functions
Cruise control
A/C clutch control
PCM Voltage Description
The PCM supplies a buffered voltage to various switches
and sensors. It can do this because resistance in the
PCM is so high in value that a test light may not illuminate
when connected to the circuit. An ordinary shop
voltmeter may not give an accurate reading because the
voltmeter input impedance is too low. Use a 10-megohm
input impedance digital voltmeter (such as J 39200) to
assure accurate voltage readings.
The input/output devices in the PCM include
analog-to-digital converters, signal buffers, counters,
and special drivers. The PCM controls most components
with electronic switches which complete a ground circuit
when turned ªON.º These switches are arranged in
groups of 4 and 7, called either a surface-mounted quad
driver module (QDM), which can independently control up
to 4 output terminals, or QDMs which can independently
control up to 7 outputs. Not all outputs are always used.
PCM Input/Outputs
Inputs ± Operating Conditions Read
Air Conditioning ªONº or ªOFFº Engine Coolant Temperature
Crankshaft Position
Exhaust Oxygen Content
Electronic Ignition
Manifold Absolute Pressure
Battery Voltage
Throttle Position
Vehicle Speed
Fuel Pump Voltage
Power Steering Pressure
Intake Air Temperature
Mass Air Flow
Engine Knock
Camshaft Position
Outputs ± Systems Controlled
Exhaust Gas Recirculation (EGR)
Ignition Control
Fuel Control
Idle Air Control
Electric Fuel Pump
Air Conditioning
Diagnostics
± Malfunction Indicator Lamp (Service Engine Soon
lamp)
± Data Link Connector (DLC)
± Data Output
Transmission Control Module
Alternator Gain Control
PCM Service Precautions
The PCM is designed to withstand normal current draws
associated with vehicle operation. Avoid overloading any
circuit. When testing for opens and shorts, do not ground
or apply voltage to any of the PCM's circuits unless
instructed to do so. These circuits should only be tested
Tech-2. The PCM should remain connected to the PCM
or to a recommended breakout box.
Reprogramming The PCM
The Trooper allow reprogramming of the PCM without
removing it from the vehicle . This provides a flexible and
cost-effective method of making changes in software
calibrations.
The service programming system (SPS) will not allow
incorrect software programming or incorrect calibration
changes.
Refer to the UBS 98model year Immobilizer Workshop
Manual.
Throttle Position (TP) Sensor
The throttle position (TP) sensor is a potentiometer
connected to the throttle shaft on the throttle body. The
PCM monitors the voltage on the signal line and
calculates throttle position. As the throttle valve angle is
changed (accelerator pedal moved), the TP sensor signal
also changes. At a closed throttle position, the output of

6E±341 ENGINE DRIVEABILITY AND EMISSIONS
this is done, if the problem still exists, it may be diagnosed
in the normal manner.
Electrostatic Discharge Damage
Electronic components used in the PCM are often
designed to carry very low voltage. Electronic
components are susceptible to damage caused by
electrostatic discharge. Less than 100 volts of static
electricity can cause damage to some electronic
components. By comparison, it takes as much as 4000
volts for a person to feel even the zap of a static
discharge.
TS23793
There are several ways for a person to become statically
charged. The most common methods of charging are by
friction and induction.
An example of charging by friction is a person sliding
across a vehicle seat.
Charge by induction occurs when a person with well
insulated shoes stands near a highly charged object
and momentary touches ground. Charges of the
same polarity are drained off leaving the person
highly charged with the opposite polarity. Static
charges can cause damage, therefore it is important
to use care when handling and testing electronic
components.
NOTE: To p r e ve n t p ossible electrostatic discharge
damage, follow these guidelines:
Do not touch the PCM connector pins or soldered
components on the PCM circuit board.
Do not touch the knock sensor module component
leads.
Do not open the replacement part package until the
part is ready to be installed.
Before removing the part from the package, ground
the package to a known good ground on the vehicle.
If the part has been handled while sliding across the
seat, while sitting down from a standing position, or
while walking a distance, touch a known good ground
before installing the part.
Upshift Lamp
Refer to Manual Transmission.
General Description (Air Induction)
Air Induction System
The air induction system filters contaminants from the
outside air, and directs the progress of the air as it is
drawn into the engine. A remote-mounted air cleaner
prevents dirt and debris in the air from entering the
engine. The air duct assembly routes filtered air to the
throttle body. Air enters the engine by to following steps:
1. Through the throttle body.
2. Into the common chamber.
3. Through the cylinder head intake ports.
4. Into the cylinders.
055RV010
General Description (Fuel Metering)
Acceleration Mode
The PCM provides extra fuel when it detects a rapid
increase in the throttle position and the air flow.
Accelerator Controls
The accelerator control system is a cable-type system
with specific linkage adjustments.
Refer to
Cable Adjustment.
Battery Voltage Correction Mode
When battery voltage is low, the PCM will compensate for
the weak spark by increasing the following:
The amount of fuel delivered.
The idle RPM.
Ignition dwell time.
CMP Signal
The PCM uses this signal to determine the position of the
number 1 piston during its power stroke, allowing the

6H±3 ENGINE SPEED CONTROL SYSTEM
Accelerator Pedal
Accelerator Pedal and Associated
Parts
035RW028
Legend
(1) Accelerator Pedal Control Cable
(2) Accelerator Pedal Assembly
Removal
1. Accelerator Pedal control cable(1).
2. Accelerator Pedal assembly(2).
Installation
1. Accelerator pedal assembly(2).
2. Accelerator pedal control cable(1).
Adjustment
Manual Transmission:
Rotate counterclockwise to loosen the lock nut and
screw the stopper bolt in sufficiently.
Fully depress the pedal and hold it there with your
hand. Next, rotate the stopper bolt until it hits the
stopper of pedal bracket. Then, lock the stopper bolt
there.
Automatic Transmission:
Rotate counterclockwise to loosen the kickdown
switch sufficiently.
Fully depress the pedal and hold it there with your
hand. Rotate the switch clockwise and then rotate
further by 1/2 turn from the position where the switch
clicks. Lock the switch there.
Step on the accelerator pedal and make sure that you
can hear a clicking sound at the full stroke position.

FUEL SYSTEM 6C Ð 23
ACCELERATOR PEDAL
Installation Steps
To install, follow the removal steps in the
reverse order.
Removal Steps
1. Accelerator control cable
2. Accelerator pedal assembly
REMOVAL
1. Accelerator Control Cable
2. Accelerator Pedal Assembly
INSTALLATION
2. Accelerator Pedal Assembly
1. Accelerator Control Cable
Adjustment of Pedal Stroke
Manual Transmission
·Turn counterclockwise and loosen the stopper bolts
sufficiently.
·Step on the pedal fully and hold it with your hand.
Next turn the stopper bolt until it comes into contact
with the stopper of pedal bracket. Then, lock the
stopper bolt in that position.

ENGINE ELECTRICAL 6D1 Ð 3
BATTERY CHARGING
Observe the following safety precautions when
charging the battery:
1. Never attempt to charge the battery when the
fluid level is below the lower level line on the
side of the battery. In this case, the battery
must be replaced.
2. Pay close attention to the battery during the
charging procedure.
Battery charging should be discontinued or the
rate of charge reduced if the battery feels hot to
the touch.
Battery charging should be discontinued or the
rate of charge reduced if the battery begins to
gas or spew electrolyte from the vent holes.
3. In order to more easily view the hydrometer
blue dot or ring, it may be necessary to jiggle or
tilt the battery.
4. Battery temperature can have a great effect on
battery charging capacity.
5. The sealed battery used on this vehicle may be
either quick-charged or slow-charged in the
same manner as other batteries.
Whichever method you decide to use, be sure
that you completely charge the battery. Never
partially charge the battery.
JUMP STARTING
JUMP STARTING WITH AN AUXILIARY
(BOOSTER) BATTERY
CAUTION:
Never push or tow the vehicle in an attempt to
start it. Serious damage to the emission system
as well as other vehicle parts will result.
Treat both the discharged battery and the
booster battery with great care when using
jumper cables. Carefully follow the jump
starting procedure, being careful at all times to
avoid sparking.
WARNING:
Failure to carefully follow the jump starting
procedure could result in the following:
1. Serious personal injury, particulaly to
your eyes.
2. Property damage from a battery explo-
sion, battery acid, or an electrical fire.
3. Damage to the electronic components of
one or both vehicles particularly. Never expose the battery to an open flame or elec-
trical spark. Gas generated by the battery may catch
fire or explode.
Remove any rings, watches, or other jewelry before
working around the battery. Protect your eyes by
wearing an approved set of goggles.
Never allow battery fluid to come in contact with
your eyes or skin.
Never allow battery fluid to come in contact with
fabrics or painted surfaces.
Battery fluid is a highly corrosive acid.
Should battery fluid come in contact with your
eyes, skin, fabric, or a painted surface, immediately
and thoroughly rinse the affected area with clean
tap water.
Never allow metal tools or jumper cables to come
in contact with the positive battery terminal, or any
other metal surface of the vehicle. This will protect
against a short circuit.
Always keep batteries out of the reach of young
children.
JUMP STARTING PROCEDURE
1. Set the vehicle parking brake.
If the vehicle is equipped with an automatic
transmission, place the selector lever in the
ÒPARKÓ position.
If the vehicle is equipped with a manual trans-
mission place the shift lever in the ÒNEUTRALÓ
position.
Turn ÒOFFÓ the ignition.
Turn ÒOFFÓ all lights and any other accessory
requiring electrical power.
2. Look at the built-in hydrometer.
If the indication area of the built-in hydrometer
is completely clear, do not try to jump start.
3. Attach the end of one jumper cable to the posi-
tive terminal of the booster battery.
Attach the other end of the same cable to the
positive terminal of the discharged battery.
Do not allow the vehicles to touch each other.
This will cause a ground connection, effectively
neutralizing the charging procedure.
Be sure that the booster battery has a 12 volt
rating.
4. Attach one end of the remaining cable to the
negative terminal of the booster battery.
Attach the other end of the same cable to a
solid engine ground (such as the A/C com-
pressor bracket or the generator mounting
bracket) of the vehicle with the discharged bat-
tery.
This ground connection must be at least 450
mm (18 in) from the battery of the vehicle
whose battery is being charged.
ON-VEHICLE SERVICE

ENGINE MECHANICAL 6A – 29
13 Vacuum Hose
1) Disconnect vacuum hose from vacuum pump.
14. Starter Harness
1) Disconnect B terminal and put cable harness
close to chassis side.
2) Disconnect S terminal connector.
15. Engine Harness
1) Disconnect engine harness close to engine side.
16. Fuel Pipe
1) Remove fuel pipe from fuel pump and take care
not to spill fuel and let dust enter.
17. Engine Ground Cable
1) Disconnect ground cable from left rear side of
timing gear case.
18. Vacuum Hose: Vacuum Tank
Disconnect vacuum hose from vacuum pump side.
19. Glow Plug Harness
20. Transmission Assembly
1) Set transmission support tool under the
transmission.
2) Remove transmission rear mount.
3) Remove transmission fixing bolt from rear of
engine assembly except two bolts.
4) Carefully hang up engine assembly with a hoist.
5) Remove remaining two transmission fixing bolts.
6) Remove transmission assembly.
7) Remove heater hose.
8) Disconnect wire harness connector for shift on
the fly.
9) Remove vacuum hose.
21. Prepare Engine Stand
22. Engine Assembly
1) Remove engine mount fixing bolts.
2) Carefully hang up the engine assembly.
3) Take out the engine assembly making sure not
to damage the brake oil pipe and other pipe etc.
INSTALLATION
1. Engine assembly
1) Install engine in mounting position by using
hoist.
2. Transmission Assembly
1) Refer to transmission installation steps in
section 7.
3. Engine Mounting
1) After all fixing bolts (left: two bolts, rights: two
bolts) were inserted in every hole, tighten fixing
bolts to the specified torque.
Torque: 40 N·m (4 kg·m/29 lb·ft)
4. Glow Plug Harness
5. Vacuum Hose
1) Connect Vacuum Hose to Vacuum Pump
6. Engine Ground Cable
7. Fuel Pipe
1) Install fuel pipe to fuel pump.
8. Engine Harness
9. Starter Harness
10. A/C Compressor Assembly
1) Tighten temporarily the fixing bolts (upper and
front lower sides of compressor.)2) Tighten fixing bolt (rear under side of
compressor) to the specified torque.
3) Tighten fixing bolts (front upper and lower sides
of compressor) to the specified torque.
Torque: 40 N·m (4 kg·m/29 lb·ft)
Legend
(1) Tensioner
(2) Bolt
(3) Bracket
(4) A/C compressor
(5) Bolt
11. A.C Generator Harness
12. Engine Ground Cable
1) Tighten ground cable to A/C compressor
bracket.
13. Air Cleaner cover & Duct
14. Intercooler Assembly
1) Refer to “Intercooler” in this manual.
15. Radiator Assembly
1) Install rubber cushion in under left and right part
of radiator and position radiator.
2) Fix radiator with bracket.
16. Cooling Fan Assembly
1) Install cooling fan assembly and tighten fixing
bolts to the specified torque.
Torque: 8 N·m (0.8 kg·m/5.8 lb ft)
17. Fan Shroud
18. Radiator Hose
1) Connect upper and lower hose to engine side.
2) Pour coolant into radiator.
19. Install battery.
20. Connect window washer hose and install engine
hood.
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3
4
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