1998 ISUZU TROOPER fuse box

5C – 10 POWER ASSISTED BRAKE SYSTEM
BLEEDING BRAKE HYDRAULIC SYSTEM
A bleeding operation is necessary to remove air from
the hydraulic brake system whenever air is introduced
into the hydraulic system. It may be necessary to
bleed the hydraulic system at all four brakes if air has
been introduced through a low fluid level or by
disconnecting brake pipes at the master cylinder. If a
brake pipe is disconneted at one wheel, only that
wheel cylinder/caliper needs to be bled. If pipes are
disconnected at any fitting located between master
cylinder and brakes, then the brake system served by
the disconnected pipe must be bled.
1. For 4-wheel Antilock Brake System (ABS)
equipped vehicle, be sure to remove the ABS main
fuse 40A located at the relay and fuse box before
bleeding air. If you attempt to bleed air without
removing the main fuse, air cannot be let out
thoroughly, and this may cause damage to the
hydraulic unit. After bleeding air, be sure to
replace the ABS main fuse back to its original
position.
2. Set the parking brake completely, then start the
engine.
NOTE:
The vacuum booster will be damaged if the bleeding
operation is performed with the engine off.
3. Remove the master cylinder reservoir cap.
4. Fill the master cylinder reservoir with brake fluid.
Keep the reservoir at least half full during the air
bleeding operation.
5. Always use new brake fluid for replenishment.
6. In replenishing brake fluid, take care that air
bubbles do not enter the brake fluid.
•When the master cylinder is replaced or
overhauled, first bleed the air from the master
cylinder, then from each wheel cylinder and
caliper following the procedures described
below.
Bleeding the Master Cylinder
7. Disconnect the rear wheel brake pipe 1from the
master cylinder. Check the fluid level and
replenish as necessary. If replenished, leave the
system for at least one minute.
8. Depress the brake pedal slowly once and hold it
depressed.
9. Completely seal the delivery port of the master
cylinder where the pipe was disconnected with
your finger, then release the brake pedal slowly.
10. Release your finger from the delivery port when
the brake pedal returns completely.
11. Repeat steps 7 through 9 until the brake fluid
comes out of the delivery port during step 7.
NOTE:
Do not allow the fluid level in the reservoir to go
below the half-way mark.
21

6A±5
ENGINE MECHANICAL
4. Engine Lacks Compression
Condition
Possible causeCorrection
Engine lacks compressionSpark plug loosely fitted or spark
plug gasket defectiveTighten to specified torque or replace
gasket
Valve timing incorrectAdjust
Cylinder head gasket defectiveReplace gasket
Valve incorrectly seatedLap valve
Valve stem seizedReplace valve and valve guide
Valve spring weakened or brokenReplace
Cylinder or piston rings wornOverhaul engine
Piston ring seizedOverhaul engine.
Engine Compression Test Procedure
1. Start and run the engine until the engine reaches
normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and fuse
box.
6. Engage the starter and check that the cranking speed
is approximately 300 rpm.7. Install cylinder compression gauge into spark plug
hole.
8. With the throttle valve opened fully, keep the starter
engaged until the compression gage needle reaches
the maximum level. Note the reading.
9. Repeat the test with each cylinder.
If the compression pressure obtained falls below the
limit, engine overhaul is necessary.
Limit; 1000 kPa (145 psi)

6E±29 ENGINE DRIVEABILITY AND EMISSIONS
Engine Component Locator Table
Number
NameLocation
1Linear Exhaust Gas Recirculation (EGR) ValveRear right side of the engine
2Throttle Position (TP) SensorOn the rear of the throttle body
3Intake Air Temperature (IAT) SensorOn the intake air duct near the throttle body
4Check Engine (MIL) LightOn the instrument panel beneath the
tachometer
5Positive Crankcase Ventilation (PCV) ValveOn the left of the cylinder head cover
6Air CleanerLeft front of the engine bay
7Mass Air Flow (MAF) SensorAttached to the air filter box
8Camshaft Position (CMP) SensorOn the rear right side at the left of the cylinder
head cover
9Fuel Pressure RegulatorRear right side of the engine
10Idle Air Control (IAC) ValveOn the left of the throttle body
11Upper Intake ManifoldTop of the engine
12Fuse/Relay BoxAlong the inside of the right fender
13Manifold Absolute Pressure (MAP) SensorBolted to the top of the upper intake manifold
14Throttle BodyBetween the intake air duct and the upper
intake manifold
15Engine Coolant Temperature SensorOn the coolant crossover pipe at the front of
the engine, near the throttle body

6E±31 ENGINE DRIVEABILITY AND EMISSIONS
Engine Component Locator Table
Number
NameLocation
1Linear Exhaust Gas Recirculation (EGR) ValveRear right side of the engine
2Throttle Position (TP) SensorOn the rear of the throttle body
3Intake Air Temperature (IAT) SensorOn the intake air duct near the throttle body
4Check Engine (MIL) LightOn the instrument panel beneath the
tachometer
5Positive Crankcase Ventilation (PCV) ValveOn the left of the cylinder head cover
6Air CleanerLeft front of the engine bay
7Mass Air Flow (MAF) SensorAttached to the air filter box
8Camshaft Position (CMP) SensorOn the rear right side at the left of the cylinder
head cover
9Fuel Pressure RegulatorRear right side of the engine
10Idle Air Control (IAC) ValveOn the left of the throttle body
11Upper Intake ManifoldTop of the engine
12Fuse/Relay BoxAlong the inside of the right fender
13Manifold Absolute Pressure (MAP) SensorBolted to the top of the upper intake manifold
14Throttle BodyBetween the intake air duct and the upper
intake manifold
15Engine Coolant Temperature SensorOn the coolant crossover pipe at the front of
the engine, near the throttle body

6E±56
ENGINE DRIVEABILITY AND EMISSIONS
A/C Clutch Control Circuit Diagnosis

 
StepNo Ye s Value(s) Action
61. Engine idling.
2. A/C ªONº.
3. Blower ªONº.
4. Observe the ªA/C Requestº display on the Tech 2.
Does the tool ªA/C Requestº display indicate ªYes?º
ÐGo to Step 34Go to Step 7
7Temporarily substitute the A/C compressor relay in
place of the A/C thermostat relay, then repeat Step 5.
Did the ªA/C Requestº display indicate ªYes?º
ÐGo to Step 8Go to Step 9
8Replace the original A/C thermostat relay.
Is the action complete?
ÐVerify repairÐ
9Dose the blower operate?ÐGo to Step 10Go to Step 11
10Repair the blower.
Is the action complete?
ÐVerify repairÐ
11Check for a faulty 10a A/C fuse in the underdash fuse
panel.
Was the 10A fuse OK?
ÐGo to Step 13Go to Step 12
12Check for short circuit and make repairs if necessary.
Replace the 10A A/C fuse.
Is the action complete?
ÐVerify repairÐ
131. Ignition ªON.º
2. Use a DVM to check voltage at the positive A/C
switch wire (BRN).
Was voltage equal to the specified value?
+BGo to Step 15Go to Step 14
14Repair the open wire (BRN) between the A/C switch
and the A/C fuse.
Is the action complete?
ÐVerify repairÐ
151. Remove the glove box to gain access to the A/C
thermostat.
2. Disconnect the thermostat connector.
3. Attach a fused jumper between ground and the
PNK/GRN wire at the thermostat.
4. A/C ªON.º
5. Blower ªON.º
Dose A/C request indicate ªYESº on the Tech 2?
ÐGo to Step 16Go to Step 23
161. Ignition ªON.º
2. Use a DVM to check voltage at the electronic A/C
thermostat.
Was voltage equal to the specified value?
+BGo to Step 20Go to Step 17
17Check for an open (LT GRN) between the thermostat
and the A/C switch.
Was the wire open?
ÐGo to Step 18Go to Step 19
18Repair the open wire (LT GRN) between the thermostat
and the A/C switch.
Is the action complete?
ÐVerify repairÐ

6E±81 ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Check the 15 A ignition coil fuse, the 15 A engine fuse,
and the 30 A PCM fuse.
Was a fuse blown?
ÐGo to Step 3Go to Step 4
3Check for a short to ground and replace the fuse.
Is the action complete?
ÐVerify repairÐ
41. Ignition ªOFF,º install a fuel pressure gauge at the
test fitting on the fuel supply line in the engine
compartment. (Use a shop cloth to absorb any fuel
leakage while making the connection.)
2. Ignition ªON,º observe the fuel pressure.
Is the fuel pressure within the specified values, and
does it hold steady?
285-376 kPa
(43-55 psi)
Go to Step 6Go to Step 5
5Is any fuel pressure indicated?
Ð
Go to Fuel
System
Electrical TestGo to Fuel
System
Diagnosis
6Install an injector switch box to the injector test
connector, and attempt to operate the injector.
Did the fuel pressure drop when the injector is
operated?
ÐGo to Step 7Go to Step 12
7Install an injector test light at the #2 cylinder injector
harness connector.
Does the light blink when the engine is cranked?
ÐGo to Step 8Go to Step 18
81. Ignition ªON.º
2. While the coil connectors are disconnected, touch
each coil connector's ignition feed terminal with a
grounded test light (the ignition feed wire is black
with orange tracer).
Did the test light illuminate?
ÐGo to Step 10Go to Step 9
9Repair the open ignition feed circuit.
Is the action complete?
ÐVerify repairÐ
10While the coil connectors are disconnected, touch
each connector's secondary ground terminal with a
test light to B+. (The ground wires are black.)
Did the test light illuminate at each coil connector?
ÐGo to Step 12Go to Step 11
11Repair the open secondary ground circuit.
Is the action complete?
ÐVerify repairÐ
121. Test the fuel for contamination.
2. If a problem is found, clean the fuel system and
correct the contaminated fuel condition as
necessary. Replace the fuel filter and replace any
injectors that are not delivering fuel (see Injector
Balance Test).
Was a problem found?
ÐVerify repairGo to Step 13

6E±319 ENGINE DRIVEABILITY AND EMISSIONS
Fuel Pump Relay
Removal Procedure
1. Remove the fuse and relay box cover from under the
hood.
2. Consult the diagram on the cover to determine which
is the correct relay.
3. Insert a small screwdriver into the catch slot on the
forward side of the fuel pump relay.

The screwdriver blade will release the catch inside.
T321092
4. Pull the relay straight up and out of the fuse and relay
box.
TS23976R
Installation Procedure
1. Insert the relay into the correct place in the fuse and
relay box with the catch slot facing forward.
2. Press down until the catch engages.

An audible ªclickº will be heard.
T321092
3. Install the fuse and relay box cover.
Fuel Rail Assembly
Removal Procedure
NOTE:

Do not attempt to remove the fuel inlet fitting on the
fuel rail. It is staked in place. Removing the fuel inlet
fitting will result in damage to the fuel rail or the
internal O-ring seal.

Use care when removing the fuel rail assembly in
order to prevent damage to the injector electrical
connector terminals and the injector spray tips.

Fittings should be capped and holes plugged during
servicing to prevent dirt and other contaminants from
entering open lines and passages.

6E±325 ENGINE DRIVEABILITY AND EMISSIONS
Spark Plug Gap Check

Check the gap of all spark plugs before installation.

Use a round wire feeler gauge to ensure an accurate
check.

Plugs installed with the wrong gap can cause poor
engine performance and excessive emissions.
Installation Procedure
NOTE: The plug must thread smoothly into the cylinder
head and be fully seated. Use a thread chaser if
necessary to clean the threads in the cylinder head.
Cross-threading or failure to fully seat the spark plug can
cause plug overheating, exhaust blow-by gas, or thread
damage. Do not overtighten the spark plugs. Over
tightening can cause aluminum threads to strip.
1. Install the spark plug in the engine. Use the
appropriate spark plug socket.
Tighten

Tighten the spark plug to 18 N´m (13 lb ft.).
2. Install the ignition coil and spark plug boot over the
spark plug.
014RW108
3. Secure the ignition coil to the rocker cover with two
screws.
014RW091
4. Connect the electrical connector at the ignition coil.
5. Connect the negative battery cable.
Catalytic Converter
Removal and Installation Procedure
Refer to Engine Exhaust in Engine.
Air Conditioning Relay
Removal Procedure
1. Remove the fuse and relay box cover from under the
hood.
2. Consult the diagram on the cover to determine which
is the correct relay.
3. Insert a small screwdriver into the catch slot on the
forward side of the fuel pump relay.

The screwdriver blade will release the catch inside.
T321092