1998 ISUZU TROOPER Remove engine

6D3±19 STARTING AND CHARGING SYSTEM
Generator
Removal
1. Disconnect battery ground cable.
2. Move drive belt tensioner to loose side using wrench
then remove drive belt (1).
3. Disconnect the wire from terminal ªBº and disconnect
the connector (4).
4. Remove generator fixing bolt (3).
5. Remove generator assembly (2).
060RW002
Inspection
1. Disconnect the wiring connector from generator.
2. With the engine stopped, turn starter switch to ªONº
and connect a voltmeter between connector terminal
L (2) and ground or between terminal IG (1) and
ground.
066RW001If voltage is not present, the line between battery and
connector is disconnected and so requires repair.
3. Reconnect the wiring connector to the generator, run
the engine at middle speed, and turn off all electrical
devices other than engine.
4. Measure battery voltage. If it exceeds 16V, repair or
replace the generator.
5. Connect an ammeter to output terminal of generator,
and measure output current under load by turning on
the other electrical devices (eg., head lights). At this
time, the voltage must not be less than 13V.
Installation
1. Install generator assembly to the position to be
installed.
2. Install generator assembly and tighten the fixing bolts
to the specified torque.
Torque:
M10 bolt: 41 N´m (4.2 Kg´m/30 lb ft)
M8 bolt: 21 N´m (2.1 Kg´m/15 lb ft)
3. Connect wiring harness connector and direct terminal
ªBº.
4. Move drive belt tensioner to loose side using wrench,
then install drive belt to normal position.
5. Reconnect battery ground cable.

6E±43 ENGINE DRIVEABILITY AND EMISSIONS
Tech 2
From 98 MY, Isuzu dealer service departments are
recommended to use Tech 2. Please refer to Tech 2 Tech
2 user guide.
901RW180
Legend
(1) PCMCIA Card
(2) RS 232 Loop Back Connector(3) SAE 16/19 Adaptor
(4) DLC Cable
(5) Tech±2
Tech 2 Features
1. Tech 2 is 12 volt system. Do not apply 24 volt.
2. After connect and/or install Tech 2 body, Vehicle
Communications Interface (VCI) module, PCMCIA
card and DLC connector, connect them to the vehicle
DLC.
3. After power off to the Tech 2, remove and reinstall the
PCMCIA card.
4. The PCMCIA card has a capacity of 10 Megabytes
which is 10 times greater than the memory of the Tech
1 Mass Storage Cartridge.5. The Tech 2 has the capability of two snapshots.
6. The PCMCIA card is sensitive to magnetism and
static electricity, so care should be taken in the
handling of the card.
7. The Tech 2 can plot a graph when replaying a
snapshot.
8. Always return to the Main Menu to press EXIT key
several times before shutting down.
9. To clear Diagnostic Trouble Codes (DTCs), open
Application Menu and press ªF1: Clear DTC Infoº.

6E±46
ENGINE DRIVEABILITY AND EMISSIONS
060RW223
The following is a brief description of each of the sub
menus in DTC Info and Specific DTC. The order in which
they appear here is alphabetical and not necessarily the
way they will appear on the Tech 2.
DTC Information Mode
Use the DTC info mode to search for a specific type of
stored DTC information. There are seven choices. The
service manual may instruct the technician to test for
DTCs in a certain manner. Always follow published
service procedures.
To get a complete description of any status, press the
ªEnterº key before pressing the desired F-key. For
example, pressing ªEnterº then an F-key will display a
definition of the abbreviated Tech 2 status.
060RW221
DTC Status
This selection will display any DTCs that have not run
during the current ignition cycle or have reported a test
failure during this ignition up to a maximum of 33 DTCs.
DTC tests which run and pass will cause that DTC
number to be removed from Tech 2 screen.Fail This Ignition
This selection will display all DTCs that have failed during
the present ignition cycle.
History
This selection will display only DTCs that are stored in the
PCM's history memory. It will not display Type B DTCs
that have not requested the MIL (ªCheck Engineº lamp). It
will display all type A and B DTCs that have requested the
MIL and have failed within the last 40 warm-up cycles. In
addition, it will display all type C and type D DTCs that
have failed within the last 40 warm-up cycles.
Last Test Failed
This selection will display only DTCs that have failed the
last time the test ran. The last test may have run during a
previous ignition cycle if a type A or type B DTC is
displayed. For type C and type D DTCs, the last failure
must have occurred during the current ignition cycle to
appear as Last Test Fail.
MILSVC or Message Requested
This selection will display only DTCs that are requesting
the MIL. Type C and type D DTCs cannot be displayed
using this option. This selection will report type B DTCs
only after the MIL has been requested.
Not Run Since Code Clear
This option will display up to 33 DTCs that have not run
since the DTCs were last cleared. Since any displayed
DTCs have not run, their condition (passing or failing) is
unknown.
Test Failed Since Code Clear
This selection will display all active and history DTCs that
have reported a test failure since the last time DTCs were
cleared. DTCs that last failed more than 40 warm-up
cycles before this option is selected will not be displayed.
Injector Balance Test
This test is conducted to make it sure that appropriate
electric signals are being sent to injectors Nos. 1±6.
Tech 2 must be used for this test.
Test Procedure:
1. Connect Tech 2 to the vehicle DLC.
2. Run the Engine at idle.

6E±54
ENGINE DRIVEABILITY AND EMISSIONS
A/C Clutch Control Circuit Diagnosis
D06RW085
Circuit Description
When air conditioning and blower fan are selected, and if
the system has a sufficient refrigerant charge, a 12-volt
signal is supplied to the A/C request input of the
powertrain control module (PCM). The A/C request
signal may be temporarily canceled during system
operation by the electronic thermostat in the evaporator
case. The electronic thermostat may intermittently
remove the control circuit ground for the A/C thermostat
relay to prevent the evaporator from forming ice. When
the A/C request signal is received by the PCM, the PCM
supplies a ground from the compressor clutch relay if the
engine operating conditions are within acceptable
ranges. With the A/C compressor relay energized,
voltage is supplied to the compressor clutch coil.
The PCM will enable the compressor clutch to engage
whenever A/C has been selected with the engine running,
unless any of the following conditions are present:
The throttle is greater than 90%.

The ignition voltage is below 10.5 volts.

The engine speed is greater than 4500 RPM for 5
seconds or 5400 RPM.

The engine coolant temperature (ECT) is greater than
125
C (257
F).

The intake air temperature (IAT) is less than 5
C
(41
F).

The power steering pressure switch signals a cramped
position.
Diagnostic Aids
To diagnose an the intermittent fault, check for the
following conditions:

Poor connection at the PCM±Inspect connections for
backed-out terminals, improper mating, broken locks,
improperly formed or damaged terminals, and poor
terminal-to-wire connection.

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±58
ENGINE DRIVEABILITY AND EMISSIONS
A/C Clutch Control Circuit Diagnosis

 
StepNo Ye s Value(s) Action
341. Remove the A/C compressor relay.
2. Ignition ªON.º
3. Use a DVM to check voltage at both of the BRN
wires at the A/C compressor relay socket.
Is the voltage equal to the specified value?
+BGo to Step 36Go to Step 35
35Repair the faulty BRN wire between the A/C fuse and
the A/C compressor relay .
Is the action complete?
ÐVerify repairÐ
361. A/C compressor relay removed.
2. Engine idling.
3. A/C ªON.º
4. Blower ªON.º
5. Use a DVM to measure voltage between the
GRN/BLK wire at the A/C compressor relay socket
and battery+.
Did the DVM indicate the specified value?
+BGo to Step 40Go to Step 37
37Check for an open GRN/BLK wire between PCM
terminal B-14 and the A/C compressor relay.
Was the wire open?
ÐGo to Step 38Go to Step 39
38Repair the open GRN/BLK wire between the PCM and
the A/C compressor relay.
Is the action complete?
ÐVerify repairÐ
39Check for a damaged pin or terminal at B-14 of the
PCM.
Was a damaged pin or a terminal found?
ÐGo to Step 32Go to Step 33
401. A/C compressor relay removed.
2. Connect a fused jumper at the A/C compressor
relay socket between either BRN wire and the
BRN/YEL wire.
3. Engine idling.
4. A/C ªON.º
5. Blower ªON.º
Did the compressor magnetic clutch engage?
ÐGo to Step 41Go to Step 42
41Repair the A/C compressor relay.
Is the action complete?
ÐVerify repairÐ
42Check for an open circuit between the A/C compressor
relay and the A/C clutch.
Was an open circuit found?
ÐGo to Step 43Go to Step 44
43Repair the open circuit between the compressor Clutch
and the A/C compressor relay.
Is the action complete?
ÐVerify repairÐ
44Service the compressor clutch or replace the
compressor due to a faulty internal overheat switch.
Is the action complete?
ÐVerify repairÐ

6E±59 ENGINE DRIVEABILITY AND EMISSIONS
A/C Clutch Control Circuit Diagnosis

 
StepNo Ye s Value(s) Action
451. Remove the A/C compressor relay.
2. Idle the engine.
Is the compressor clutch still engaged when A/C is not
selected?
ÐGo to Step 46Go to Step 47
46Repair the short to voltage between the A/C clutch and
A/C compressor relay.
Is the action complete?
ÐVerify repairÐ
471. Reinstall the A/C compressor relay.
2. Remove the A/C thermostat relay.
3. Engine idling.
Is the compressor clutch still engaged when A/C is not
selected?
ÐGo to Step 48Go to Step 50
48Use a DVM to check for a short to ground between the
A/C compressor relay and B-14 of the PCM.
Was a short detected?
ÐGo to Step 49Go to Step 33
49Repair the short to ground between the PCM and A/C
compressor relay.
Is the action complete?
ÐVerify repairÐ
50Repair the short to ground between the A/C thermostat
relay and the electronic thermostat.
Is the action complete?
ÐVerify repairÐ

6E±65 ENGINE DRIVEABILITY AND EMISSIONS
Knock Sensor Diagnosis
The Tech 2 has two data displays available for diagnosing
the knock sensor (KS) system. The two displays are
described as follows:

ªKnock Retardº indicates the number of degrees that
the spark timing is being retarded due to a knock
condition.

ªKS Noise Channelº indicates the current voltage level
being monitored on the noise channel.
DTCs P0325 and P0327 are designed to diagnose the KS
module, the knock sensor, and the related wiring. The
problems encountered with the KS system should set a
DTC. However, if no DTC was set but the KS system is
suspect because of a detonation complaint, refer to
Detonation/Spark Knock in Symptoms.
Powertrain Control Module (PCM)
Diagnosis
To read and clear diagnostic trouble codes, use a Tech 2.
IMPORTANT:Use of a Tech 2 is recommended to clear
diagnostic trouble codes from the PCM memory.
Diagnostic trouble codes can also be cleared by turning
the ignition ªOFFº and disconnecting the battery power
from the PCM for 30 seconds. Turning off the ignition and
disconnecting the battery power from the PCM will cause
all diagnostic information in the PCM memory to be
cleared. Therefore, all the diagnostic tests will have to be
re-run.
Since the PCM can have a failure which may affect only
one circuit, following the diagnostic procedures in this
section will determine which circuit has a problem and
where it is.
If a diagnostic chart indicates that the PCM connections
or the PCM is the cause of a problem, and the PCM is
replaced, but this does not correct the problem, one of the
following may be the reason:

There is a problem with the PCM terminal connections.
The terminals may have to be removed from the
connector in order to check them properly.

The problem is intermittent. This means that the
problem is not present at the time the system is being
checked. In this case, refer to the
Symptoms portion of
the manual and make a careful physical inspection of
all component and wiring associated with the affected
system.

There is a shorted solenoid, relay coil, or harness.
Solenoids and relays are turned ªONº and ªOFFº by the
PCM using internal electronic switches called drivers.
A shorted solenoid, relay coil, or harness will not
damage the PCM but will cause the solenoid or relay to
be inoperative.
Multiple PCM Information Sensor
DTCS Set
Circuit Description
The powertrain control module (PCM) monitors various
sensors to determine the engine operating conditions.
The PCM controls fuel delivery, spark advance,
transmission operation, and emission control device
operation based on the sensor inputs.The PCM provides a sensor ground to all of the sensors.
The PCM applies 5 volts through a pull-up resistor, and
determines the status of the following sensors by
monitoring the voltage present between the 5-volt supply
and the resistor:

The engine coolant temperature (ETC) sensor

The intake air temperature (IAT) sensor

The transmission fluid temperature (TFT) sensor
The PCM provides the following sensors with a 5-volt
reference and a sensor ground signal:

The exhaust gas recirculating (EGR) pintle position
sensor

The throttle position (TP) sensor

The manifold absolute pressure (MAP) sensor
The PCM monitors the separate feedback signals from
these sensors in order to determine their operating
status.
Diagnostic Aids
IMPORTANT:Be sure to inspect PCM and engine
grounds for being secure and clean.
A short to voltage in one of the sensor input circuits may
cause one or more of the following DTCs to be set:

P0108

P0113

P0118

P0123

P0560

P0712

P0406
IMPORTANT:If a sensor input circuit has been shorted
to voltage, ensure that the sensor is not damaged. A
damaged sensor will continue to indicate a high or low
voltage after the affected circuit has been repaired. If the
sensor has been damaged, replace it.
An open in the sensor ground circuit between the PCM
and the splice will cause one or more of the following
DTCs to be set:

P0108

P0113

P0118

P0123

P0712

P0406
A short to ground in the 5-volt reference A or B circuit will
cause one or more of the following DTCs to be set:

P0107

P0122
In the 5-volt reference circuit A, between the PCM and the
splice, will cause one or more of the following DTCs to be
set:

P0122
In the 5-volt reference circuit B, between the PCM and the
splice, will cause one or more of the following DTCs to be
set:

P0107
Check for the following conditions: