1998 ISUZU TROOPER reset

6E±28
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
in the ECM's memory, the DTC(s) will be output from the
lowest to the highest, with each DTC being displayed
three times.
The DTC display will continue as long as the DLC is
shorted.
Reading Diagnostic Trouble Codes Using
a TECH 2
The procedure for reading diagnostic trouble code(s) is to
used a diagnostic Tech 2. When reading DTC(s), follow
instructions supplied by Tech 2 manufacturer.
For the 1998 model year, Isuzu dealer service
departments will continue to use Tech 2.
Clearing Diagnostic Trouble Codes
IMPORTANT:Do not clear DTCs unless directed to do
so by the service information provided for each diagnostic
procedure. When DTCs are cleared, the Freeze Frame
and Failure Record data which may help diagnose an
intermittent fault will also be erased from memory.
If the fault that caused the DTC to be stored into memory
has been corrected, the Diagnostic Executive will begin to
count the ªwarm-upº cycles with no further faults
detected, the DTC will automatically be cleared from the
ECM memory.To clear Diagnostic Trouble Codes (DTCs), use the Tech
2 ªclear DTCsº or ªclear informationº function. When
clearing DTCs follow instructions supplied by the Tech 2
manufacturer.
When a Tech 2 is not available, DTCs can also be cleared
by disconnecting
one of the following sources for at least
thirty (30) seconds.
NOTE: To prevent system damage, the ignition key must
be ªOFFº when disconnecting or reconnecting battery
power.

The power source to the control module. Examples:
fuse, pigtail at battery ECM connectors etc.

The negative battery cable. (Disconnecting the
negative battery cable will result in the loss of other
on-board memory data, such as preset radio tuning).
060RW169

6E±41 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
EGR (Exhaust Gas Recirculation)
Diagnosis

A diagnosis of the EGR system is covered by DTC
P1403.

EGR VSV circuit diagnosis is covered by DTC P1404.

EGR pressure sensor diagnosis is covered by DTC
P405 and/or P406.

EGR EVRV circuit diagnosis is covered by DTC
P1405. Refer to the DTC charts.
Tech 2 Data Definitions and Ranges
A/C CLUTCH±Tech 2 Displays ON or OFF±
Indicates whether the A/C has commanded the A/C
clutch ON.
MAP kPa Ð Tech 2 Range 10-105 kPa/0.00-5.00
Volts Ð
The manifold absolute pressure reading is determined
from the MAP sensor signal monitored during key up and
wide open throttle (WOT) conditions. The manifold
absolute pressure is used to compensate for altitude
differences and is normally displayed around ª61-104º
depending on altitude and manifold absolute pressure.
CMP ACT. COUNTER ±Cam Position
DESIRED IDLE Ð Tech 2 Range 0-3187 RPM Ð
The idle speed that the ECM is commanding. The ECM
will compensate for various engine loads based on engine
coolant temperature, to keep the engine at the desired
speed.
ECT Ð (Engine Coolant Temperature) Tech 2
Range ±40
C to 151
C (±40
F to 304
F) Ð
The engine coolant temperature (ECT) is mounted in the
coolant stream and sends engine temperature
information to the ECM. The ECM applies 5 volts to the
ECT sensor circuit. The sensor is a thermistor which
changes internal resistance as temperature changes.
When the sensor is cold (high resistance), the ECM
monitors a high signal voltage and interprets that as a cold
engine. As the sensor warms (decreasing resistance),
the voltage signal will decrease and the ECM will interpret
the lower voltage as a warm engine.
ENGINE RUN TIME Ð Tech 2 Range
00:00:00-99:99:99 Hrs:Min:Sec Ð
Indicates the time elapsed since the engine was started.
If the engine is stopped, engine run time will be reset to
00:00:00.
ENGINE SPEED Ð Range 0-9999 RPM Ð
Engine speed is computed by the ECM from the 57X
reference input. It should remain close to desired idle
under various engine loads with engine idling.Air Intake Valve meter POSITION Ð Tech 2 Range
0-100 % Ð
IAT (INTAKE AIR TEMPERATURE)Ð Tech 2 Range
±40
C to 151
C (±40
F to 304
F) Ð
The ECM converts the resistance of the intake air
temperature sensor to degrees. Intake air temperature
(IAT) is used by the ECM to adjust fuel delivery and spark
timing according to incoming air density.
MAP Ð Tech 2 Range 10-105 kPa (0.00-4.97 Volts)Ð
The manifold absolute pressure (MAP) sensor measures
the change in the boost pressure.
MIL Ð Tech 2 Displays ON or OFF Ð
Indicates the ECM commanded state of the malfunction
indicator lamp.
AP Ð Tech 2 Range 0%-100% Ð
AP (Accelerator position) angle is computed by the ECM
from the AP sensor voltage. AP angle should display
ª0%º at idle and ª100%º at wide open throttle.
AP SENSOR Ð Tech 2 Range 0.00-5.00 Volts Ð
The voltage being monitored by the ECM on the AP
sensor signal circuit.
VEHICLE SPEEDÐTech 2 Range 0-255 km/h (0-155
mph)±
The vehicle speed sensor signal is converted into km/h
and mph for display.
Typical Scan Data Values
Use the Typical Scan Data Values Table only after the
On-Board Diagnostic System Check has been
completed, no DTC(s) were noted, and you have
determined that the on-board diagnostics are functioning
properly. Tech 2 values from a properly-running engine
may be used for comparison with the engine you are
diagnosing. The typical scan data values represent
values that would be seen on a normally-running engine.
NOTE: A Tech 2 that displays faulty data should not be
used, and the problem should be reported to the Tech 2
manufacturer. Use of a faulty Tech 2 can result in
misdiagnosis and unnecessary replacement of parts.
Only the parameters listed below are referred to in this
service manual for use in diagnosis. For further
information on using the Tech 2 to diagnose the ECM and
related sensors, refer to the applicable reference section
listed below. If all values are within the typical range
described below, refer to the
Symptoms section for
diagnosis.
Test Conditions
Engine running, lower radiator hose hot, transmission in
park or neutral, accessaries off, brake not applied and air
conditioning off.

6E±100
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0201 ± Injector # 1 Circuit Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0201 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0201 reset?
ÐGo to Step 5Ð
5Check the Injector test.
Does the working noise confirm?
ÐGo to Step 6Go to Step 7
61. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Dose DTC P0201 reset?
ÐVerify repairGo to Step 7
7Check for an open circuit between the injector
connector and the ECM.
Was there an open circuit?
ÐGo to Step 8Go to Step 9
8Repair the open circuit.
Is the action complete?
ÐVerify repairÐ
9Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairGo to Step 10
10Replace the Injector (Refer to the Injector Group Sign
Programming).
Is the action complete?
ÐVerify repairÐ

6E±102
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0202 ± Injector # 2 Circuit Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0202 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0202 reset?
ÐGo to Step 5Ð
5Check the Injector test.
Does the working noise confirm?
ÐGo to Step 6Go to Step 7
61. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Dose DTC P0202 reset?
ÐVerify repairGo to Step 7
7Check for an open circuit between the injector
connector and the ECM.
Was there an open circuit?
ÐGo to Step 8Go to Step 9
8Repair the open circuit.
Is the action complete?
ÐVerify repairÐ
9Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairGo to Step 10
10Replace the Injector (Refer to the Injector Group Sign
Programming).
Is the action complete?
ÐVerify repairÐ

6E±104
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0203 ± Injector # 3 Circuit Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0203 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0203 reset?
ÐGo to Step 5Ð
5Check the Injector test.
Does the working noise confirm?
ÐGo to Step 6Go to Step 7
61. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Dose DTC P0203 reset?
ÐVerify repairGo to Step 7
7Check for an open circuit between the injector
connector and the ECM.
Was there an open circuit?
ÐGo to Step 8Go to Step 9
8Repair the open circuit.
Is the action complete?
ÐVerify repairÐ
9Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairGo to Step 10
10Replace the Injector (Refer to the Injector Group Sign
Programming).
Is the action complete?
ÐVerify repairÐ

6E±106
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0204 ± Injector #4 Circuit Fault

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Will the engine start?
ÐGo to Step 3
Go to Engine
Cranks But
Will Not Run
chart
31. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Does DTC P0204 reset?
ÐGo to Step 5Go to Step 4
41. Review the Freeze Frame data with the ignition
ªONº and the engine ªOFFº and note the
parameters.
2. Operate the vehicle within the Freeze Frame
conditions as noted.
Does P0204 reset?
ÐGo to Step 5Ð
5Check the Injector test.
Does the working noise confirm?
ÐGo to Step 6Go to Step 7
61. Install the Tech 2. Clear the DTC.
2. Idle the engine for one minute.
Dose DTC P0204 reset?
ÐVerify repairGo to Step 7
7Check for an open circuit between the injector
connector and the ECM.
Was there an open circuit?
ÐGo to Step 8Go to Step 9
8Repair the open circuit.
Is the action complete?
ÐVerify repairÐ
9Is the action complete?ÐVerify repairGo to Step 10
10Replace the Injector (Refer to the Injector Group Sign
Programming).
Is the action complete?
ÐVerify repairÐ

8DÐ16 WIRING SYSTEM
Circuit Breaker
The circuit breaker is a protective device designed to
open the circuit when a current load is in excess of rated
breaker capacity. If there is a short or other type of
overload condition in the circuit, the excessive current will
open the circuit between the circuit breaker terminals.
The reset knob (1) pops out when the circuit is open. Push
the reset knob in place to restore the circuit after repairing
it.
Relay
Battery and load location may require that a switch be
placed some distance from either component. This
means a longer wire and a higher voltage drop (1).
The installation of a relay between the battery and the
load reduces the voltage drop (2).
Because the switch controls the relay, amperage through
the switch can be reduced.
Push
LOAD
12LOAD
RELAY
D08RW404
1

WIRING SYSTEM 8D – 411
Circuit Diagram (RHD 6V*1 W/O T.O.D)-1
%38
3
C-3910H-42
0.5
B/R0.5
B/R 0.5
B/R
B
DC
A
FENDER-RH
H-104M-10
2A
I 0.5
L/Y0.5
L/Y0.5
L/Y
1
M-109H-103H-9
0.5
LG/W0.5
LG/W
0.5
LG/W0.5
LG/W 0.5
LG/W0.5
R/W
SPEEDO-
METER
RESET
SWTACHOMETERENGINE
COOLANT
TEMPERATURE
GAUGEFUEL
GAUGEOIL
PRESSURE
GAUGE FUSE C-15
3
M-10125H-9
11H-10
VEHICLE
SPEED SENSOR
I-10
0.5
Y/B0.5
Y/B0.5
Y/B
1
E-191 4H-24
11H-6I-10
2
H-8
PCM
(D7)CRUISE CONTROL
UNIT(9)0.5
B/R
15
H-9
PCM
(C10)9I-9
0.5
Y/R
14H-2520I-10
ENGINE
COOLANT
TEMPERATURE
UNIT
0.5
Y/G0.5
Y/V0.5
Y/B
1E-217 19H-9
10H-6I-10
OIL
PRESSURE
UNIT
8
I-10METER
ODO/TRIP
METER