1998 ISUZU TROOPER fuse chart

6E±259 ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P1640 Driver-1-Input High Voltage
Circuit Description
Output driver modules (ODMs) are used by the
powertrain control module (PCM) to turn ªONº many of
the current-driven devices that are needed to control
various engine and transmission functions. Each ODM is
capable of controlling up to 7 separate outputs by
applying ground to the device which the PCM is
commanding ªON.º
Unlike the Quad Driver Modules (QDMs) used in prior
model years, ODMs have the capability of diagnosing
each output circuit individually. DTC P1640 set indicates
an improper voltage level has been detected on an ODM
output.
Since A/C is an option, No A/C will cause the air
conditioning clutch relay output to always fault. If a fault is
seen on the air conditioning clutch relay output, it will not
be logged as a fault until the A/C request input interrupts a
high voltage, indicating that A/C has been installed.
Conditions for Setting the DTC

Ignition ªON.º

Engine running.

No DTC 1618.

Ignition voltage is above 13.2 volts for 4 seconds.

Output voltage does not equal ignition voltage when
output is ªOFFº or output voltage is not less than 1 volt
when output is ªON.º

Above conditions occur for at least 1 second.
Action Taken When the DTC Sets

The PCM will not illuminate the malfunction indicator
lamp (MIL).

The PCM will store conditions which were present
when the DTC was set as Failure Records only. This
information will not be stored as Freeze Frame data.
Conditions for Clearing the MIL/DTC

DTC P1640 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:

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

Damaged harness ± Inspect the wiring harness for
damage, If the harness appears to be OK, disconnect
the PCM, turn the ignition ªONº and observe a
voltmeter connected to the suspect driver circuit at the
PCM harness connector while moving connectors and
wiring harnesses relates to the MIL. A change in
voltage will indicate the location of the fault.

Poor connection at component ± Examine for
damaged connectors, unplugged connector, or
damaged terminals at the following locations:
Instrument cluster harness, canister purge solenoid,
A/C clutch relay. An open ignition feed circuit at any of
these components will cause DTC P1640 to be set.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
The following PCM pins are controlled by output driver
modules (ODMs):

A13 ± ªCheck Engine Lampº

A14 ± SVS (ºCheck Transº)

B14 ± A/C Clutch
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
6. The Tech 2 Driver Module Status indicates the PCM
pin that is affected.
11. The Tech 2 may indicate ªshort circuitº even when
the problem is an open circuit. The cause of an
open circuit may be in the component itself-lamp,
purge, solenoid, or A/C compressor relay.
13.A short to ground on the ignition side of the
component will blow the fuse. Since the fuse was
checked in Step 4, a short to ground would be
between the affected component and the PCM.

6E±350
ENGINE DRIVEABILITY AND EMISSIONS
to the intake manifold through an orifice with a PCM
controlled pintle. During operation, the PCM controls
pintle position by monitoring the pintle position feedback
signal. The feedback signal can be monitored with Tech 2
as ªActual EGR Pos.º ªActual EGR Pos.º should always
be near the commanded EGR position (ºDesired EGR
Pos.º). If a problem with the EGR system will not allow the
PCM to control the pintle position properly, DTC P1406
will set. The PCM also tests for EGR flow. If incorrect flow
is detected, DTC P0401 will set. If DTCs P0401 and/or
P1406 are set, refer to the DTC charts.
The linear EGR valve is usually activated under the
following conditions:

Warm engine operation.

Above-idle speed.
Too much EGR flow at idle, cruise or cold operation may
cause any of the following conditions to occur:

Engine stalls after a cold start.

Engine stalls at idle after deceleration.

Vehicle surges during cruise.

Rough idle.
Too little or no EGR flow may allow combustion
temperatures to get too high. This could cause:

Spark knock (detonation).

Engine overheating.

Emission test failure.

DTC P0401 (EGR flow test).

Poor fuel economy.
0017
EGR Pintle Position Sensor
The PCM monitors the EGR valve pintle position input to
endure that the valve responds properly to commands
from the PCM and to detect a fault if the pintle position
sensor and control circuits are open or shorted. If the
PCM detects a pintle position signal voltage outside the
normal range of the pintle position sensor, or a signal
voltage that is not within a tolerance considered
acceptable for proper EGR system operation, the PCM
will set DTC P1406.
General Description (Positive
Crankcase Ventilation (PCV) System)
Crankcase Ventilation System Purpose
The crankcase ventilation system is use to consume
crankcase vapors in the combustion process instead of
venting them to the atmosphere. Fresh air from the
throttle body is supplied to the crankcase and mixed with
blow-by gases. This mixture is then passed through the
positive crankcase ventilation (PCV) valve into the
common chamber.
Crankcase Ventilation System Operation
The primary control is through the positive crankcase
ventilation (PCV) valve. The PCV valve meters the flow at
a rate that depends on the intake vacuum. The PCV valve
restricts the flow when the inlet vacuum is highest. In
addition, the PCV valve can seal the common chamber
off in case of sudden high pressure in the crankcase.
028RV002
While the engine is running, exhaust fuses and small
amounts of the fuel/air mixture escape past the piston

6E±44
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
No Malfunction Indicator Lamp (MIL)
060RW136
Circuit Description
The ªCheck Engineº lamp (MIL) should always be
illuminated and steady with the ignition ªONº and the
engine stopped. Ignition feed voltage is supplied to the
MIL bulb through the meter fuse. The Engine Control
Module ECM turns the MIL ªONº by grounding the MIL
driver circuit.
Diagnostic Aids
An intermittent MIL may be cause by a poor connection,
rubbed-through wire insulation, or a wire broken inside
the insulation. Check for the following items:

Inspect the ECM harness and connections for
improper mating, broken locks, improperly formed or
damaged terminals, poor terminal-to-wire
connection, and damaged harness.

If the engine runs OK, check for a faulty light bulb, an
open in the MIL driver circuit, or an open in the
instrument cluster ignition feed.
If the engine cranks but will not run, check for an open
ECM ignition or battery feed, or a poor ECM to engine
ground.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. A ªNo MILº condition accompanied by a no-start
condition suggests a faulty ECM ignition feed or
battery feed circuit.
9. Using a test light connected to B+, probe each of the
ECM ground terminals to ensure that a good ground
is present. Refer to
ECM Terminal End View for
terminal locations of the ECM ground circuits.
12.In this step, temporarily substitute a known good
relay for the ECM relay. The horn relay is nearby,
and it can be verified as ªgoodº simply by honking
the horn. Replace the horn relay after completing
this step.

6E±49 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run
Circuit Description
In this type of injector system, the Engine Control Module
(ECM) triggers the correct driver inside the injector, which
then triggers the correct injector based on the 57X signal
received from the crankshaft position sensor (CKP).
During crank, the ECM monitors the CKP 57X signal. The
CKP signal is used to determine which cylinder will fire
first. After the CKP 57X signal has been processed by the
ECM, it will command all four injectors to allow a priming
shot of fuel for all the cylinders. After the priming, the
injectors are left ªOFFº during the next four 57X reference
pulses from the CKP. This allows each cylinder a chance
to use the fuel from the priming shot. During this waiting
period, a camshaft position (CMP) signal pulse will have
been received by the ECM. The CMP signal allows the
ECM to operate the injectors sequentially based on
camshaft position. If the camshaft position signal is not
present at start-up, the ECM will begin sequential fuel
delivery with a 1-in-4 chance that fuel delivery is correct.
The engine will run without a CMP signal, but will set a
DTC code.
Diagnostic Aids
An intermittent problem may be caused by a poor
connection, rubbed-through wire insulation or a wirebroken inside the insulation. Check for the following
items:

Poor connection or damaged harness ± Inspect the
ECM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wore connection, and
damaged harness.

Faulty engine coolant temperature sensor ± Using a
Tech 2, compare engine coolant temperature with
manifold air temperature on a completely cool engine.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
4. An obvious cause of low fuel pressure would be an
empty fuel tank.
5. The engine will easily start and run if a few injectors
are disabled. It is not necessary to test all injectors
at this time since this step is only a test to verify that
all of the injectors have not been disabled by fuel
contamination.
8.If there is an open or shorted driver circuit, DTCs
0201-0204 should be set.
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 injector fuse, the 15 A engine device
fuse, and the 15A ECM 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
4Is fuel tank empty?
Ð
Fill the fuel
tank
Go to Step 5
5Is the right fuel using?
ÐGo to Step 6
Replace the
fuel
6Is the right engine oil using?
ÐGo to Step 7
Replace the
engine oil
7Using the Tech±2.
Is DTC P0192 or P0193 set? (Check rail pressure
system)
Ð
Go to DTC
P0192 or
DTC P0193
Go to Step 8
8Using the Tech±2.
Is DTC P0201 ± P0204 set? (Check inject circuit fault)
Ð
Go to DTC
P0201 ±
P0204
Go to Step 9
9Using the Tech±2.
Is DTC P1657 set? (Check ECM Main relay)
Ð
Go to DTC
P1657
Go to Step 10

6E±93 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description
The rail pressure control valve (RPCV) is built in the high
pressure oil circuit.
RPCV is an important device which is used to control oil
pressure in the HEUI system.
The circuit receives current through Engine 15A fuse from
the battery, current flowing in the order of RPCV.
Action Taken When the DTC Sets

The ECM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC

DTC P1196 can be cleared by using the Tech 2 ªClear
Infoº function or by disconnecting the ECM battery
feed.
Diagnostic Aids
Check for the following conditions:
Poor connection at ECM ± Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

Damaged harness ± Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
Rail Pressure Control display on the Tech 2 while
moving connectors and wiring harnesses related to the
Rail Pressure Control. A change in the Rail Pressure
Control display will indicate the location of the fault.
If DTC P1196 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.
If it is determined that the DTC occurs intermittently.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. Verifies that the fault is present.
DTC P1196 ± RP System High Warning

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Engine is running.
2. Observe the ªRail Pressure Controlº display on the
Tech 2.
Is the action correct?
ÐGo to Step 4Go to Step 3
3Replace the RPCV.
Is the action complete?
ÐVerify repairGo to Step 4
41. Engine is running.
2. Review and record Tech 2 Failure Records data.
3. Operate the vehicle within Failure Records
conditions as noted.
4. Using a Tech 2, monitor ª DTCº info for DTC P1196.
Does the Tech 2 indicate DTC P1196 failed this
ignition?
ÐGo to Step 5Ð
51. Check the 2 way valve.
2. Observe the ªRP Controlº display on the Tech 2.
Is the action correct?
ÐGo to Step 4Go to Step 6
6Replace the 2 way valve.
Is the action complete?
ÐVerify repairÐ

6E±127 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
DTC P0380 ± Glow Relay Circuit Open/Short

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Attempt to start the engine.
Does the engine start?
ÐGo to Step 3Go to Chart 3
31. Review and record Failure Records information.
2. Clear DTC P0380.
3. Start the engine and idle for 1 minute.
4. Observe DTCs.
Is DTC P0380 set?
ÐGo to Step 4
Refer to
Diagnostic
Aid
4Check the glow fuse 50A.
Is the glow fuse 50A damage?
ÐGo to Step 5Go to Step 6
5Replace the glow fuse 50A.
Is the action complete?
ÐVerify repairGo to Step 6
61. Ignition ªOFF.º
2. Check for an open or a short to ground in the Glow
relay circuit between the Glow relay connector and
the ECM harness connector.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 7
7Check the connections at the Glow relay and replace
the terminals if necessary.
Did any terminals require replacement?
ÐVerify repairGo to Step 8
8Replace the Glow relay.
Is the action complete?
ÐVerify repairGo to Step 9
9Check the connections at the ECM and replace the
terminals if necessary.
Did any terminals require replacement?
ÐVerify repair Go to Step 10
10Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ

6E±153 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
10. To avoid backprobing the VSS and possibly
damaging a seal or terminal, the VSS output can be
tested at the point where the transmission harness
connected to the engine harness. The green 16-way
connector is adjacent to a blue 16-way connector,
and it can be easily accessed by removing the air
cleaner assembly. The green 16-way connector is
separated, and battery voltage is applied to the VSS
through the yellow wire at one corner of the
connector. The VSS output can be monitored with a
DVM connected to the blue wire with a black tracer.
The two wires are next to each other in the 16-way
connector . The test connections are made on the
transmission side of the connector, the side that is
not clipped to the body sheetmetal.11. The speedometer-to-ECM VSS signal wire is
spliced to a wire leading to the cruise control
module. If a short to ground or voltage is found
between the ECM and speedometer, it could be
located between the splice and the cruise control
module.
DTC P0502 ±VSS No Signal

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
2Does the speedometer work?ÐGo to Step 10Go to Step 3
31. Disconnect the VSS connector.
2. Ignition ªON.º
3. Using a test light to battery +, probe the connector
ground wire.
Did the light illuminate?
ÐGo to Step 5Go to Step 4
4Repair the sensor ground.
Is the action complete?
ÐVerify repairÐ
51. Ignition ªON,º sensor disconnected.
2. Using a DVM, measure at the VSS connector
between ground and voltage supply.
Was the measurement near the specified value?
Battery
voltage
Go to Step 7Go to Step 6
6Repair the open or short to ground which may have
blown the meter fuse.
Is the action complete?
ÐVerify repairÐ
71. Ignition ªON,º VSS disconnected.
2. Using a DVM, measure at the VSS connector
between ground and the blue/black wire from the
speedometer.
Was the measurement near the specified value?
7.5-8 VGo to Step 9Go to Step 8
8Check for an open or short circuit between the
speedometer and the VSS.
Was an open or short circuit located?
ÐVerify repairGo to Step 9
9Replace the VSS.
Is the action complete?
ÐVerify repairGo to Step 10
10Replace the speedometer.
Is the action complete?
ÐVerify repairGo to Step 11

7A1±30
TRANSMISSION CONTROL SYSTEM (4L30±E)
DTC P0705 Transmission Range Switch (Mode Switch) Illegal Position
D07RW031
Circuit Description

The range switch supplies the Powertrain Control
Module (PCM) with information regarding the selector
lever position: P, R, N, D 3, 2 or L. The selector lever
position is indicated by the state of four ON/OFF
contracts. The range switch is located on one side of
the transmission. It is on the transmission manual
shaft and is fixed to the main case.

The range switch is also used to provide the
information P or N to the engine crank wiring. The
engine can be cranked only if connector M±25
terminal 4(H) is connected to terminal 1(E) which is
connected to ground.

The range switch is also used to provide the backup
lamp power in reverse. This is why the range switch is
supplied through a 10A fuse (C±3). This fuse can
burn due to a short circuit in the backup lamp.
This DTC detects when a fuse is open or the range switch
circuit does not work. This is a type ªDº DTC.
Conditions For Setting The DTC

Range switch illegal positions met for 5 seconds.
Action Taken When The DTC Sets

Default to D position.

Inhibit torque management.

Maximum line pressure.
The PCM will not illuminate the CHECK TRANS
Lamp.
Conditions For Clearing The DTC

The DTC can be cleared from the PCM history by
using a scan tool.

The DTC will be cleared from history when the vehicle
has achieved 40 warmup cycles without a failure
reported.

The PCM will cancel the DTC default actions when
the fault no longer exists and the ignition is cycled ªoffº
long enough to power down the PCM.
Diagnostic Aids

Refer to accompanying chart for the normal range
signals and the illegal combinations.

Inspect the wiring for poor electrical connections at
the PCM and at the transmission 8±way connector.
Look for possible bent, backed out, deformed or
damaged terminals. Check for weak terminal tension
as well. Also check for a chafed wire that could short
to bare metal or other wiring. Inspect for a broken wire
inside the insulation.

When diagnosing for a possible intermittent short or
open condition, move the wiring harness while
observing test equipment for a change.