1998 ISUZU TROOPER drive shaft connection

6E±264
ENGINE DRIVEABILITY AND EMISSIONS
Hard Start Symptom

 
StepNo Ye s Value(s) Action
121. Remove spark plugs. Check for wet plugs, cracks,
wear, improper gap, burned electrodes, or heavy
deposits. Refer to
Electronic Ignition System.
NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 13
131. Check for a loose ignition coil ground.
Refer to
Electronic Ignition System.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 14
141. Remove the ignition coils and check the ignition
coils for cracks or carbon tracking.
2. If a problem is found, replace affected coil(s) as
necessary.
Was a problem found?
ÐVerify repairGo to Step 15
151. Check IAC operation. Perform the procedure in the
DTC P0506, Step 6 diagnostic table.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 16
161. Check for the following engine mechanical
problems (refer to
Engine Mechanical):

Low compression

Leaking cylinder head gaskets

Worn or incorrect camshaft

Camshaft drive belt slipped or stripped
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 17
171. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records buffer

All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Contact
Technical
Assistance

6E±269 ENGINE DRIVEABILITY AND EMISSIONS
Lack of Power, Sluggish or Spongy Symptom

 
StepNo Ye s Value(s) Action
111. Check the PCM grounds for the cleanliness,
tightness and proper locations. Refer to the PCM
wiring diagrams in
Electrical Diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 12
121. Check the exhaust system for possible restriction:

Inspect the exhaust system for damaged or
collapsed pipes.

Inspect the muffler for heat distress or possible
internal failure.

Check for a possible plugged three-way
catalytic converter by checking the exhaust
system back pressure. Refer to
Restricted
Exhaust System Check
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 13
131. Check the torque converter clutch (TCC) for proper
operation. Refer to
4L30-E Transmission
Diagnosis
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 14
141. Check for an engine mechanical problem. Check
for low compression, incorrect or worn camshaft,
loose timing belt, etc. Refer to
Engine Mechanical.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 15
151. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records buffer

All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Contact
Technical
Assistance

6E±274
ENGINE DRIVEABILITY AND EMISSIONS
Rough, Unstable, or Incorrect Idle, Stalling Symptom

 
StepNo Ye s Value(s) Action
171. Check ignition coils for cracks or carbon tracking.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 18
18Using Tech 2, monitor the throttle position (TP) angle
with the engine idling.
Is the TP angle at the specified value and steady?
0%Go to Step 19
Refer to DTC
P0123
for
further
diagnosis
191. Check the positive crankcase ventilation (PCV)
valve for proper operation. Refer to
Crankcase
Ventilation System
.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 20
201. Check the transmission range switch circuit. Use
Tech 2 and be sure Tech 2 indicates that the vehicle
is in drive with the gear selector in drive or overdrive.
2. If a problem is found, diagnose and repair the
transmission range switch as necessary (refer to
4L30-E Automatic Transmission Diagnosis).
Was a problem found?
ÐVerify repairGo to Step 21
211. Check for the following engine mechanical items.
Refer to
Engine Mechanical for diagnosis
procedures:

EGR valve mounted backward. Compare with
a known-good vehicle.

Low compression

Sticking or leaking valves

Worn camshaft lobe(s)

Camshaft drive belt slipped or stripped

Incorrect valve timing

Worn rocker arms

Broken valve springs
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 22
221. Check for faulty motor mounts. Refer to Engine
Mechanical
for inspection of mounts.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 23
231. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records buffer

All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Contact
Technical
Assistance

6E±281 ENGINE DRIVEABILITY AND EMISSIONS
Backfire Symptom

 
StepNo Ye s Value(s) Action
91. Check for the following engine mechanical
conditions.
Refer to
Engine Mechanical for diagnosis
procedures:

Low compression

Sticking or leaking valves

Worn camshaft lobe(s)

Camshaft drive belt slipped or stripped

Incorrect valve timing
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 10
101. Check the intake and exhaust manifold(s) for
casting flash. Refer to
Engine Mechanical.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 11
111. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records butter

All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Contact
Technical
Assistance

6E±284
ENGINE DRIVEABILITY AND EMISSIONS
Cuts Out, Misses Symptom

 
StepNo Ye s Value(s) Action
171. Check ignition coils for cracks or carbon tracking.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 18
18Using Tech 2, monitor the TP angle with the engine
idling.
Is the TP angle at the specified value and steady?
0%Go to Step 19
Refer to DTC
P0123
for
further
diagnosis
191. Check the PCV valve for proper operation. Refer to
Crankcase Ventilation System.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 20
201. Check the transmission range switch circuit. Use
Tech 2 and be sure Tech 2 indicates that the vehicle
is in drive with the gear selector in drive or overdrive.
2. If a problem is found, diagnose and repair the
transmission range switch as necessary (refer to
4L30-E Automatic Transmission Diagnosis).
Was a problem found?
ÐVerify repairGo to Step 21
211. Check the following engine mechanical items.
Refer to
Engine Mechanical for diagnosis
procedures:

Low compression

Sticking or leaking valves

Worn camshaft lobe(s)

Camshaft drive belt slipped or stripped

Incorrect valve timing

Worn rocker arms

Broken valve springs
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 22
221. Check for faulty motor mounts. Refer to Engine
Mechanical
for inspection of mounts.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 23
231. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records butter

All electrical connections within a suspected
circuit and/or system
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Contact
Technical
Assistance

00 Ð 4 SERVICE INFORMATION
Checkpoint Possible cause Correction
Engine stop
mechanismDefective fuel cut solenoid valve Replace the fuel cut solenoid valve
3. ENGINE TURNS OVER BUT DOES NOT START
FUEL IS NOT BEING DELIVERED TO THE INJECTION PUMP
Fuel Fuel tank is empty Fill the fuel tank
Fuel piping Clogged or damaged fuel lines. Loose fuel
line connectionRepair or replace the fuel lines
Retighten the fuel line connection
Fuel filter Fuel filter overflow valve does not close Repair or replace the fuel filter
overflow valve
Clogged fuel filter element Replace the fuel filter element or
the filter cartridge
Fuel system Air in the fuel system Bleed the air from the fuel system
Fuel feed pump Defective feed pump Repair or replace the feed pump
FUEL IS BEING DELIVERED TO THE INJECTION PUMP
Fuel Use of the wrong fuel Use the correct fuel
Water particles in the fuel Carge the fuel
Fuel system Air in the injection pump Bleed the air from the fuel system
Injection nozzle Injection nozzle sticking Replace the injection nozzle
Injection nozzle injection starting pressure
too low
Improper spray conditionAdjust or replace the injection
nozzle
Injection pump Defective fuel injection nozzle resulting in
the fuel drippage after fuel injectionReplace the delivery valve
Defective injection pump control rack
operationRepair or replace the injection pump
control rack
Injection pump plunger worn or stuck Replace the injection pump plunger
assembley
Injection pump drive shaft seizure or other
damageReplace the injection drive shaft
Injection pump governor spring seizure Replace the injection pump
governor spring

6E±25 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
General Service Information
Serviceability Issues
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Accordingly, if commercially sold sensor
or switch is installed, it makes a wrong diagnosis and turn
on the MIL (ªCheck Engineº lamp).
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the MIL (ªCheck
Engineº lamp).
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the MIL
(ªCheck Engineº lamp) to turn on if the vehicle is not
maintained properly. Restricted oil filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD. Poor vehicle
maintenance can not be classified as a ªnon-vehicle
faultº, but with the sensitivity of OBD diagnostics, vehicle
maintenance schedules must be more closely followed.
Related System Faults
Many of the OBD system diagnostics will not run if the
ECM detects a fault on a related system or component.
Visual/Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:

Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.

Inspect hoses that are difficult to see behind other
components.

Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.
Serial Data Communications
Class II Serial Data Communications
This vehicle utilizes the ªClass IIº communication system.
Each bit of information can have one of two lengths: longor short. This allows vehicle wiring to be reduced by
transmitting and receiving multiple signals over a single
wire. The messages carried on Class II data streams are
also prioritized. If two messages attempt to establish
communications on the data line at the same time, only
the message with higher priority will continue. The device
with the lower priority message must wait.
On this vehicle the Tech 2 displays the actual values for
vehicle parameters. It will not be necessary to perform
any conversions from coded values to actual values.
On-Board Diagnostic (OBD)
On-Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive. When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The diagnostic test has passed during the current
ignition cycle.

The fault identified by the diagnostic test is not
currently active.
When a diagnostic test reports a fail result, the diagnostic
executive records the following data:

The diagnostic test has been completed since the last
ignition cycle.

The fault identified by the diagnostic test is currently
active.

The fault has been active during this ignition cycle.

The operating conditions at the time of the failure.
Comprehensive Component Monitor
Diagnostic Operation
Comprehensive component monitoring diagnostics are
required to operate engine properly.
Input Components:
Input components are monitored for circuit continuity and
out-of-range values. This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable. Accel
Position (AP) sensor that indicates high throttle position
at low engine loads or MAP voltage. Input components
may include, but are not limited to the following sensors:

Intake Air Temperature (IAT) Sensor

Crankshaft Position (CKP) Sensor

Intake throttle Position (ITP) Sensor

Engine Coolant Temperature (ECT) Sensor

Camshaft Position (CMP) Sensor

Manifold absolute Pressure (MAP) Sensor

Accel Position Sensor

Fuel Temp Sensor

Rail Pressure Sensor

Oil Temp Sensor

EGR Pressure Sensor

Vehicle Speed Sensor

6E±39 4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Engine Control Module ECM
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 ECM memory.
Diagnostic trouble codes can also be cleared by turning
the ignition ªOFFº and disconnecting the battery power
from the ECM for 30 seconds. Turning off the ignition and
disconnecting the battery power from the ECM will cause
all diagnostic information in the ECM memory to be
cleared. Therefore, all the diagnostic tests will have to be
re-run.
Since the ECM 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 ECM connections
or the ECM is the cause of a problem, and the ECM is
replaced, but this does not correct the problem, one of the
following may be the reason:

There is a problem with the ECM 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 components 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 ECM using internal electronic switches called
drivers. A shorted solenoid, relay coil, or harness will
not damage the ECM but will cause the solenoid or
relay to be inoperative.
Multiple ECM Information Sensor
DTCS Set
Circuit Description
The Engine Control Module ECM monitors various
sensors to determine the engine operating conditions.
The ECM controls fuel delivery, spark advance,
transmission operation, and emission control device
operation based on the sensor inputs.
The ECM provides a sensor ground to all of the sensors.
The ECM 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 fuel temperature (FT) sensor

The engine coolant temperature (ECT) sensor

The Intake air temperature (IAT) sensor
The ECM provides the following sensors with a 5-volt
reference and a sensor ground signal:

The Intake throttle position sensor

The manifold absolute pressure sensor

The rail pressure sensor

The accelerator position sensor

The oil temperature sensor
The camshaft position sensor

The crankshaft position sensor

The EGR pressure sensor
The ECM monitors the signals from these sensors in
order to determine their operating status.
Diagnostic Aids
IMPORTANT:Be sure to inspect ECM 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:

P0337

P0342

P1193

P1404

P1405

P1488
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 ECM
and the splice will cause one or more of the following
DTCs to be set:

P0337

P0342

P0117
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:

P0112

P0117

P0182

P0197
An open in the 5-volt reference circuit A, between the
ECM and the splice will cause one or more of the following
DTCs to be set:

P0107

P0405

P1194

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

P1485
Check for the following conditions:

Poor connection at ECM. Inspect the harness
connectors for backed-out terminals, improper
mating, broken locks, improperly formed or damage
terminals, and a poor terminal-to-wire connection.

Damaged harness. Inspect the wiring harness for
damage. If the harness is not damaged, observe an
affected sensor's displayed value on the Tech 2 with
the ignition ªONº and the engine ªOFFº while you
move the connectors and the wiring harnesses
related to the following sensors:

ECT Sensor