Isuzu Trooper (1998-2002 year). Service manual — part 632
6E–176
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Symptom Diagnosis
Preliminary Checks
Before using this section, perform the “On–Board
Diagnostic (OBD) System Check” and verify all of the
following items:
D
The powertrain control module (ECM) and
malfunction indicator lamp (MIL) (CHECK ENGINE
lamp) are operating correctly.
D
There are no DTC(s) stored.
D
Tech–2 data is within normal operating range. Refer
to
Typical Scan Data Values.
D
Verify the customer complaint and locate the correct
symptom in the table of contents. Perform the
procedure included in the symptom chart.
Visual/Physical Check
Several of the symptom procedures call for a careful
visual/physical check. This can lead to correcting a
problem without further checks and can save valuable
time.
This check should include the following items:
D
ECM grounds for cleanliness, tightness and proper
location.
D
Vacuum hoses for splits, kinks, and proper
connections, as shown on the “Vehicle Emission
Control Information” label. Check thoroughly for any
type of leak or restriction.
D
Air intake ducts for collapsed or damaged areas.
D
Injector wires for cracking, hardness, and carbon
tracking.
D
Wiring for proper connections, pinches and cuts.
Intermittents
IMPORTANT:
An intermittent problem may or may not
turn on the malfunction indicator lamp (MIL) or store a
DTC. DO NOT use the Diagnostic Trouble Code (DTC)
charts for intermittent problems. The fault must be
present to locate the problem.
Most intermittent problems are caused by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions:
D
Poor mating of the connector halves or a terminal not
fully seated in the connector (backed out).
D
Improperly formed or damaged terminal.
D
All connector terminals in the problem circuit should
be carefully checked for proper contact tension.
D
Poor terminal–to–wire connection. This requires
removing the terminal from the connector body to
check.
Road test the vehicle with a Digital Multimeter
(5-8840-0285-0) connected to a suspected circuit. An
abnormal voltage when the malfunction occurs is a good
indication that there is a fault in the circuit being
monitored.
Use a scan tool to help detect intermittent conditions. The
scan tools have several features that can be used to
locate an intermittent condition. Use the following feature
to find intermittent faults:
D
Using a Tech–2 “Freeze Frame” buffer or “Failure
Records” buffer can aid in locating an intermittent
condition. Review and record the information in the
freeze frame or failure record associated with the
intermittent DTC being diagnosed. The vehicle can
be driven within the conditions that were present
when the DTC originally set.
To check for loss of diagnostic code memory, disconnect
the MAP sensor and idle the engine until the MIL (CHECK
ENGINE lamp) comes on. DTC P0107 should be stored
and kept in memory when the ignition is turned “OFF.” If
not, the ECM is faulty. When this test is completed, make
sure that you clear the DTC P0107 from memory.
An intermittent MIL (CHECK ENGINE lamp) with no
stored DTC may be caused by the following:
D
MIL (CHECK ENGINE lamp) wire to ECM shorted to
ground.
D
Poor ECM grounds. Refer to the ECM wiring
diagrams.
Check for improper installation of electrical options such
as lights, cellular phones, etc.
Check for an open diode across the A/C compressor
clutch and check for other open diodes (refer to wiring
diagrams in
Electrical Diagnosis).
If problem has not been found, refer to
ECM Connector
Symptom tables.
6E–177
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Hard Start Symptom
Step
Action
Value(s)
Yes
No
1
DEFINITION:
Engine cranks, but does not start for a long time. Does
eventually run, or may start but immediately stalls.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—
Go to
Step 2
Go to
OBD
System
Check
2
1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—
Verify repair
Go to
Step 3
3
Was a visual/physical check performed?
—
Go to
Step 4
Go to
Visual/Physic
al Check
4
Check engine coolant temperature (ECT) sensor for
shift in value. After 8 hours with the hood up and the
engine not running, connect the scan tool. With the
ignition “ON” and the engine not running, compare
engine coolant temperature to manifold air
temperature.
Are ECT and MAT within the specified value of each
other?
±
5
°
C (
±
9
°
F)
Go to
Step 8
Go to
Step 5
5
1. Using Tech–2, display the engine coolant
temperature and note the value.
2. Check the resistance of the engine coolant
temperature sensor.
3. Refer to
Engine Coolant Temperature Sensor
Temperature vs. Resistance chart on DTC P0118
Diagnostic Support for resistance specifications.
Is the resistance value near the resistance for the
temperature noted?
—
Go to
Step 7
Go to
Step 6
6
Replace the ECT sensor.
Is the action complete?
—
Verify repair
—
7
Locate and repair high resistance or poor connection in
the ECT signal circuit or the ECT sensor ground.
Is the action complete?
—
Verify repair
—
8
1. Injector Test
Operate the each injector by Tech 2 with the
ignition “ON” and check if the working noise
confirm.
2. If a problem is found, check the harness or replace
the injector.
Is the action complete?
—
Verify repair
Go to
Step 9
9
Check the oil rail pressure by Tech 2 at the cranking.
Is the pressure near the specified value?
Less than 3
MPa
Go to
Step 10
Go to
Step 11
10
Check the oil leakage on the high oil pressure line.
If the oil leakage is found, repair as necessary.
Was the oil leakage found?
—
Verify repair
Go to
Step 11
11
1. Check for water-or alcohol-contaminated fuel.
2. If a problem is found, repair as necessary.
Was a problem found?
—
Verify repair
Go to
Step 12
6E–178
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Hard Start Symptom
(Cont'd)
Step
No
Yes
Value(s)
Action
12
1. Check the battery voltage.
2. If a problem is found, repair as necessary.
Was a problem found?
—
Verify repair
Go to
Step 13
13
1. Check for the following engine mechanical
problems (Refer to
Engine Mechanical):
D
Low compression
D
Leaking cylinder head gaskets
D
Worn or incorrect camshaft
D
Camshaft drive belt slipped or stripped
2. If a problem is found, repair as necessary.
Was a problem found?
—
Verify repair
Go to
Step 14
14
1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:
D
Visual/physical inspection
D
Tech–2 data
D
Freeze Frame data/Failure Records buffer
D
All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—
Verify repair
Contact
Technical
Assistance
6E–179
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Surges and/or Chuggles Symptom
Step
Action
Value(s)
Yes
No
1
DEFINITION:
Engine power variation under steady throttle or cruise.
Feels like the vehicle speeds up and slows down with
no change in the accelerator pedal.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—
Go to
Step 2
Go to
OBD
System
Check
2
1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—
Verify repair
Go to
Step 3
3
Was a visual/physical check performed?
—
Go to
Step 4
Go to
Visual/
Physical
Check
4
Be sure that the driver understands transmission
torque converter clutch and A/C compressor operation
as explained in the owner’s manual.
Inform the customer how the TCC and the A/C clutch
operate.
Is the customer experiencing a normal condition?
—
System OK
Go to
Step 5
5
1. Check the priming pump. Refer to
Fuel System.
2. If a problem is found, operate the priming pump.
Was a problem found?
—
Verify repair
Go to
Step 6
6
1. Injector Test
Operate the each injector by Tech 2 with the
ignition “ON” and check if the working noise
confirm.
2. If a problem is found, check the harness and repair
as necessary.
Is the action complete?
—
Verify repair
Go to
Step 7
7
1. Check ECM grounds for the cleanliness, tightness
and proper locations. Refer to the ECM wiring
diagrams in
Electrical Diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
—
Verify repair
Go to
Step 8
8
1. Check AP sensor connections.
2. If a problem is found, replace the faulty terminals as
necessary. Refer to
Electrical Diagnosis for wiring
repair procedures.
Was a problem found?
—
Verify repair
Go to
Step 9
9
1. Visually/physically check vacuum hoses for splits,
kinks, and proper connections and routing as
shown on the “Vehicle Emission Control
Information” label.
2. If a problem is found, repair as necessary.
Was a problem found?
—
Verify repair
Go to
Step 10
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст