2007 ISUZU KB P190 Electrical

ENGINE DRIVEABILITY AND EMISSIONS 6E–255
12 Check spark plugs for proper heat range.Were incorrect spark plugs installed? — Verify repair Go to Step 13
13 1. Remove excessive carbon buildup with a top engine cleaner.
2. Re-evaluate vehicle performance.
Is detonation still present? — Verify repair Go to Step 14
14 Check for an engine mechanical problem. Perform a cylinder compression check. Refer to Engine
Mechanical .
Was a problem found? — Verify repair Go to Step 15
15 1. Review all diagnostic procedures within this table. 2. If all procedures have been completed and nomalfunctions have been found, review/inspect the
following:
• Visual/physical inspection
• Tech 2 data
• All electrical connections within a suspected circuit and/or system
Was a problem found? — Verify repair Go to Step 16
16 Is the ECM programmed with the latest software release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved? — Verify repair Go to Step 17
17 Replace the ECM. Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure. — Verify Repair —
Step
Action Value(s) Yes No

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ENGINE DRIVEABILITY AND EMISSIONS 6E–257
14 Monitor “B1S1 (Bank 1 Sensor 1) Status ” on the Tech
2.
Is the “ B1S1 (Bank 1 Sensor 1) Status ” in the rich
condition? — Verify repair Go to Step 15
15 Check items that can cause the engine to run rich. Refer to DTC P1167 “Fuel Supply System Rich During
Deceleration Fuel Cut Off”.
Was a problem found? — Verify repair Go to Step 16
16 1. Remove the spark plugs and check for gas or oil fouling cracks, wear, improper gap, burned
electrodes, heavy deposits, or improper heat
range.
2. If spark plugs are fouled, the cause of fouling must be determined before replacing the spark plugs.
Was a problem found? — Verify repair Go to Step 17
17 Check for proper calibration of the speedometer. Does the speed indicated on the speed meter closely
match the vehicle speed displayed on the Tech 2? — Go to Step 19Go to Step 18
18 Diagnose and repair the inaccurate speedometer condition as necessary. Refer to Vehicle Speed
Sensor in Electrical Diagnosis . — Verify Repair —
19 Check for proper calibration of the fuel gauge. Was a problem found? — Verify repair Go to Step 20
20 Check for the following engine mechanical problems (refer to Engine Mechanical ):
• Low compression
• Worn camshaft
• Sticking or leaking valves
• Valve timing
Was a problem found? — Verify repair Go to Step 21
21 1. Review all diagnostic procedures within this table. 2. If all procedures have been completed and nomalfunctions have been found, review/inspect the
following:
• Visual/physical inspection
• Tech 2 data
• All electrical connections within a suspected circuit and/or system
Was a problem found? — Verify repair Go to Step 22
22 Is the ECM programmed with the latest software release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved? — Verify repair Go to Step 23
23 Replace the ECM. Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure. — Verify Repair —
Step
Action Value(s) Yes No

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ENGINE DRIVEABILITY AND EMISSIONS 6E–259
16 1. Remove excessive carbon buildup with a topengine cleaner. Refer to the instructions on the top
engine cleaner can.
2. Perform the exhaust emission test.
Does the vehicle pass the test? — System OK Go to Step 18
17 Perform the exhaust emission test. Does the vehicle pass the test? — System OK Go to Step 18
18 Run Engine. Check the fuel control Heated Oxygen Sensor
(HO2S). When monitored on the Tech 2, the HO2S
should respond quickly to different throttle positions. If
it doesn’t check for silicon or other contaminates from
fuel or use of improper sealant. The sensors may
have a white powdery coating. Silicon contamination
sends a rich exhaust signal which causes the ECM to
command and excessively lean air/fuel mixture.
Was a problem found? — Verify repair Go to Step 19
19 Monitor “ B1S1 (Bank 1 Sensor 1) Status ” on the Tech
2.
Is the “ B1S1 (Bank 1 Sensor 1) Status ” in the rich
condition? — Go to Step 20Go to Step 21
20 1. Check items that can cause the engine to run rich. Refer to Diagnostic Aids in DTC P1167 “Fuel
Supply System Rich During Deceleration Fuel Cut
Off” . Make any necessary repairs.
2. Perform the exhaust emission test.
Does the vehicle pass the test? — System OK Go to Step 22
21 1. Check items that can cause the engine to run lean. Refer to Diagnostic Aids in DTC P1171 “Fuel
Supply System Lean During Power Enrichment” .
Make any necessary repairs.
2. Perform the exhaust emission test.
Does the vehicle pass the test? — System OK Go to Step 22
22 Check for the following engine mechanical problems (refer to Engine Mechanical ):
• Low compression
• Leaking cylinder head gaskets
• Worn camshaft
• Sticking or leaking valves
• Valve timing
• Broken valve springs
Was a problem found? — Verify repair Go to Step 23
23 1. Review all diagnostic procedures within this table. 2. If all procedures have been completed and nomalfunctions have been found, review/inspect the
following:
• Visual/physical inspection
• Tech 2 data
• All electrical connections within a suspected circuit and/or system
Was a problem found? — Verify repair Go to Step 24
Step
Action Value(s) Yes No

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ENGINE DRIVEABILITY AND EMISSIONS 6E–261
DIESELING, RUN-ON SYMPTOM
DEFINITIONS: Engine continues to run after key is turned OFF, but runs very rough. If engine runs smoothly, check
the ignition switch and adjustment.
Step Action Value(s) Yes No
1 Was the “ On-Board Diagnostic (OBD) System Check ”
performed? — Go to Step 2Go 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 4Go to
Visual /
physical Check .
4 Check for a short between battery voltage and the ignition feed circuit.
Was a problem found? — Verify repair Go to Step 5
5 Check the fuel leaking from injector. Refer to Fuel System Diagnostic.
Was the problem found? — Verify repair Go to Step 6
6 1. Review all diagnostic procedures within this table. 2. If all procedures have been completed and nomalfunctions have been found, review/inspect the
following:
• Visual/physical inspection
• Tech 2 data
• All electrical connections within a suspected circuit and/or system
Was a problem found? — Verify repair Go to Step 7
7 Is the ECM programmed with the latest software release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved? — Verify repair Go to Step 8
8 Replace the ECM. Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure. — Verify repair —

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ENGINE DRIVEABILITY AND EMISSIONS 6E–263
10 Check for the following engine mechanical problems(refer to Engine Mechanical ):
• Low compression
• Leaking cylinder head gaskets
• Worn camshaft
• Sticking or leaking valves
• Valve timing
• Broken valve springs
• Camshaft drive belt slipped or stripped
Was a problem found? — Verify repair Go to Step 11
11 Check leakage at exhaust system. Check the intake and exhaust manifold for casting
flash. Refer to Engine Mechanical .
Was a problem found? — Verify repair Go to Step 12
12 1. Review all diagnostic procedures within this table. 2. If all procedures have been completed and nomalfunctions have been found, review/inspect the
following:
• Visual/physical inspection
• Tech 2 data
• All electrical connections within a suspected circuit and/or system
Was a problem found? — Verify repair Go to Step 13
13 Is the ECM programmed with the latest software release?
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”.
Was the problem solved? — Verify repair Go to Step 14
14 Replace the ECM. Is the action complete?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobilizer system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobilizer System-ECM replacement” for
the ECM/Immobilizer linking procedure. — Verify repair —
Step
Action Value(s) Yes No

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6E–278 ENGINE DRIVEABILITY AND EMISSIONS
5. Measure the CO concentration for 1-3 minutes, afteridlling the engine to allow the CO concentration to
stabilize.
6. Check the CO concentration.
7. If the value is not within specification, adjust the CO concentration. Adjustment Procedure
1. Warm-up the engine.
2. Turn OFF switches of all electrical equipment.
3. Open the CO adjuster cap.
4. Turn the CO adjuster screw checking the CO concentration
.
5. Adjust the CO concentration within specification.
Specification:
CO concentration : 0.6 －1.0 %
NOTE: Apply the liquid gasket to the CO adjuster screw
after the adjustment.

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ISUZU KB P190 2007

Engine Mechanical – V6 Page 6A1–38

2.15 Engine Compression Test
A compression pressure test of the engine cylinders determines the condition of the rings, the valves and the head
gasket.
Preliminary Steps
1 Ensure the battery is fully charged.
2 Remove the spark plugs from all cylinders, refer to 6C1-3 Engine Management – V6 – Service Operations.
NOTE
DTCs will set when the fuel system or the ignition
system is disabled and the engine is cranked.
Disregard DTCs that set under this condition.
3 Disable the fuel system by removing the fuel pump relay, refer to 8A Electrical Body & Chassis.
4 Start the engine to use any residual fuel from the fuel lines.
4 Disable the ignition coils by removing fuses 34 and 35, refer to 8A Electrical Body & Chassis .
5 Using Tech 2, command the throttle plate to wide open throttle.
Engine Cylinder Compression Test
1 Install the compression tester to cylinder number 1.
2 W hile observing the compression tester reading, turn the ignition to the START position for several seconds and then allow the ignition to return to the ON position.
3 Record the highest compression reading obtained.
4 Repeat the engine compression test for each cylinder.
Test Result Evaluation
Normal engine compression pressure builds quickly and evenly to over 965 kPa. In addition, the lowest reading of an
engine cylinder should not be less than 70 percent of the highest reading. If any cylinder fails the compression test,
adding 15 ml of engine oil to the suspected cylinder may help isolate the following fault condition.
1 A fault condition in the piston rings will produce the following result:
• A low compression on the first engine cycle
• The compression tends to build-up with the succeeding engine rotation.
• The compression improves with the addition of engine oil.
2 A fault condition in an intake or exhaust valve will produce the following result:
• A low compression on the first engine cycle
• The compression does not build with the succeeding engine rotation.
• The compression does not improve with the addition of engine oil.
3 A fault condition in the cylinder head gasket will produce the following result:
• A low compression on the first engine cycle
• The compression does not build with the succeeding engine rotation.
• The compression does not improve with the addition of engine oil.
• The suspected cylinders are positioned adjacent to each other.
• The engine oil may be contaminated with engine coolant.
• The engine coolant may be contaminated with engine oil.
Once the fault has been identified, refer to the relevant service procedure and reinstall the removed components.
Using Tech 2, clear DTCs.

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Engine Mechanical – V6 Page 6A1–161

Reinstall
1 Fill the stationary hydraulic lash adjuster (SHLA) with
clean engine oil. Take precautions to prevent
scratching the pivot sphere area of the SHLA.
2 Lubricate the SHLA bores in the cylinder head with clean engine oil.
3 Install the SHLA in the cylinder head (2).
4 Apply a liberal amount of commercially available camshaft/lifter prelube to the SHLA pivot spheres.
5 Install the rocker arms, refer to 3.20 Rocker Arm.


CAUTION
Ensure each lash adjuster (1) is filled with
clean engine oil and the adjuster does not
tip over, plunger down, before the
installation. The loss of oil in the adjuster
lower pressure chamber, or the dry
stroking/cycling of the adjuster plunger, will
allow air to enter the high pressure chamber
of the valve lifter. Air in the high pressure
chamber of the adjuster may not be purged
causing cavitation and extensive engine
component damage.
Figure 6A1 – 274

3.22 Cylinder Head Assembly
Remove
Right-hand Side (Bank 1) Cylinder Head
1 Remove the heater hoses and heater pipe assembly, refer to 6B1 Engine Cooling – V6.
2 Remove the intake manifold assembly, refer to 3.10 Intake Manifold Assembly – Complete.
3 Remove the exhaust manifold, refer to 3.11 Exhaust Manifold Assembly.
4 Remove engine harness ground terminal attaching bolts from the cylinder head, refer to 8A Electrical Body and Chassis.
5 Remove the right-hand side secondary timing chain, refer to 3.16 Timing Chains, Tensioners, Shoes and Guides.
6 Remove the camshaft sprockets, refer to 3.18 Camshaft Sprocket.
7 Remove the cylinder head attaching bolt (1), eight places.
8 Remove the cylinder head.

NOTE
There is no bolt fitted to the hole in the rear of
the right-hand-hand cylinder head.
Figure 6A1 – 275

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