2007 ISUZU KB P190 low oil pressure

6E–158 ENGINE DRIVEABILITY AND EMISSIONS
12 Check for the following conditions. • Objects blocking the IAC valve.
• Objects blocking the throttle valve.
• Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found? — Verify repair Go to Step 13
13 Check for injector for the affected bank. Refer to “Injector Coil Test & Injector Balance Test
Procedure” 6E-98 page .
Was the injector operation correct? —Go to Step 14Refer to
Injector
Coil Test & Injector
Balance Test Procedure
14 Check for fuel pressure. Refer to “Fuel System Diagnosis” 6E-108 page .
Was the fuel pressure correct? — Go to Step 15Refer to
Fuel
System
Diagnosis
15 Replace the O
2 sensor.
Was the problem solved? — 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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ISUZU KB P190 2007

6E–162 ENGINE DRIVEABILITY AND EMISSIONS
10 Check for the following conditions. • Objects blocking the IAC valve.
• Objects blocking the throttle valve.
• Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found? — Verify repair Go to Step 11
11 Check for injector for the affected bank. Refer to “Injector Coil Test & Injector Balance Test
Procedure” 6E-98 page .
Was the injector operation correct? —Go to Step 12Refer to
Injector
Coil Test & Injector
Balance Test Procedure
12 Check for fuel pressure. Refer to “Fuel System Diagnosis” 6E-108 page.
Was the fuel pressure correct? — Go to Step 13Refer to
Fuel
System
Diagnosis
13 Replace the O
2 sensor.
Was the problem solved? — Verify repair Go to Step 14
14 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 15
15 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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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–213
8 1. Using the Tech 2, ignition “On” and engine “On”. 2. Select the “Miscellaneous Test” and perform the“IAC Control” in the “IAC System”.
3. Operate the Tech 2 in accordance with procedure.
Was the engine speed changed, when the IAC valve
is operating step by step? — Go to Step 10Go to Step 9
9 Check for the following conditions. • Objects blocking the IAC valve.
• Objects blocking the throttle valve.
• Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found? — Verify repair Go to Step 14
10 Check for injector for the affected bank. Refer to “Injector Coil Test & Injector Balance Test
Procedure” 6E-98 page .
Was the injector operation correct? —Go to Step 11Refer to
Injector
Coil Test & Injector
Balance Test Procedure
11 Check for fuel pressure. Refer to “Fuel System Diagnosis” 6E-108 page.
Was the fuel pressure correct? — Go to Step 15Refer to
Fuel
System
Diagnosis
12 Replace the TPS. Is the action complete? — Verify repair —
13 Replace the MAP sensor. Is the action complete? — Verify repair —
14 Replace the IAC valve. Is the action complete? — Verify repair —
15 Replace the O
2 sensor.
Was the problem solved? — 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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ISUZU KB P190 2007

6E–216 ENGINE DRIVEABILITY AND EMISSIONS
7 Remove the MAP sensor and check for the followingconditions.
• Objects blocking the air cleaner.
• Objects blocking the MAP sensor.
• Objects blocking the throttle valve.
• Vacuum leaking at intake duct.
• Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found? — Verify repair Go to Step 13
8 1. Using the Tech 2, ignition “On” and engine “On”. 2. Select the “Miscellaneous Test” and perform the“IAC Control” in the “IAC System”.
3. Operate the Tech 2 in accordance with procedure.
Was the engine speed changed, when the IAC valve
is operating step by step? — Go to Step 10Go to Step 9
9 Check for the following conditions. • Objects blocking the IAC valve.
• Objects blocking the throttle valve.
• Vacuum leaking at throttle body.
If a problem is found, repair as necessary.
Was the problem found? — Verify repair Go to Step 14
10 Check for injector for the affected bank. Refer to “Injector Coil Test & Injector Balance Test
Procedure” 6E-98 page .
Was the injector operation correct? —Go to Step 11Refer to
Injector
Coil Test & Injector
Balance Test Procedure
11 Check for fuel pressure. Refer to “Fuel System Diagnosis” 6E-108 page.
Was the fuel pressure correct? — Go to Step 15Refer to
Fuel
System
Diagnosis
12 Replace the TPS. Is the action complete? — Verify repair —
13 Replace the MAP sensor. Is the action complete? — Verify repair —
14 Replace the IAC valve. Is the action complete? — Verify repair —
15 Replace the O
2 sensor.
Was the problem solved? — 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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ISUZU KB P190 2007

6E–232 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:
• The engine control module (ECM) and malfunction indicator lamp (MIL = Check Engine Lamp) are
operating correctly.
• There are no Diagnostic Trouble Code(s) stored.
• Tech 2 data is within normal operating range. Refer to Typical Scan Data Values.
• 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:
• ECM grounds for cleanliness, tightness and proper location.
• Vacuum hoses for splits, kinks, and proper connection, shown on the “Emission Control System
Schematics”. Check thoroughly for any type of leak or
restriction.
• Air intake ducts for collapsed or damaged areas.
• Air leaks at throttle body mounting area, manifold absolute pressure (MAP) sensor and intake manifold
sealing surfaces.
• Ignition wires for cracking, harness, and carbon tracking.
• Wiring for proper connections, pinches and cuts.
INTERMITTENT
Important: An intermittent problem may or may not turn
on the malfunction indicator lamp (MIL) or store a
Diagnostic Trouble Code. 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 cased by faulty electrical
connections or wiring. Perform a careful visual/physical
check for the following conditions.
• Poor mating of the connector halves or a terminal not fully seated in the connector (backed out).
• Improperly formed or damaged terminal.
• All connector terminals in the problem circuit should be carefully checked for proper contact tension.
• Poor terminal-to-wire connection. This requires removing the terminal form the connector body to
check.
• Ignition coils shorted to ground and arcing at ignition wires or plugs. • MIL (Check Engine Lamp) wire to ECM shorted to
ground.
• Poor ECM grounds. Refer to the ECM wiring diagrams.
Road test the vehicle with a Digital Multimeter
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.
Using Tech 2 to help detect intermittent conditions. The
Tech 2 has several features that can be used to located
an intermittent condition.
An intermittent MIL (Check Engine Lamp) with no stored
Diagnostic Trouble Code may be caused by the
following:
• Ignition coil shorted to ground and arcing at ignition wires or plugs.
• MIL (Check Engine Lamp) wire to ECM short to ground.
• Poor ECM grounds. Refer to the ECM wiring diagrams.
Check for improper installation of electrical options such
as light, cellular phones, etc. Check all wires from ECM
to the ignition control module for poor connections.
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.
• Check the “Broadcast Code” of the ECM, and compare it with the latest Isuzu service bulletins and/
or Isuzu EEPROM reprogramming equipment to
determine if an update to the ECM’s reprogrammable
memory has been released.
To check the “Broadcast Code”, connect the Tech 2,
then look for “ID info.” then select “Broadcast Code”.
This should display a 4 character code, such as “XBYA”
(example only).
This identifies the contents of the reprogrammable
software and calibration contained in the ECM.
If the “Broadcast Code” is not the most current
available, it is advisable to reprogram the ECM’s
EEPROM memory, which may either help identify a
hard-to find problem or may fix the problem.
The Service Programming System (SPS) will not allow
incorrect software programming or incorrect calibration
changes.

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ENGINE DRIVEABILITY AND EMISSIONS 6E–243
9 Check the fuel pressure. Refer to 6E-108 page“Fuel
System Diagnosis
”.
Was a problem found? — Verify repair Go to Step 10
10 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 11
11 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 12
12 Check items that can cause the engine to run lean. Refer to DTC P1171 “Fuel Supply System Lean
During Power Enrichment”.
Was a problem found? — Verify repair Go to Step 13
13 Check for proper ignition voltage output with the spark tester.
Was a problem found? — Verify repair Go to Step 14
14 Check for a loose ignition control module ground. Was a problem found? — Verify repair Go to Step 15
15 Visually/physically inspect all spark plug high-tension cables. Check for the following conditions:
• Verify that the resistance of all spark plug high- tension cables are less than the specified value.
• Verify that the all spark plug high-tension cables are correctly fitted to eliminate cross-fitting.
• Verify that the all spark plug high-tension cables are not arcing to ground.
Spraying the spark plug high-tension cables with a
light mist of water may help locate an intermittent
problem.
Was a problem found? #1 cyl. 4.4k
Ω
#2 cyl. 3.6k Ω
#3 cyl. 3.1k Ω
#4 cyl. 2.8k ΩVerify repair Go to Step 16
16 1. Check the ignition coil secondary resistance. 2. Replace the coil if it is greater than the specifiedresistance.
Did the coil require replacement? 2.5kΩ Verify repair Go to Step 17
17 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 18
18 1. Check the injector connectors. 2. If any of the connectors are connected at animproper cylinder, connect as necessary.
Was a problem found? — Verify repair Go to Step 19
19 Check the ECM grounds to verify that they are clean and tight. Refer to the ECM wiring diagrams.
Was a problem found? — Verify repair Go to Step 20
20 Visually/physically check the vacuum hose for splits, kinks and proper connections and routing.
Was a problem found? — Verify repair Go to Step 21
Step
Action Value(s) Yes No

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ISUZU KB P190 2007

ENGINE DRIVEABILITY AND EMISSIONS 6E–249
10 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 11
11 Monitor “ B1S1 (Bank 1 Sensor 1) Status ” on the Tech
2.
Is the “ B1S1 (Bank 1 Sensor 1) Status ” in the lean
condition? — Go to Step 12Go to Step 13
12 Check items that can cause the engine to run lean. Refer to DTC P1171 “Fuel Supply System Lean
During Power Enrichment” .
Was a problem found? — Verify repair Go to Step 13
13 1. Visually/physically inspect for the following conditions:
• Restriction of air intake system. Check for a restricted air filter element, or foreign objects
blocking the air intake system.
• Check for objects blocking the IAC passage or throttle bore, excessive deposits in the throttle
bore and on the throttle plate.
• Check for a condition that causes a large vacuum leak, such as an incorrectly installed or
faulty crankcase ventilation hose/brake booster
hose.
Was a problem found? — Verify repair Go to Step 14
14 Check the injector connectors, if any of the injectors are connected an incorrect cylinder, correct as
necessary.
Was a problem found? — Verify repair Go to Step 15
15 Perform the “ Injector Coil/Balance Test” (Refer to 6E-
98 page).
Was a problem found. — Verify repair Go to Step 16
16 1. Check for fuel in the pressure regulator vacuum hose.
2. If fuel is present, replace the fuel pressure regulator assembly.
Was a problem found? — Verify repair Go to Step 17
17 Check for proper ignition voltage output with the spark tester.
Was a problem found? — Verify repair Go to Step 18
18 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 19
Step
Action Value(s) Yes No

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ISUZU KB P190 2007

6E–262 ENGINE DRIVEABILITY AND EMISSIONS
BACKFIRE SYMPTOM
DEFINITIONS: Fuel ignites in the intake manifold, or in the exhaust system, making a loud popping noise.
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 proper ignition voltage output with the spark tester.
Was a problem found? — Verify repair Go to Step 5
5 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 6
6 Visually/physically inspect all spark plug high-tension cables. Check for the following conditions:
• Verify that the resistance of all spark plug high- tension cables are less than the specified value.
• Verify that the all spark plug high-tension cables are correctly fitted to eliminate cross-fitting.
• Verify that the all spark plug high-tension cables are not arcing to ground.
Spraying the spark plug high-tension cables with a
light mist of water may help locate an intermittent
problem.
Was a problem found? #1 cyl. 4.4k
Ω
#2 cyl. 3.6k Ω
#3 cyl. 3.1k Ω
#4 cyl. 2.8k ΩVerify repair Go to Step 7
7 Check the fuel pressure. Refer to 6E-108 page “Fuel
System Diagnosis” .
Was a problem found? — Verify repair Go to Step 8
8 Check for an intermittent ignition system malfunction: • Intermittent CKP 58X signal
• Intermittent ignition feed circuit or sensor ground circuit to the crankshaft position sensor.
Was a problem found? — Verify repair Go to Step 9
9 Refer to 6E-108 page “Fuel System Diagnosis ”　 to
determine if there is a problem with fuel delivery.
Was a problem found? — Verify repair Go to Step 10

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ISUZU KB P190 2007