2007 ISUZU KB P190 Diagram

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

6E–246 ENGINE DRIVEABILITY AND EMISSIONS
10 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 11Go to Step 12
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 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 19
19 Visually/physically check the vacuum hose for splits, kinks and proper connections and routing.
Was a problem found? — Verify repair Go to Step 20
Step
Action Value(s) Yes No

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ISUZU KB P190 2007

6E–248 ENGINE DRIVEABILITY AND EMISSIONS
CUTS OUT, MISSES SYMPTOM
DEFINITIONS: Steady pulsation or jerking that follows
engine speed; usually more pronounced as engine load
increases.
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 the ECM grounds to verify that they are clean and tight. Refer to the ECM wiring diagrams in
Electrical Diagnosis .
Was a problem found? — Verify repair Go to Step 5
5 Check for a loose or short circuit of ignition coil module voltage feed.
Was a problem found? — Verify repair Go to Step 6
6 Check for a loose or short circuit of ignition coil module ground.
Was a problem found? — Verify repair Go to Step 7
7 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
8 Check the CKP sensor wire, shield wire, or installation condition.
Was a problem found? — Verify repair Go to Step 9
9 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 10Go to Step 11

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ENGINE DRIVEABILITY AND EMISSIONS 6E–251
LACK OF POWER, SLUGGISH OR SPONGY SYMPTOM
DEFINITIONS: Engine delivers less than expected power. Attempting part-throttle acceleration results in little or no
increase in vehicle speed.
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 1. Remove and check the air filter element for dirt or restrictions.
2. Replace the air filter element if necessary.
Was a repair required? — Verify repair Go to Step 5
5 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 6
6 1. Using a Tech 2, display the MAP sensor value in comparison with atmosphere temperature.
2. Check for a faulty, plugged, or incorrectly installed MAP sensor.
Was the problem found? — Verify repair Go to Step 7
7 1. Using a Tech 2, display the ECT sensor and IAT sensor value and warm up condition compared
with the typical data.
2. Check the specified value or wire.
Was the problem found? — Verify repair Go to Step 8
8 Observe the throttle position display on the Tech 2 while slowly increasing throttle pedal.
Does the throttle position increase steady with
increasing smoothly?
—Go to Step 9Refer to
Diagnostic
Trouble Code P0123 for further
diagnosis
9 Check the knock sensor wire, shield wire, or installation condition.
Was a problem found? — Verify repair Go to Step 10
10 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 11
11 Check the fuel pressure. Refer to “Fuel System
Diagnosis
” 6E-108.
Was a problem found? — Verify repair Go to Step 12

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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–1

Section 6B1
Engine Cooling – V6
ATTENTION
Before performing any Service Operation or other procedure described in this Section, refer to 1.1 WARNING,
CAUTION and NOTES for correct workshop practices with regard to safety and/or property damage.
1 General Information ............................................................................................................ ...................3
1.1 WARNING, CAUTION and NOTES ..................................................................................................... ................... 4
1.2 Definition of WARNING, CAUTION and NOTE Statements ......................................................................... .. 4
WARNING defined ............................................................................................................................................. 4
CAUTION defined .............................................................................................................................................. 4
NOTE defined..................................................................................................................................................... 4
2 General Description ............................................................................................................ ...................5
2.1 Radiator Assembly .............................................................................................................. .................................. 5
2.2 Cooling Fan – Standard Specification.................................................................................................................. 7
Overview ................................................................................................................................................................. 7
Cooling Fan and Shroud Assembly ................................................................................................ .................... 8
Fan Motor ........................................................................................................................................................... 8
Fan Operation .................................................................................................................. .................................. 8
V6 Cooling Fan Wiring Diagram .................................................................................................. ....................... 9
Fan Assembly connector .................................................................................................................................. 10
2.3 Coolant Pump....................................................................................................................................................... 10
2.4 Coolant Outlet Housing ......................................................................................................... .............................. 11
2.5 Thermostat ........................................................................................................................................................... 11
2.6 Coolant Filler Cap ............................................................................................................. ................................... 13
2.7 Coolant Recovery Reservoir ..................................................................................................... .......................... 14
2.8 Engine Coolant Temperature Sensor .............................................................................................. ................... 15
3 Service Operations ...............................................................................................................................16
3.1 Service Notes ....................................................................................................................................................... 16
Safety .................................................................................................................................................................... 16
Periodic Servicing............................................................................................................. ................................... 16
Environmental Issues ........................................................................................................... ............................... 16
3.2 Coolant Maintenance ........................................................................................................................................... 17
Topping Up the Cooling System.................................................................................................. ....................... 18
Testing Coolant Concentration........................................................................................................................... 18
Method 1 – Refractometer................................................................................................................................ 18
Method 2 – Hydrometer.................................................................................................................................... 21
3.3 Draining and Filling Cooling System ............................................................................................ ..................... 22
Draining ................................................................................................................................................................ 22
Filling .................................................................................................................................................................... 22
3.4 Cleaning Cooling System ........................................................................................................ ............................ 25
Cooling System Reverse Flush ................................................................................................... ....................... 25
Radiator............................................................................................................................................................ 25
Engine .............................................................................................................................................................. 26
Heater Hoses and Core.......................................................................................................... .......................... 27
3.5 Drive Belt Tension ............................................................................................................................................... 28
Inspect .................................................................................................................................................................. 29
3.6 Coolant Hoses ...................................................................................................................................................... 30
3.7 Pressure Testing ............................................................................................................... ................................... 31
Coolant Filler Cap Pressure Testing ............................................................................................ ...................... 31

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Engine Cooling – V6 Engine Page 6B1–9


V6 Cooling Fan Wiring Diagram

Figure 6B1 – 4

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Engine Management – V6 – Diagnostics Page 6C1-2–1

6C1-2 Engine Management – V6
Diagnostics
ATTENTION
Before performing any service operation or other procedure described in this Section, refer to 1.5 Warning
Caution and Notes for correct workshop practices with regard to safety and/or property damage.
1 General Information ............................................................................................................ ...................4
1.1 Diagnostic System Check ..................................................................................................................................... 4
1.2 Diagnostic Trouble Code Tables ................................................................................................. ......................... 4
1.3 Symptoms Diagnostics ......................................................................................................................................... 5
1.4 Diagnostic Trouble Codes .................................................................................................................................... 5
1.5 Warning Caution and Notes .................................................................................................................................. 6
2 GM LAN Serial Communication Circuit ............................................................................................ ....8
3 Wiring Diagrams and Connector Charts ........................................................................................... ...9
3.1 Wiring Diagrams .................................................................................................................................................... 9
3.2 ECM Connector End Views ................................................................................................................................. 12
3.2 Engine Control Connector End Views ............................................................................................. .................. 16
4 Diagnostics Starting Point...................................................................................................................18
4.1 Basic Requirements ............................................................................................................................................ 18
4.2 Diagnostic Precautions ......................................................................................................... .............................. 18
4.3 Preliminary Checks.............................................................................................................................................. 19
4.4 Diagnostic System Check ........................................................................................................ ........................... 20
5 Symptoms Diagnostics ........................................................................................................................22
5.1 Symptoms Diagnosis Table ....................................................................................................... ......................... 22
5.2 Intermittent Fault Conditions .............................................................................................................................. 22
5.3 Backfire................................................................................................................................................................. 24
5.4 Cranks But Does Not Run ........................................................................................................ ........................... 26
5.5 Cuts Out, Misses.................................................................................................................................................. 27
5.6 Detonation / Spark Knock ....................................................................................................... ............................ 28
5.7 Dieseling, Run-on ................................................................................................................................................ 28
5.8 Hard Start ............................................................................................................................................................. 29
5.9 Hesitation, Sag and Stumble .................................................................................................... .......................... 30
5.10 Lack of Power, Sluggishness or Sponginess ...................................................................................... ............. 31
5.11 Poor Fuel Economy ............................................................................................................................................. 32
5.12 Rough, Unstable, Incorrect Idle or Stalling .................................................................................... ................... 34
5.13 Surges / Chuggles ............................................................................................................................................... 35
6 Functional Checks................................................................................................................................37
6.1 General Information ............................................................................................................ ................................. 37
6.2 Fuel Injector Coil Test ......................................................................................................................................... 37
6.3 Fuel Injector Balance Test ..................................................................................................... ............................. 42
6.4 Fuel Injector Leak Down Test ................................................................................................... .......................... 44
6.5 Alcohol / Contaminants in Fuel Diagnosis ....................................................................................... ................. 46
6.6 Crankshaft Position (CKP) System Variation Learn Procedure..................................................................... .. 46
6.7 Throttle Body Relearn.......................................................................................................................................... 47

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Engine Management – V6 – Diagnostics Page 6C1-2–4

1 General Information
1.1 Diagnostic System Check
The engine management diagnostic procedure is organised in a logical structure that begins with the Diagnostic System
Check. The Diagnostic System Check directs the diagnostic procedure to the logical steps necessary to diagnose an
engine driveability fault condition.
1.2 Diagnostic Trouble Code Tables
The Diagnostic System Check directs the diagnostic procedure to the appropriate diagnostic trouble code (DTC) tables
if there is a DTC currently stored in the engine control module (ECM).
The diagnostic tables locate a faulty circuit or component through a logic based on the process of elimination. These
diagnostic tables are developed with the following assumptions:
• the vehicle functioned correctly at the time of assembly,
• there are no multiple faults, and
• the problem currently exists.
Understanding and the correct use of the diagnostic tables are essential to reduce diagnostic time and to prevent
misdiagnosis.
Multiple DTC Fault Conditions
Some fault conditions trigger multiple component DTCs even if the fault condition exists only on a single component. If
there are multiple DTCs stored in the ECM, the service technician must view and record all DTCs logged.
The relationship between the logged DTCs can then be analysed to determine the source of the fault condition. Always
begin the diagnostic process with the DTC table of the fault condition that may trigger other DTCs to set.
The following fault conditions may trigger multiple DTCs:
• a fault in the serial data communication circuit,
• a system voltage that is too low may cause incorrect engine management system operation or engine
management component malfunction,
• a system voltage that is too high may damage the ECM and/or other engine management components,
• fault condition in the ECM read only memory (ROM) or random access memory (RAM),
• fault condition in the ECM internal circuitry or programming,
• improperly connected sensor or component wiring connector, or
• an electrical fault condition in the following shared ECM electrical circuits trigger DTCs on components or sensors
that share in the faulty shared circuit. Test the electrical circuit of the appropriate sensors or components to isolate
the fault condition. Refer to 3 W iring Diagrams and Connector Charts in this Section.
• 5 V Reference Circuit,
• Low Reference Circuit, or
• Ignition Control Voltage Circuit.
If there are no obvious faults to begin a multiple DTC fault condition diagnostic procedure, diagnose the DTCs in the
following order unless directed otherwise:
1 Always start with the lowest numbered component level DTCs such as:
• sensor DTCs,
• solenoid DTCs, or
• relay DTCs.
2 Then follow with system level DTCs such as:
• misfire DTCs,

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