start ISUZU KB P190 2007 Workshop Repair Manual

Engine Management – V6 – Diagnostics Page 6C1-2–26

5.4 Cranks But Does Not Run
Definition
The engine cranks normally but does not start.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the immobiliser system for correct operation. Refer to 11A Immobiliser.
Sensor / System
• Check the engine coolant temperature (ECT) sensor for an incorrect value.
Compare the engine coolant temperature against the intake air temperature (IAT)
on a cold engine. The ECT and IAT sensor values should be within ± 3°C of each
other. Refer to 6C1-3 Engine Management – V6 – Service Operations for details
of the Temperature vs. Resistance Table.
• Check the mass air flow (MAF) sensor installation. Incorrect installation of the
MAF sensor may cause hard start condition. Refer to 6C1-3 Engine Management
– V6 – Service Operations.
• Check for a dirty starter motor commutator or brushes that can mask the
crankshaft position sensor signal.
Fuel System • Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6.
• restricted fuel filter,
• incorrect fuel pressure,
• contaminated fuel, and
• incorrect fuel pump relay operation.
• Check the operation of the fuel injectors. Refer to 6C1-3 Engine Management –
V6 – Service Operations.
Ignition System • Inspect for moisture or corrosion around the spark plug / ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
Check for loose ignition coil ground circuit.
Engine Mechanical • Check for excessive oil in combustion chamber. Refer to 6A1 Engine Mechanical
– V6.
• Check for the following engine fault conditions. Refer to 6A1 Engine Mechanical –
V6.
• low compression, and
• worn valve train components.
When all diagnosis and repairs are completed, check the system for correct operation.

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Engine Management – V6 – Diagnostics Page 6C1-2–29

Checks Actions
Preliminary Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this Section.
Fuel System Inspect the injectors for leaking condition. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
Engine Cooling System • Check for engine overheating. Refer to 6B1 Engine Cooling – V6.
• Check the engine thermostat for proper operation and correct heat range. Refer to
6B1 Engine Cooling – V6.
Engine Mechanical • Check for build up of carbon deposit in the combustion chamber, which may
cause hot spots and increased compression ratio. Refer to 6A1 Engine
Mechanical – V6.
• Using Tech 2, check for incorrect engine idle speed.
Additional
• If the engine continues to run after the ignition is switched off but the engine runs
normally, check the following:
• ignition switch operation,
• voltage feedback from alternator L terminal to ignition switch, and
• sticking ignition control relay.
When all diagnosis and repairs are completed, check the system for correct operation.
5.8 Hard Start
Definition
The engine cranks normally but takes longer to start than usual. As soon as the engine runs, the engine may stall
immediately.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the immobiliser system for correct operation. Refer to 11A Immobiliser.
Sensor / System
• Check the engine coolant temperature (ECT) sensor for an incorrect value.
Compare the engine coolant temperature against the intake air temperature (IAT)
on a cold engine. The ECT and IAT sensor values should be within ± 3°C of each
other. Refer to 6C1-3 Engine Management – V6 – Service Operations for details
of the Temperature vs. Resistance Table.
• Check the mass air flow (MAF) sensor installation. Incorrect installation of the
MAF sensor may cause hard start condition. Refer to 6C1-3 Engine Management
– V6 – Service Operations.
• Test the resistance of the crankshaft position (CKP) sensor. The CKP sensor
resistance must be within 700 – 1,200 Ω at all temperatures.
• Check for dirty starter motor commutator or brushes that can mask the crankshaft
position sensor signal.
Fuel System • Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C1-3 Engine Management –
V6 – Service Operations.

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Engine Management – V6 – Diagnostics Page 6C1-2–30

Checks Actions
Ignition System
• Inspect for moisture or corrosion around the spark plug / ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Check for loose ignition coil ground circuit.
Engine Mechanical
• Check for excessive oil in combustion chamber. Refer to 6A1 Engine Mechanical
– V6.
• Check for the following engine fault conditions. Refer to 6A1 Engine Mechanical –
V6.
• low compression, and
• worn valve train components.
When all diagnosis and repairs are completed, check the system for correct operation.
5.9 Hesitation, Sag and Stumble
Description
Momentary lack of response or hesitation as the accelerator is depressed. This condition is usually more severe when
first trying to make the vehicle move from a standing start but can occur at any vehicle speed.
Checks Actions
Preliminary • Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this
Section.
• Check the air filter element and intake air ducts for blockages.
Sensor / System
• Using Tech 2, check the heated oxygen sensor (HO2s) operating parameters.
The HO2s should respond quickly to different throttle positions.
• Inspect the accelerator pedal position (APP) sensor harness connector for correct
connection. Poor connection of this connector will not set a DTC.
Fuel System • Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6.
• restricted fuel filter,
• incorrect fuel pressure, and
• contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C Fuel System – V6.
• Perform the fuel injector balance test, refer to 6.3 Fuel Injector Balance
Test in this Section.
• Check for fault conditions that cause an engine to run rich or to run lean.

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Engine Management – V6 – Diagnostics Page 6C1-2–39

Injector Coil Test – With Special Tool J39021
1 Depressurise the fuel system, refer to 6C Fuel System – V6.
2 Turn the ignition OFF.
NOTE
After removing the upper intake manifold, plug
the lower manifold opening to prevent dirt and
other contaminants from entering.
3 Remove the upper intake manifold assembly, refer to 6A1 Engine Mechanical – V6.
4 Using Tech 2, observe the engine coolant temperature (ECT). If the ECT is 10 – 32 °C, refer to Engine Coolant
Temperature Between 10 – 32 °C, or if the ECT is outside this range, refer to Engine Coolant Temperature Outside
10 – 32 °C.
Engine Coolant Temperature Between 10 – 32 °
°°
°
C
Step Action Value(s) Yes No
1 1 Set the amperage supply selector switch on the
fuel injector tester (1), special tool J 39021 to the
Coil Test 0.5 A position. Refer to
Figure 6C1-2 – 11.
2 Connect the fuel injector tester leads (4 and 5) to B+ and ground.
3 Connect the digital multimeter (2) positive and negative lead to the fuel injector tester. Set the
multimeter to read DC Voltage.
4 Connect the fuel injector tester, using fuel injector harness adapter, special tool J44602 to a fuel
injector.
5 Press the Push to Start Test button on the fuel injector tester.
6 Observe and record the voltage reading on the digital multimeter.
NOTE
The voltage reading may rise during the
test. Record the voltage reading after one
second of the test.
7 Repeat steps 4 through 6 for each fuel injector. NOTE
The table in Figure 6C1-2 – 12 shows an
example of the results from a fuel injector
coil test.
Did any fuel injector have an erratic voltage reading
(large fluctuations in voltage that did not stabilise), or
voltage readings outside of the specified value? 5.5 – 6.6 V Replace the faulty
fuel injector/s. Refer to 2.13 Fuel Rail
Assembly, in 6C1-3 Engine
Management – V6 – Service Operations. System OK
When all repairs are completed, check the system for fuel leaks and correct operation.

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Engine Management – V6 – Diagnostics Page 6C1-2–40

Engine Coolant Temperature Outside 10 – 32°
°°
°
C
Step Action Value(s) Yes No
1 1 Set the amperage supply selector switch on the
fuel injector tester (1), special tool J 39021 to the
Coil Test 0.5 A position. Refer to
Figure 6C1-2 – 11.
2 Connect the fuel injector tester leads (4 and 5) to B+ and ground.
3 Connect the digital multimeter (2) positive and negative lead to the fuel injector tester. Set the
multimeter to read DC Voltage.
4 Connect the fuel injector tester, using injector harness adapter, special tool J44602 to a fuel
injector.
5 Press the Push to Start Test button on the fuel injector tester.
6 Observe and record the voltage reading on the digital multimeter.
NOTE
The voltage reading may rise during the
test. Record the voltage reading after one
second of the test.
7 Repeat steps 4 through 6 for each fuel injector.
8 Identify the highest voltage reading recorded from the six fuel injectors tested that is 9.5 V or less.
NOTE
Disregard those voltage readings that are
greater than 9.5 V. Voltage readings greater
than 9.5 V indicate a faulty fuel injector.
9 Subtract the remaining voltage readings recorded in Step 8, from the highest voltage reading.
Are any of the values recorded in Step 9 greater than
the specified value? 0.6 V
Go to Step 2 System OK
2 1 Replace any fuel injector that has any of the
following:
− a subtracted value exceeding 0.6 V,
− an initial reading greater than 9.5 V, and
− an erratic reading.
NOTE
The table in Figure 6C1-2 – 13 shows an
example of the results from a fuel injector
coil test.
Has the repair been completed? – System OK. –
When all repairs are completed, check the system for fuel leaks and correct operation.

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Engine Management – V6 – Diagnostics Page 6C1-2–43

6 Remove the upper intake manifold assembly, refer to 6A1 Engine Mechanical – V6.
NOTE
After removing the upper intake manifold, plug
the lower manifold opening to prevent dirt and
other contaminants from entering.
7 Connect Tool No. J 39021 Fuel Injector Tester (1), and Tool No. J 44602 (3) to the fuel injector connector. Refer to Figure 6C1-2 – 14.

Figure 6C1-2 – 14
Legend
1 Fuel Injector Tester – Special Tool J39021
2 Fuel Pressure Gauge – Special Tool SD28018
3 Fuel Injector Harness Adapter – Special Tool J44602
4 To Battery Positive Terminal 5 Battery Earth
6 First Pressure Reading
7 Second Pressure Reading
8 Connect the fuel injector tester battery positive lead (4) and battery negative lead (5) to the battery, refer to Figure 6C1-2 – 14.
9 Set the amperage supply selector of the fuel injector tester to the Balance Test 0.5 – 2.5 A position.

As the fuel pressure tends to increase after
the fuel injector stops fuel delivery, record the
fuel pressure value immediately after the fuel
injector stops fuel delivery. Do not record the
higher fuel pressure value.
10 Press the Push to Start Test Button on the fuel injector tester to activate the fuel injector.
11 Record the fuel pressure reading indicated by the fuel pressure gauge.
NOTE
The fuel pressure readings taken in Step 10 is
known as the second pressure reading
12 Repeat the balance test pressure reading for each fuel injector.
13 Perform the Fuel Injector Pressure Drop Calculation in this Section.

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Engine Management – V6 – Diagnostics Page 6C1-2–46

6.5 Alcohol / Contaminants in Fuel
Diagnosis
Description
W ater contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or
misfires in one or more cylinders. W ater may collect near a single fuel injector at the lowest point in the fuel rail, and
cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for
rust, or deterioration.
Alcohol (e.g. Ethanol) concentrations more than 10% in the fuel can be detrimental to fuel system components. Alcohol
contamination may cause fuel system corrosion, deterioration of rubber components, and subsequent fuel filter
restriction. Fuel contaminated with alcohol may cause driveability conditions such as hesitation, lack of power, stalling,
or no start. Some types of alcohol are more detrimental to fuel system components than others.
Alcohol in Fuel Testing Procedure
NOTE
The procedures detailed are not intended to be
accurate but rather, indicative of a contamination
situation.
The fuel sample should be drawn from the bottom of the tank so that any water present in the tank will be detected. The
sample should be bright and clear. If alcohol contamination is suspected, then use the following procedure to test the
fuel quality.
• Using a 100 ml graduated cylinder with 1 ml marks, fill the cylinder with fuel to the 90 ml mark.
• Add 10 ml of water to bring the total fluid volume to 100 ml and install a stopper.
• Shake the cylinder vigorously for 10 – 15 seconds.
• Carefully loosen the stopper to release the pressure.
• Re-install the stopper and shake the cylinder vigorously again for 10 – 15 seconds.
• Put the cylinder on a level surface for approximately 5 minutes to allow adequate liquid separation.
If alcohol is present in the fuel, the volume of the lower layer, that now contains both alcohol and water, will be more
than 10 ml. For example, if the volume of the lower layer is increased to 15 ml, this indicates at least 5 percent alcohol in
the fuel. The actual amount of alcohol may be somewhat more because this procedure does not extract all of the
alcohol from the fuel. To obtain an accurate determination of the amount of alcohol contamination in a given fuel sample,
then professional analysis should be sought.
Particulate Contaminants in Fuel Testing Procedure
The fuel sample should be drawn from the bottom of the tank so that any contaminants present in the tank will be
detected. The sample should be bright and clear. If the sample appears cloudy or contaminated with water as indicated
by a water layer at the bottom of the sample, use the following procedure to diagnose the fuel.
• Using an approved fuel container, draw approximately 0.5 litre of fuel.
• Place the cylinder on a level surface for approximately 5 minutes to allow settling of the particulate contamination.
Particulate contamination will show up in various shapes and colours. Sand will typically be identified by a white or light
brown crystals. Rubber will appear as black and irregular particles. If particles are found, clean the entire fuel system
thoroughly. Refer to 6C Fuel System – V6.
6.6 Crankshaft Position (CKP) System
Variation Learn Procedure
Description
The crankshaft position system variation learn feature is carried out automatically on the HFV6 engine under decel with
fuel cut. The road speed and duration of the self-learn process varies with different vehicle equipment levels such as
transmission, final drive ratio etc.
The variation learn procedure cannot be over-written, nor can it be accessed with Tech 2.

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Engine Management – V6 – Diagnostics Page 6C1-2–48

Additional Information
• Use the J 35616-B Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a
component harness connector.
• Inspect the ignition coils for aftermarket devices. An aftermarket device connected to the ignition coil circuits, may
cause a condition with the ignition coils.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
4 The ignition coils for each bank are fused separately. If a fuse opens or the ignition 1 voltage circuit opens between the fuse and the splice, all the ignition coils for one bank of the engine would be inoperative. If the ground
circuit opens at the engine block, the ignition coils would be inoperative for one bank of the engine.
5 This step tests for an open or a high resistance in the ignition 1 voltage circuit of the ignition coil. If the DMM does not display near battery voltage there is an open or a high resistance in the circuit.
6 This step determines if the ground circuit is open. If the circuit is open, the ignition coils would be inoperative for one bank of the engine.
7 This step determines if the ignition 1 voltage circuit is shorted to ground. If the fuse is open, the ignition coils would be inoperative for one bank of the engine.
Diagnostic Table
Step Action Value(s) Yes No
1
Has the Diagnostic System Check been performed? —
Go to Step 2 Refer to
4.4 Diagnostic System Check
2 W ere you sent here from DTC P0300 or P0301-P0306? —
Go to Step 3 Go to DTC P0300 or
DTC P0301 – P0306
3 1 Start the engine.
2 Allow the engine to reach operating temperature.
3 Operate the engine at 2,000 rpm.
4 Monitor all of the Misfire Current Counters with a scan tool. There are a total of 6 counters,
1 counter per cylinder.
Are any of the Misfire Current Counters incrementing? —
Go to Step 4 Go to
5.2 Intermittent Fault Conditions
4 Are all the misfire counters incrementing for one bank
of the engine? —
Go to Step 7 Go to Step 5
5 1 Ignition OFF.
2 Disconnect the appropriate ignition coil.
3 Ignition ON, engine OFF.
4 Connect a test lamp between the battery voltage circuit of the ignition coil and a good ground.
5 Measure the voltage between the probe of the test lamp and a good ground with a DMM. Refer
to 8A Electrical - Body and Chassis for the
procedure to measure voltage drop.
Is the voltage at the specified value? B+
Go to Step 6 Go to Step 9

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Engine Management – V6 – Diagnostics Page 6C1-2–49

6 1 Connect the test lamp between the battery
voltage circuit of the ignition coil and to each
ground circuit of the ignition coil.
Does the test lamp illuminate at each ground circuit? —
Go to Step 8 Go to Step 10
7 1 Test the battery voltage circuit for an open or high
resistance at the splice of the affected bank of
ignition coils. Refer to 8A Electrical - Body and
Chassis for circuit testing procedures.
Did you find and correct the condition? —
Go to Step 12 Go to Step 10
8 1 Test for an intermittent and for a poor connection
at the ignition coil. Refer to 8A Electrical - Body
and Chassis for circuit testing procedures.
Did you find and correct the condition? —
Go to Step 12 Go to Step 11
9 NOTE
The battery voltage circuit is shared with
other components. Disconnecting a
component on the shared battery voltage
circuit may isolate a shorted component.
Review the electrical schematic and
diagnose the shared circuits and
components.
1 Repair a short to ground, an open or high resistance in the ignition 1 voltage circuit. Refer to
Refer to 8A Electrical - Body and Chassis for
wiring repair procedures.
2 Replace the fuse as necessary.
Did you complete the repair? —
Go to Step 12 —
10 1 Repair the open or high resistance in the ground
circuit. Refer to 8A Electrical - Body and Chassis
for wiring repair procedures.
Did you complete the repair? —
Go to Step 12 —
11 1 Replace the ignition coil. Refer to 2.15 Ignition
Coils, in 6C1-3 Engine Management – V6 –
Service Operations.
Did you complete the replacement? —
Go to Step 12 —
12 1 Connect all disconnected components.
2 Use Tech 2 to clear the DTC/s.
3 Start the engine.
4 Observe the Capture Info with Tech 2.
Do any of the misfire counters increment? —
Go to Step 2 Go to Step 13
13 1 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? — Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, clear all DTCs and verify correct operation


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Engine Management – V6 – Diagnostics Page 6C1-2–56

DTC Description Diagnostic Table
P0522 Oil Pressure Sensor Voltage Low 7.31 DTC P0521, P0522 or P0523
P0523 Oil Pressure Sensor Voltage High 7.31 DTC P0521, P0522 or P0523
P0532 A/C Pressure Sensor Voltage Low 7.32 DTC P0532 or P0533
P0533 A/C Pressure Sensor Voltage High 7.32 DTC P0532 or P0533
P0560 System Voltage Malfunction 7.33 DTC P0560, P0562 or P0563
P0562 System Voltage Low Voltage 7.33 DTC P0560, P0562 or P0563
P0563 System Voltage High Voltage 7.33 DTC P0560, P0562 or P0563
P0571 Cruise Control Brake Switch Circuit 7.28 DTC P0504 or P0571
P0601 Replace Electronic Control Unit (ECU) 7.34 DTC P0601, P0602, P0604 or P0606
P0602 Program Electronic Control Unit (ECU) 7.34 DTC P0601, P0602, P0604 or P0606
P0604 Replace Electronic Control Unit (ECU) 7.34 DTC P0601, P0602, P0604 or P0606
P0606 Replace Electronic Control Unit (ECU) 7.34 DTC P0601, P0602, P0604 or P0606
P0615 Starter Relay Circuit Malfunction 7.35 DTC P0615, P0616 or P0617
P0616 Starter Relay Circuit Low Voltage 7.35 DTC P0615, P0616 or P0617
P0617 Starter Relay Circuit High Voltage 7.35 DTC P0615, P0616 or P0617
P0625 Alternator F Terminal Low Voltage 7.36 DTC P0625 or P0626
P0626 Alternator F Terminal High Voltage 7.36 DTC P0625 or P0626
P0627 Fuel Pump Relay Circuit Malfunction 7.37 DTC P0627, P0628 or P0629
P0628 Fuel Pump Relay Voltage Low 7.37 DTC P0627, P0628 or P0629
P0629 Fuel Pump Relay Voltage High 7.37 DTC P0627, P0628 or P0629
P0633 Immobiliser Function Not Programmed 7.30 DTC P0513, P0633, P1629, P1632,
P1677, P1678 or P1679
P0638 Commanded Versus Actual Throttle Position Correlation 7.29 DTC P0506, P0507, P0638, P1551, P2100, P2101, P2119 or P2176
P0645 A/C Relay Circuit Malfunction 7.38 DTC P0645, P0646 or P0647
P0646 A/C Relay Voltage Low 7.38 DTC P0645, P0646 or P0647
P0647 A/C Relay Voltage High 7.38 DTC P0645, P0646 or P0647
P0685 Engine Control Ignition Relay Circuit Malfunction 7.39 DTC P0685, P0686 or P0687
P0686 Engine Control Ignition Relay Circuit Low Voltage 7.39 DTC P0685, P0686 or P0687
P0687 Engine Control Ignition Relay Circuit High Voltage 7.39 DTC P0685, P0686 or P0687
P0691 Cooling Fan Relay 1 Circuit Low Voltage 7.26 DTC P0480, P0691 or P0692
P0692 Cooling Fan Relay 1 Circuit High Voltage 7.26 DTC P0480, P0691 or P0692
P0700 Malfunction Indicator (MI) Request from Transmission
Control Module (TCM) 7.40 DTC P0700
P0704 Clutch Switch Input Circuit Malfunction
7.41 DTC P0704
P0850 Park / Neutral Signal Circuit Incorrect Signal 7.42 DTC P0850
P1258 Engine Coolant Over Temperature – Protection Mode
Active 7.8 DTC P0116, P0117, P0118, P0125 or
P1258
P1551 Throttle Control Lower Position Not Reached during Learning Mode 7.29 DTC P0506, P0507, P0638, P1551,
P2100, P2101, P2119 or P2176

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