2007 ISUZU KB P190 coolant

Engine Management – V6 – Diagnostics Page 6C1-2–37

6 Functional Checks
6.1 General Information
The items detailed in the following pages are to be used when there is a customer complaint and there are no diagnostic
trouble codes set, or one or more of the Tech 2 data values are not within the typical values. They are also to be used
when instructed from a DTC table. Before using these tables, you should refer to 5 Symptoms Diagnostics in this
Section, which may direct you to using the following functional checks.
The purpose of these tables is to diagnose engine control module (ECM) controlled components or sub-systems that do
not have diagnostic trouble codes assigned to them. Another purpose of these tables is for Technicians who feel
confident that a particular part of the sub-system is not operating properly and wants only to check that particular item
for proper operation without going through lengthy diagnostic procedures.
6.2 Fuel Injector Coil Test
The fuel injector coil test is divided into two parts. Begin by performing the fuel injector coil quick test. Then only perform
the Injector Coil Test – W ith Special Tool J39021 procedure if the quick test determines that there is a faulty fuel injector.
Fuel Injector Coil Quick Test
Test Description
The following numbers refer to the step numbers in the diagnostic table:
1 This step checks if the engine coolant temperature is within the correct range.
2 This step tests each fuel injector resistance within a specific temperature range.
3 This step determines if all of the fuel injectors are within 3 ohms of each other.
Step Action Value(s) Yes No
1 Using Tech 2, observe the engine coolant temperature
(ECT).
Is the ECT within the specified range? 10 – 32 °C Go to Step 2 Go to Step 3
2 1 Disconnect the fuel injector harness connector,
refer to 2.13 Fuel Rail Assembly, in 6C1-3 Engine
Management – V6 – Service Operations.
2 Using a digital ohmmeter and connector test adaptor kit J 35616-A, measure the resistance of
each fuel injector between the ignition voltage
circuit and the fuel injector control circuit. Refer to
8A Electrical - Body and Chassis for information
on testing for continuity and to Figure 6C1-2 – 9
and Figure 6C1-2 – 10 for the fuel injector
harness connector.
Do any of the fuel injectors display a resistance outside
the specified range? 11 – 14 ΩRefer to Injector
Coil Test – W ith
Special Tool J39021 in this Section Injectors OK

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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 6C1-2–41


Figure 6C1-2 – 11
Legend
1 Fuel Injector Tester – Special Tool J39021
2 Digital Multimeter
3 Fuel Injector Harness Adapter – Special Tool J44602 4 To Battery Positive Terminal
5 Battery Earth


Fuel Injector Coil Test Example – Engine Coolant Temperature 10 – 32 °
°°
°
C (Typical Values Shown)
Fuel Injector No. Voltage Reading Pass / Fail (acceptable range 5.5 - 6.6 V)
1 6.6 Pass
2 5.4 Fail
3 6.2 Pass
4 6.1 Pass
5 6.7 Fail
6 6.0 Pass
Figure 6C1-2 – 12
Fuel Injector Coil Test Example – Engine Coolant Temperature Greater / Less Than 10 – 32 °
°°
°
C (Typical Values
Shown)
Fuel Injector No. Voltage Reading Highest Voltage Reading (9.5 V or less) Subtracted Value
(acceptable voltage 0.6 V) Pass / Fail
1 9.8 – – Fail
2 6.4 7.0 0.6 Pass
3 6.9 7.0 0.1 Pass
4 5.8 7.0 1.2 Fail
5 7.0 7.0 0.0 Pass
6 6.3 7.0 0.7 Fail
Figure 6C1-2 – 13

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Engine Management – V6 – Diagnostics Page 6C1-2–42

6.3 Fuel Injector Balance Test

To avoid irregular fuel pressure readings, do
not perform this procedure if the engine
coolant temperature is greater than 94 °
°°
°
C.
Fuel Injector Balance Test – With Tech 2
1 Check the engine coolant temperature is less than 94 °C.
2 Perform the fuel injector coil test and replace any fuel injectors that are not functioning correctly before proceeding. Refer to 6.2 Fuel Injector Coil Test.
3 Perform the fuel system pressure check and ensure the fuel system is functioning correctly before proceeding with the fuel injector balance test. Refer to 6C Fuel System – V6.
4 W hile the fuel pressure gauge is still connected to the fuel pressure test point, pressurise the fuel system. Refer to 6C Fuel System – V6.
5 W hen the fuel pressure reading stabilises, record the fuel pressure reading indicated by the fuel pressure gauge.
NOTE
The fuel pressure reading taken in Step 5 is
known as the first pressure reading.
6 Connect Tech 2 to the data link connector (DLC) and turn the ignition on.
7 On Tech 2 select Engine / V6 Engine / Actuator Test / Fuel Injector Balance .
8 Follow the Tech 2 prompts, recording the fuel pressure gauge reading for each injector.
NOTE
The fuel pressure readings taken in Step 8 are
known as the second pressure reading
9 Perform the Fuel Injector Pressure Drop Calculation in this Section.
Fuel Injector Balance Test – Without Tech 2
1 Check the engine coolant temperature is less than 94 °C.
2 Perform the fuel injector coil test and replace any fuel injectors that are not functioning correctly before proceeding. Refer to 6.2 Fuel Injector Coil Test.
3 Perform the fuel system pressure check and ensure the fuel system is functioning correctly before proceeding with the fuel injector balance test. Refer to 6C Fuel System – V6.
4 W hile the fuel pressure gauge is still connected to the fuel pressure test point, pressurise the fuel system. Refer to 6C Fuel System – V6.
5 W hen the fuel pressure reading stabilises, record the fuel pressure reading indicated by the fuel pressure gauge.
NOTE
The fuel pressure reading taken in Step 5 is
known as the first pressure reading.

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Engine Management – V6 – Diagnostics Page 6C1-2–47

6.7 Throttle Body Relearn
A throttle body relearn procedure is performed in one of two ways:
• Engine Control Module initiated throttle body relearn, or
• Tech 2 initiated throttle body relearn.
Engine Control Module Throttle Body Relearn
The engine control module (ECM) will automatically perform a throttle body relearn procedure if either of the following
conditions exist:
• The battery has been disconnected, or
• The ignition switch is in the ON position for greater than 29 seconds, and the following conditions are met:
− Engine speed is less than 40 rpm,
− Vehicle speed is 0 km/h,
− Engine coolant temperature is 5 – 60°C,
− Intake air temperature is 5 – 60°C,
− Accelerator pedal position sensor angle is less than 14.9%, and
− Ignition voltage is greater than 10 V.
Tech 2 Throttle Body Relearn
To perform a throttle body relearn using Tech 2, complete the following procedure:
NOTE
Tech 2 will not initiate a throttle body relearn if
the engine is running.
1 Connect Tech 2 to the data link connector (DLC) and turn the ignition on.
2 On Tech 2 select Engine / Programming / Throttle Body Relearn.
3 W hen Tech 2 displays ‘Do you really want to Reset?’, press the ‘Yes’ soft key.
4 W hen Tech 2 displays ‘Programming Completed’, and the electronic throttle control value displayed by Tech 2 is ‘11’, press the ‘Confirm’ soft key to return to the Tech 2 Programming screen.
5 The throttle body relearn is now complete.
6.8 Electronic Ignition (EI) System Diagnosis
Circuit Description
The engine control module (ECM) controls the ignition coils by pulsing the ignition control (IC) circuits, which triggers an
ignition coil and fires the spark plug. The ECM controls the sequencing and the timing of each ignition coil. The ignition
system consist of the following components:
• The six ignition coils
• The crankshaft position (CKP) sensor
• The four camshaft position (CMP) sensors
• The ECM
The ignition coils use the following circuits:
• An IC circuit
• An ignition 1 voltage circuit
• Two ground circuits

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Engine Management – V6 – Diagnostics Page 6C1-2–51

DTC Description Diagnostic Table
P0058 O2 Sensor Heater Circuit High Voltage (Bank 2, Sensor 2) 7.3 DTC P0030, P0031, P0032, P0036,
P0037, P0038, P0050, P0051, P0052,
P0056, P0057 or P0058
P0059 O2 Sensor Heater Resistance Range / Performance (Bank 2, Sensor 1) 7.5 DTC P0053 or P0059
P0101 Mass Air Flow Sensor Circuit Range / Performance 7.6 DTC P0101, P0102 or P0103
P0102 Mass Air Flow Sensor Voltage Low
7.6 DTC P0101, P0102 or P0103
P0103 Mass Air Flow Sensor Voltage High 7.6 DTC P0101, P0102 or P0103
P0112 Intake Air Temperature Sensor Circuit Low Voltage 7.7 DTC P0112 or P0113
P0113 Intake Air Temperature Sensor Circuit High Voltage 7.7 DTC P0112 or P0113
P0116 Engine Coolant Temperature Sensor Circuit Range /
Performance 7.8 DTC P0116, P0117, P0118, P0125 or
P1258
P0117 Engine Coolant Temperature Sensor Circuit Low Voltage 7.8 DTC P0116, P0117, P0118, P0125 or P1258
P0118 Engine Coolant Temperature Sensor Circuit High Voltage 7.8 DTC P0116, P0117, P0118, P0125 or P1258
P0121 Throttle Position Sensor 1 Circuit Range / Performance 7.9 DTC P0121, P0122, P0123, P0221, P0222,or P0223
P0122 Throttle Position Sensor 1 Circuit Low Voltage 7.9 DTC P0121, P0122, P0123, P0221,
P0222,or P0223
P0123 Throttle Position Sensor 1 Circuit High Voltage 7.9 DTC P0121, P0122, P0123, P0221,
P0222,or P0223
P0125 Insufficient Engine Coolant Temperature For Closed Loop Fuel Control 7.8 DTC P0116, P0117, P0118, P0125 or
P1258
P0130 O2 Sensor Circuit Malfunction (Bank 1, Sensor 1) 7.10 DTC P0130, P0131, P0132, P0135, P0137, P0138, P0140, P0141, P0150
P0151, P0152, P0155, P0157, P0158,
P0160, P0161, P2243, P2247, P2270,
P2271, P2272, P2273, P2297 or P2298
P0131 O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1) 7.10 DTC P0130, P0131, P0132, P0135, P0137, P0138, P0140, P0141, P0150
P0151, P0152, P0155, P0157, P0158,
P0160, P0161, P2243, P2247, P2270,
P2271, P2272, P2273, P2297 or P2298
P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1) 7.10 DTC P0130, P0131, P0132, P0135, P0137, P0138, P0140, P0141, P0150
P0151, P0152, P0155, P0157, P0158,
P0160, P0161, P2243, P2247, P2270,
P2271, P2272, P2273, P2297 or P2298
P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1) 7.11 DTC P0133 or P0153
P0135 O2 Sensor Heater Circuit Range / Performance (Bank 1, Sensor 1) 7.10 DTC P0130, P0131, P0132, P0135,
P0137, P0138, P0140, P0141, P0150
P0151, P0152, P0155, P0157, P0158,
P0160, P0161, P2243, P2247, P2270,
P2271, P2272, P2273, P2297 or P2298
P0137 O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2) 7.10 DTC P0130, P0131, P0132, P0135, P0137, P0138, P0140, P0141, P0150
P0151, P0152, P0155, P0157, P0158,
P0160, P0161, P2243, P2247, P2270,
P2271, P2272, P2273, P2297 or P2298

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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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