Isuzu KB P190. Manual — part 829

Engine Management – V6 – Diagnostics

Page 6C1-2–38

Step Action Value(s)

Yes

No

3

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.

3

Record each fuel injector value.

4

Subtract the lowest resistance value from the
highest.

Is the difference equal to, or less than, the specified
value?

3

Ω

Injectors OK

Refer to Injector
Coil Test – With

Special Tool J39021

in this Section.

Figure 6C1-2 – 9

Fuel Injector Harness to Engine Harness Connector

Pin Description

Pin Function

Circuit

Number

1

Ignition Voltage Circuit – Cyl. 1, 3, 5

639

2

Ignition Voltage Circuit – Cyl. 2, 4, 6

1039

3

Injector 1 Control Circuit

1744

4

Injector 3 Control Circuit

1746

5

Injector 5 Control Circuit

845

6

Injector 2 Control Circuit

1745

7

Injector 4 Control Circuit

844

8

Injector 6 Control Circuit

846

Figure 6C1-2 – 10

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.

N O T E

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.

N O T E

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.

N O T E

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.

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.

N O T E

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.

N O T E

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.

N O T E

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.

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