Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 88

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–347

1. Using the Tech 2, display the ECT sensor and IAT

sensor value.

2. Check the displayed value.

Does the Tech 2 indicate correct temperature
depending on engine condition?
If a problem is found, repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 9

1. Using the Tech 2, ignition “On” and engine “Run”.

2. Monitor the “Mass Air Flow” in the data display.

Does the Tech 2 indicate correct “Mass Air Flow”
depending on accelerator pedal operation?

—

Go to Step 14

Go to Step 10

Remove the MAF & IAT sensor assembly and check
for the following conditions.

• Objects blocking at the MAF sensor element.
If a problem is found, repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 11

Check the MAF sensor harness for the following
conditions.

• Check for poor connector connection.

• Check for misrouted harness.

• Check for any accessory parts which may cause

electric interference.

If a problem is found, repair as necessary.
Was a problem found?

—

Verify repair

Go to Step 12

Substitute a known good MAF & IAT sensor assembly
and recheck.
Was the problem solved?

—

Go to Step 13

Go to Step 29

Replace the MAF & IAT sensor assembly.
Is the action complete?

—

Verify repair

—

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Monitor the “Pedal/Throttle Position” and “Idle

Switch” in the data display.

Does the Tech 2 indicate correct “Pedal/Throttle
Position” from 0% to 100% and correct “Idle Switch”
status depending on accelerator pedal operation?

—

Go to Step 19

Go to Step 15

1. Using the Tech 2, ignition “On” and engine “Off”.

2. Monitor the “Pedal/Throttle Position” and “Idle

Switch” in the data display.

3. Adjust the accelerator cable or TPS within 0% to

100%.

Was the problem solved?

—

Verify repair

Go to Step 16

Check the TPS harness for the following conditions.

• Check for poor connector connection.

• Check for misrouted harness.

• Check for any accessory parts which may cause

electric interference.

If a problem is found, repair as necessary.
Was a problem found?

—

Verify repair

Go to Step 17

Substitute a known good TPS and recheck.
Was the problem solved?

—

Go to Step 18

Go to Step 29

Replace the TPS.
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

6E–348

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

Remove the CKP sensor from the flywheel housing
and check for the following conditions.

• Objects sticking the CKP sensor.

• Objects sticking the CKP sensor pulser.
If a problem is found, repair as necessary.
Was the problem found?

—

Verify repair

Go to Step 20

Check the CKP sensor harness for the following
conditions.

• Check for poor connector connection.

• Check for misrouted harness.

• Check for any accessory parts which may cause

electric interference.

If a problem is found, repair as necessary.
Was a problem found?

—

Verify repair

Go to Step 21

Substitute a known good CKP sensor and recheck.
Was the problem solved?

—

Go to Step 22

Go to Step 23

Replace the CKP sensor.
Is the action complete?

—

Verify repair

—

1. Using the Tech 2 and ignition “On” and engine

“Run”.

2. Monitor the following parameters in the data

display.

• “Desired Injection Quantity” & “Injection Quantity”

• “Desired Injection Start” & “Actual Injection Start”
Are the large gap or unstable parameter displayed
between “Desired” and “Actual”?

—

Go to Step 25

Go to Step 24

Using the vacuum pump and check the EGR valve (if
equipped) operation for the following condition through
the small window.

• Restrict shaft movement. Check for objects sticking

the shaft, broken diaphragm or excessive carbon
deposit.

If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to Step 25

Step

Action

Value(s)

Yes

When idling or part-throttle When accelerated

High

Desired

Low

Time

Actual

High

Low

Desired

Actual

Time

Vacuum Pump

Small Window

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–349

Visually/physically inspect for the following conditions.

• Restrict fuel supply system. Check for a pinched

fuel hose/pipe.

• Check for a condition that causes fuel waxing or

icing, such as the customer is using an incorrect
fuel type in winter season or water mixed with the
fuel.

If a problem is found, repair as necessary.
Was a problem found?

—

Verify repair

Go to Step 26

Replace the fuel filter.
Was the problem solved?

—

Verify repair

Go to Step 27

Remove the eye bolt with gauze filter from the
injection pump and check for the following conditions.

• Objects blocking at the gauze filter. Check for a

condition that causes contaminated fuel, such as
the customer is using an aftermarket fuel filter or
extended maintenance interval.

• Check for a condition that causes fuel waxing or

icing, such as the customer is using an incorrect
fuel type in winter season or water mixed with the
fuel.

If a problem is found, repair as necessary.
Was the problem found?

—

Replace the eye

bolt with gauze

filter and verify

repair

Go to Step 28

1. Review all diagnostic procedures within this table.

2. If all procedures have been completed and no

malfunctions have been found, review/inspect the
following:

• Visual/physical inspection

• Tech 2 data

• All electrical connections within a suspected circuit

and/or system

Was a problem found?

—

Verify repair

Go to Step 29

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 30

Step

Action

Value(s)

Yes

6E–350

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

Substitute a known good ECM and recheck.
Was the problem solved?
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual.
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure.

—

Go to Step 31

Go to Step 32

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 immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure.

—

Verify repair

—

Replace the injection pump assembly.
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

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