Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 90

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

6E–355

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 30

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 31

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 32

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 33

Go to Step 34

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

—

Step

Action

Value(s)

Yes

6E–356

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

Replace the injection pump assembly.
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

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

6E–357

CUTS OUT, MISSES SYMPTOM

DEFINITIONS: Steady pulsation or jerking that follows
engine speed; usually more pronounced as engine load
increases.

time

rpm

Step

Action

Value(s)

Yes

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2

Go to On Board

Diagnostic

(OBD) System

Check

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

Was a visually/physical check performed?

—

Go to Step 4

Go to Visual /

physical Check

Is the customer using the incorrect fuel type?

Diesel fuel

only

Replace with

diesel fuel

Go to Step 5

Visually/physically inspect for the following conditions.

• Restrict air intake system. Check for a restricted air

filter element, or foreign objects blocking the air
intake system

• Check for objects blocking or excessive deposits in

the throttle bore and on the throttle plate

• Check for a condition that causes a large vacuum

leak, such as an incorrectly installed or faulty
crankcase ventilation hose.

• Restrict air intake system at the turbocharger.

Check for objects blocking the turbocharger
compressor

wheel or turbine shaft sticking.
If a problem is found, repair as necessary.
Was a problem found?

—

Verify repair

Go to Step 6

Check the ECM & PSG grounds to verify that they are
clean and tight. Refer to the ECM wiring diagrams.
Was a problem found?

—

Verify repair

Go to Step 7

6E–358

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

1. Using the Tech 2, perform test drive.

2. Monitor the “Vehicle Speed” in the data display.

Does the Tech 2 indicate correct “Vehicle Speed”
depending on driving speed?

—

Go to Step 11

Go to Step 8

Check the VSS 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 9

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

—

Go to Step 10

Go to Step 31

Replace the VSS assembly.
Is the action complete?

—

Verify repair

—

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 16

Go to Step 12

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 13

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 14

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

—

Go to Step 15

Go to Step 31

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

—

Verify repair

—

Step

Action

Value(s)

Yes

When constant vehicle speed

High

Correct Speed

Low

Time

Unstable Data

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