Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 248

ENGINE DRIVEABILITY AND EMISSIONS

6E–233

Perform the procedure in Fuel System Pressure Test
to determine if there is a problem with fuel delivery.
Was a problem found?

—

Verify repair

Go to Step 18

Check for the following engine mechanical problems
(refer to Engine Mechanical):

• Low compression

• Leaking cylinder head gaskets

• Worn camshaft

• Sticking or leaking valves

• Valve timing

• Broken valve springs

• Camshaft drive belt slipped or stripped
Was a problem found?

—

Verify repair

Go to Step 19

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 20

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 21

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–234

ENGINE DRIVEABILITY AND EMISSIONS

SURGES AND/OR CHUGS SYMPTOM

DEFINITIONS: See the illustration below. Feels like the
vehicle speeds up and slows down with no charge in the
accelerator pedal.

Step

Action

Value(s)

Yes

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

—

Go to Step 2

Go to 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 visual/physical check performed?

—

Go to Step 4

Go to Visual /

physical Check.

Be sure that the driver understands A/C compressor
operation as explained in the owner’s manual. Inform
the customer how the A/C clutch operate.
Is the customer experiencing a normal condition?

—

System OK

Go to Step 5

1. Using a Tech 2, display the MAP sensor value in

comparison with atmosphere temperature.

2. Check for a faulty, plugged, or incorrectly installed

MAP sensor.

Was the problem found?

—

Verify repair

Go to Step 6

Observe the throttle position display on the Tech 2
while slowly increasing throttle pedal.
Is the throttle position at the specified value and
steady in any position?

—

Go to Step 7

Refer to

Diagnostic

Trouble Code

P0123 for

further

diagnosis

Check the knock sensor wire, shield wire, or
installation condition.
Was a problem found?

—

Verify repair

Go to Step 8

Run Engine.
Check the fuel control Heated Oxygen Sensor
(HO2S). When monitored on the Tech 2, the HO2S
should respond quickly to different throttle positions. If
it doesn’t check for silicon or other contaminates from
fuel or use of improper sealant. The sensors may have
a white powdery coating. Silicon contamination sends
a rich exhaust signal which causes the ECM to
command an excessively lean air/fuel mixture.
Was a problem found?

—

Verify repair

Go to Step 9

ENGINE DRIVEABILITY AND EMISSIONS

6E–235

Check the fuel pressure. Refer to Fuel System
Diagnosis.
Was a problem found?

—

Verify repair

Go to Step 10

Monitor “B1S1 (Bank 1 Sensor 1) Status” on the Tech
2.
Is the “B1S1 (Bank 1 Sensor 1) Status” in the rich
condition?

—

Verify repair

Go to Step 11

Check items that can cause the engine to run rich.
Refer to DTC P1167 “Fuel Supply System Rich During
Deceleration Fuel Cut Off”.
Was a problem found?

—

Verify repair

Go to Step 12

Check items that can cause the engine to run lean.
Refer to DTC P1171 “Fuel Supply System Lean
During Power Enrichment”.
Was a problem found?

—

Verify repair

Go to Step 13

Check for proper ignition voltage output with the spark
tester.
Was a problem found?

—

Verify repair

Go to Step 14

Check for a loose ignition control module ground.
Was a problem found?

—

Verify repair

Go to Step 15

Visually/physically inspect all spark plug high-tension
cables. Check for the following conditions:

• Verify that the resistance of all spark plug high-

tension cables are less than the specified value.

• Verify that the all spark plug high-tension cables are

correctly fitted to eliminate cross-fitting.

• Verify that the all spark plug high-tension cables are

not arcing to ground.
Spraying the spark plug high-tension cables with a
light mist of water may help locate an intermittent
problem.

Was a problem found?

#1 cyl. 4.4k

Ω

#2 cyl. 3.6k

Ω

#3 cyl. 3.1k

Ω

#4 cyl. 2.8k

Ω

Verify repair

Go to Step 16

1. Check the ignition coil secondary resistance.

2. Replace the coil if it is greater than the specified

resistance.

Did the coil require replacement?

2.5k

Ω

Verify repair

Go to Step 17

1. Remove the spark plugs and check for gas or oil

fouling cracks, wear, improper gap, burned
electrodes, heavy deposits, or improper heat
range.

2. If spark plugs are fouled, the cause of fouling must

be determined before replacing the spark plugs.

Was a problem found?

—

Verify repair

Go to Step 18

1. Check the injector connectors.

2. If any of the connectors are connected at an

improper cylinder, connect as necessary.

Was a problem found?

—

Verify repair

Go to Step 19

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

—

Verify repair

Go to Step 20

Visually/physically check the vacuum hose for splits,
kinks and proper connections and routing.
Was a problem found?

—

Verify repair

Go to Step 21

Step

Action

Value(s)

Yes

6E–236

ENGINE DRIVEABILITY AND EMISSIONS

Check the exhaust system for a possible restriction:

• Damaged or collapsed pipes

• Internal muffler failure
Was a problem found?

—

Verify repair

Go to Step 22

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 23

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 24

—

Verify Repair

—

Step

Action

Value(s)

Yes

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