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Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 872

6E–512

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Hesitation, Sag, Stumble Symptom

(Cont'd)

Step

Yes

Value(s)

Action

1. Visually/physically check vacuum hoses for splits,

kinks, and proper connections and routing as
shown on the “Vehicle Emission Control
Information” label.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to

Step 18

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

Freeze Frame data/Failure Records butter

All electrical connections within a suspected
circuit and/or system

3. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Contact

Technical

Assistance

6E–513

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Bank 1 Restricted Exhaust System Check

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

1. Remove the Bank 1 HO2S 2.
2. Install the Exhaust Backpressure Tester

(BT-8515-V or equivalent) in place of the Bank 1
HO2S 2.

3. Run the engine at normal operating temperature.
4. Increase the engine speed to 2000 RPM and allow

10 seconds for pressure to build.

5. Observe the exhaust system backpressure reading

on the gauge.

Does the reading exceed the amount in the value
column?

8.62 kPa

(1.25 psi)

Go to

Step 3

Go to

Step 4

Repair the restriction in the exhaust system after the
catalytic converter.
Possible faults include:

Collapsed pipe

Heat distress

Internal muffler failure

Is the action complete?

—

Verify repair

—

1. Install the Bank 1 HO2S 2.
2. Install the Exhaust Backpressure Tester in place of

Bank 1 HO2S 1.

3. Run the engine at normal operating temperature.
4. Increase the engine speed to 2000 RPM and allow

10 seconds for pressure to build.

5. Observe the exhaust system backpressure reading

on the gauge.

Does the reading exceed the amount in the value
column?

8.62 kPa

(1.25 psi)

Go to

Step 5

No trouble

found. If a
driveability

symptom

exists, refer
to symptom

charts

Repair the restriction in the catalytic converter.

Is the action complete?

—

Verify repair

—

NOTE: DTCs will be set by running the vehicle to normal
operating temperature after a cold start with the O2
sensor disconnected. After performing these tests, use
the Tech 2 to erase the DTCs that were set by the lack of
O2 sensor activity.

6E–514

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Bank 2 Restricted Exhaust System Check

Step

Action

Value(s)

Yes

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

—

Go to

Step 2

Go to

OBD

System

Check

1. Remove the Bank 2 HO2S 2.
2. Install the Exhaust Backpressure Tester

(BT-8515-V or equivalent) in place of the Bank 2
HO2S 2.

3. Run the engine at normal operating temperature.
4. Increase the engine speed to 2000 RPM and allow

10 seconds for pressure to build.

5. Observe the exhaust system backpressure reading

on the gauge.

Does the reading exceed the amount in the value
column?

8.62 kPa

(1.25 psi)

Go to

Step 3

Go to

Step 4

Repair the restriction in the exhaust system after the
catalytic converter.
Possible faults include:

Collapsed pipe

Heat distress

Internal muffler failure

Is the action complete?

—

Verify repair

—

1. Install the Bank 2 HO2S 2.
2. Install the Exhaust Back pressure Tester in place of

Bank 1 HO2S 1.

3. Run the engine at normal operating temperature.
4. Increase the engine speed to 2000 RPM and allow

10 seconds for pressure to build.

5. Observe the exhaust system backpressure reading

on the gauge.

Does the reading exceed the amount in the value
column?

8.62 kPa

(1.25 psi)

Go to

Step 5

No trouble

found. If a
driveability

symptom

exists, refer
to symptom

charts

Repair the restriction in the catalytic converter.

Is the action complete?

—

Verify repair

—

6E–515

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Default Matrix Table

Service Procedure Default Strategy

A referral strategy has been established to assist the
technician with additional information when the cause of
the failure cannot be determined. If no problem is found
after performing diagnostics, then refer to the default
matrix table for further diagnostic information.

Default Matrix Table

Strategy Based Diagnostic Charts

Initial Diagnosis

Default Section(s)

On-Board Diagnostic (OBD) System
Check

Vehicle does not enter diagnostics.

Chassis Electrical

On-Board Diagnostic (OBD) System
Check

Vehicle enters diagnostics and
communicates with the Tech 2. MIL is
“ON” in diagnostics. Engine does not
start and run.

Ignition System Check

On-Board Diagnostic (OBD) System
Check

Engine starts and runs, no PCM
codes set. Customer complains of
vibration.

—

On-Board Diagnostic (OBD) System
Check

Engine starts and runs, no PCM
codes set. Customer complains of
harsh or soft shift, poor performance,
delayed or no engagement into drive
or reverse, transmission fluid leak,
transmission noise or vibration, or
improper TCC operation.

Automatic Transmission

PCM Power and Ground Check

On-Board Diagnostic (OBD) System
Check.

Chassis Electrical

PCM Power and Ground Check

On-Board Diagnostic (OBD) System
Check. PCM power and ground
circuits OK. Data link voltage
incorrect.

Chassis Electrical

On-Board Diagnostic (OBD) System
Check

Automatic Transmission

Symptoms

Initial Diagnosis

Default Section(s)

Intermittents

1. On-board Diagnostic (OBD)

system check.

2. Careful visual/physical

inspections.

Chassis Electrical

Hard Starts

1. OBD system check.
2. ETC system check.
3. Sensors (ECT, MAP, MAF, TP) ;

MAP output chart.

4. Fuel system electrical test, fuel

system diagnosis.

5. Ignition system.

Engine Mechanical, Ignition
System Check, Exhaust System
Diagnosis

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