Isuzu Trooper (1998-2002 year). Manual - part 481

 

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Isuzu Trooper (1998-2002 year). Manual - part 481

 

 

6E–294

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

D

DTC P0430 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

Check for the following conditions:

D

Poor connection at PCM – Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.

D

Damaged harness – Inspect the wiring harness for
damage.  If the harness appears to be OK, observe the
display on the Tech 2 while moving connectors and
wiring harnesses related to the sensor.  A change in the
display will indicate the location of the fault.

Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs.  This
may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart.
7. Difficulty completing the DTC P0430 “Status This

Ign”, test may be encountered in areas where test
conditions cannot be maintained easily, especially in
urban areas.  To minimize the amount of driving
required to complete the DTC P0430 “Status This
Ign”, test, use the following procedure:

D

Allow the engine to warm up completely.

D

With the vehicle in “Park”, monitor mass air flow on
the Tech 2 and hold part throttle to maintain a
reading of over 12 g/second for at least 2 minutes.
This will achieve the “warm catalyst” required for
running the test.

D

Operate the vehicle in second or third gear to remain
in the DTC P0430 test conditions described in
“Conditions for Setting the DTC” as much as
possible.  If you must stop the vehicle, maintain the
“warm catalyst” criteria as follows:
– Place the vehicle in “Park” or “Neutral”,
– Hold part throttle to maintain a mass air flow

reading of over 15 g/second for the duration of the
stop.

The “TWC Monitor Test Counter” displayed on the Tech 2
may be used to monitor the progress of the TWC
diagnostic.  To complete the TWC diagnostic with a good
catalyst, the counter must be allowed to increment to 49
samples and roll over to 0 at least twice.

DTC P0430 – TWC System Low Efficiency Bank 2

 

Step

Action

Value(s)

Yes

No

1

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

Go to 

Step 2

Go to 

OBD

System

Check

2

Are any other DTCs set (such as P0160)?

Diagnose

other DTC(s)

first

Go to 

Step 3

3

1. Visually and physically inspect the three-way

catalytic converter for damage.  Check for the
following:

D

dents

D

severe discoloration caused by excessive
temperatures

D

holes

D

internal rattle caused by damaged catalyst

2. Also, ensure that the three-way catalytic converter

is a proper original equipment manufacturer part.

Did your inspection reveal a problem?

Go to 

Step 6

Go to 

Step 4

4

1. Visually and physically inspect the exhaust system

between the three-way catalytic converter and the
rear converter flange for leaks, damage, and loose
or missing hardware.

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

Did your inspection reveal a problem?

Go to 

Step 7

to verify

repair

Go to 

Step 5

6E–295

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0430 – TWC System Low Efficiency Bank 2

  (Cont'd)

Step

No

Yes

Value(s)

Action

5

1. Visually and physically inspect the Bank 2 HO2S 2.
2. Ensure that the Bank 2 HO2S 2 is secure and that

the pigtail and wiring harness is not contacting the
exhaust pipe or is not otherwise damaged.

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

Did your inspection reveal a problem?

Go to 

Step 7

to verify

repair 

Go to 

Step 6

6

Replace the three-way catalytic converter.

NOTE: Check for conditions which may cause catalyst
damage (refer to 

Diagnostic Aids).

Is the action complete?

Go to 

Step 7

to verify

repair

7

1. Review and record the Tech 2 Failure Records data.
2. Clear DTC P0430.
3. Start the engine and allow it to warm up until the

engine coolant temperature monitored on the Tech
2 is above the specified value.

4. Run the engine to maintain the specified mass air

flow range for at least 6 minutes.

5. Operate the vehicle to maintain DTC P0430 test

conditions (refer to 

DTC Test Description in

Diagnostic Support for detailed instructions).

6. Using a Tech 2, monitor “DTC” info for DTC P0430

until the DTC P0430 test runs.

7. Note the test result.

Does the Tech 2 indicate DTC P0430 passed this
ignition?

Engine

coolant temp:

greater than

70

°

C

(158

°

F).

Mass air flow:

between 2.5

g/second and

10 g/second

Complete

repair.  If a
driveability

symptom still

exists, refer

to 

Symptoms.

Check the

Procedure

Refer to

Diagnostic

Aids

6E–296

6VE1 3.5 ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P0444 EVAP Purge Control Circuit Open

D06R200089

Circuit Description

The canister purge solenoid valve is controlled by the
Power Train Control Module (PCM).The PCM monitors
vacuum level via the fuel tank pressure sensor input.
At an appropriate time, the EVAP canister purge solenoid
is “ON,” allowing engine vacuum to draw a small vacuum
on the entire evaporative emissions system.

Conditions for setting the DTC

D

The Ignition is “ON”.

D

Engine is running.

D

System voltage is between 11.5 volts and 16 volts.

Action Taken When the DTC Sets

D

The PCM will ON the MIL after second trip with
detected the fault.

D

The PCM will store conditions which were present
when the DTC set as Freeze Frame and in the Failure
Records data.

Conditions for Clearing the MIL/DTC

D

The PCM will turn the MIL “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

D

A history DTC P0444 will clear after 40 consecutive trip
cycles during which the warm up cycles have occurred
without a fault.

D

DTC P0444 can be cleared using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

An intermittent may be caused by the following:

D

Poor connections.

D

Mis routed harness.

D

Rubbed through wire insulation.

D

Broken wire inside the insulation.

Check for the following conditions:

D

Poor connection at PCM-Inspect harness connectors
for backed out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal to wire connection.

D

Damaged harness-Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
EVAP purge solenoid display on the Tech 2 while
moving connectors and wiring harnesses related to the
sensor.
A change in the display will indicate the location of
the fault. If DTC P0444 cannot be duplicated, the
information included in the Failure Records data can
be useful in determined vehicle mileage since the
DTC was last set.

If it is determined that the DTC occurs intermittently,
performing the DTC P0444 Diagnostic Chart may
isolate the cause of the fault.

6E–297

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0444  EVAP Purge Control  Circuit Open

 

Step

Action

Value(s)

Yes

No

1

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

Go to 

Step 2

Go to 

OBD

System

Check

2

1. Install the Tech 2.
2. Ignition is “ON”,
3. Engine is “ON” and operate the accelerator pedal

for 3 or 4 times.

4. Observe the EVAP purge solenoid reading on the

Tech 2.

Is the EVAP purge solenoid reading near the specified
value?

More than 1%

Check the

Procedure

Refer to

Diagnostic

Aids

Go to 

Step 3

3

Check the power supply circuit.

1. Ignition is “OFF”.
2. Disconnect the canister purge solenoid valve.
3. Ignition is “ON”.
4. Using a DVM, measure at the EVAP purge solenoid

connector between ground and voltage supply.

Was the measurement near the specified value?

Battery

voltage

Go to 

Step 4

Go to 

Step 5

4

Check the signal circuit for the EVAP purge solenoid.

1. Ignition is “OFF”.
2. Disconnect the canister purge solenoid valve.
3. Disconnect the PCM.
4. Check the circuit between EVAP purge solenoid

connector and PCM connector.

Is the problem found?

Go to 

Step 5

Go to 

Step 6

5

Repair the circuit as necessary.

Is the action complete?

Verify repair

6

Check the canister purge solenoid valve. Using a DVM,
measure resistance for purge solenoid valve connector
terminal.

Is the purge solenoid valve resistance within the
specified values?

25–30 

W

 (at

68

°

F{20

°

C})

Go to 

Step 8

Go to 

Step 7

7

Replace the canister purge solenoid valve.

Is the action complete?

Verify repair

8

Replace the

IMPORTANT: The replacement PCM must be
programmed. 

Refer to 

ON-Vehicle Service in Power Control Module

and Sensors for procedures.

And also refer to latest Service Bulletin. Check to see
if the latest software is released or not.

And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.

Is the action complete?

Verify repair

 

 

 

 

 

 

 

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