Isuzu Trooper (2000 year). Manual - part 302

6E–337

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0446– EVAP Canister Vent Blocked

  (Cont'd)

Step

No

Yes

Value(s)

Action

5

1. Disconnect the large vent hose (marked “AIR”) from

the EVAP canister.

2. Switch the rotary switch on the cart J 41413 to

“PURGE.”

3. Ignition “ON,” engine idling at normal operating

temperature.

4. Observe vacuum gauge for 5 seconds while holding

the engine speed at 2500 RPM.

Does the vacuum remain less than the specified value?

30 in. H2O

Go to 

Step 6

Go to 

Step 8

6

1. Inspect the vent hose between the EVAP canister

and the EVAP canister vent solenoid for kinks,
pinched areas, or any other form of blockage.

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

Was a problem found?

—

Go to 

Step 9

Go to 

Step 7

7

Replace the EVAP canister vent solenoid.

Is the action complete?

—

Go to 

Step 9

—

8

Replace the EVAP canister.

Is the action complete?

—

Go to 

Step 9

—

9

1. Using Tech 2, command the EVAP canister vent

solenoid “ON” (closed).

2. Using the EVAP pressure/purge cart J 41413,

pressurize and monitor the EVAP system to 15 in.
H2O.

3. Switch the rotary switch on cart J 41413 to “HOLD.”
4. Using the Tech 2, command the EVAP canister vent

solenoid “OFF” (open) while observing the EVAP
pressure gauge on cart J 41413.

Does the EVAP pressure return to the specified value
within 5 seconds?

0 in. H

2

O

Verify repair

Go to 

Step 2

6E–338

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P0452 Fuel Tank Pressure Sensor (Vapor Pressure Sensor) Low Voltage

D06RY00178

Circuit Description

The powertrain control module (PCM) monitors fuel tank
pressure sensor (Vapor pressure sensor) of the
Enhanced Evapo system. When the tank pressure output
indicates low voltage, PCM will set DTC P0452.

Conditions for Setting the DTC

D

Tank sensor output is less than 0.2 volts for 12.5 sec.

D

100 test failures within a 200 tests.

Action Taken When the DTC Sets

D

The PCM will illuminate the malfunction indicator lamp
(MIL) as soon as failure detected.

D

The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in 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 P0402 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

D

DTC P0404 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

Open circuit of 5 volt reference line – Inspect wiring
harness from PCM to the sensor. The PCM turns
P0452, and P0107 at the same time.

D

Open circuit or short circuit to ground line – Inspect
wiring harness from PCM to the sensor. The PCM turns
P0452 and P0107 at the same time.

D

Tank fuel pressure sensor malfunction may cause
P0452.

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.

6E–339

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0452 – Tank Pressure Sensor Low Voltage

 

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

1. Ignition “ON,” engine “OFF”, review and record

Tech 2 Failure Records Data.

2. Operate the vehicle within Failure Records

conditions as noted.

3. Using a Tech 2, monitor “DTC” info for DTC P0452

until the DTC P0452 test runs. Note the result.

Does the Tech 2 indicates DTC P0452 or P0452/P0107
failed this ignition?

—

P0452/P0107

turn on

Go to 

Step 3

P0452 turns on

Go to 

Step 6

Refer to

Diagnostic

Aids

3

1. Ignition “OFF”.
2. Disconnect connector at the PCM.
3. Ignition “ON”.
4. At the PCM connector, measure voltage with a DVM

at  F54 and S37 terminals.

Was the voltage in range of voltage?

4–6 V

Go to 

Step 4

Go to 

Step 10

4

1. Ignition “OFF”.
2. Connect the PCM connector to the PCM.
3. Backprobe with a DVM at fuel tank pressure sensor

between 5 V reference terminal and sensor ground
terminal.

Was the voltage within range?

4–6 V

For P0452 go

to 

Step 5 and

for P0107, go

to diagnosis

section.

Go to 

Step 5

5

1. Locate open wiring of 5 volt reference circuit from

the PCM to fuel tank pressure sensor.

2. Repair wiring harness.

Is the action complete?

—

Verify repair

—

6

1. Ignition “ON”
2. At the PCM connector, backprove with a DVM at the

sensor output for the voltage.

Was voltage within the range?

Less than

0.2 V

Go to 

Step 7

Go to 

Step 10

7

At the sensor output terminal, backprobe with a DVM at
the sensor output

Was voltage within the range?

Less than

0.2 V

Go to 

Step 9

Go to 

Step 8

8

1. Locate open circuit or short circuit to ground line.
2. Repair the harness.

Is the action complete?

—

Verify repair

—

9

1. Locate open circuit or short circuit to ground line.
2. Repair the harness.

Is the action complete?

—

Verify repair

—

6E–340

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0452 – Tank Pressure Sensor Low Voltage

  (Cont'd)

Step

No

Yes

Value(s)

Action

10

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed.  Refer to 

On-Vehicle Service in

Powertrain 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

—