Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1469

6E2–327

RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0445 EVAP Purge Control Circuit Short

 

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. Observe the EVAP purge solenoid reading on the

Tech 2.

Is the EVAP purge solenoid reading near the specified
value?

0%

Refer to

Diagnostic

Aids

Go to 

Step 3

3

Check the signal circuit for canister purge solenoid
valve.

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 4

Go to 

Step 5

4

Repair the circuit as necessary. Is the action complete?

—

Verify repair

—

5

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 (at

68

°

F{20

°

C})

Go to 

Step 7

Go to 

Step 6

6

Replace the canister purge solenoid valve.

Is the action complete?

—

Verify repair

—

7

Replace the PCM.

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

—

6E2–328

RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) 

P0446 EVAP Canister Vent Control Malfunction

060RY00398

Circuit Description

The evaporative system includes the following
components:

D

Fuel tank

D

EVAP canister vent solenoid

D

Fuel tank (vapor) pressure sensor

D

Fuel pipes and hoses

D

Vapor lines

D

Fuel cap

D

Evaporative emissions canister

D

Purge lines

D

EVAP canister purge solenoid

An incorrect fuel tank pressure sensor signal is detected
by monitoring fuel tank pressure when the key is first
turned “ON” during a cold start.  If the fuel tank pressure
signal is out of range, DTC P0446 will set. A restricted or
blocked EVAP vent path is detected by monitoring fuel
tank pressure during normal operation (EVAP canister
vent solenoid open, EVAP canister purge solenoid
normal).  With the EVAP canister vent solenoid open,
vacuum level in the system should be very low unless the
vent path is blocked.  A blockage can be caused by the
following condition:

D

Faulty EVAP canister vent solenoid (stuck closed).

D

Plugged, kinked or pinched vent hose.

D

Shorted EVAP canister vent solenoid driver circuit.

D

Plugged evaporative canister.

If any of these conditions are present, DTC P0446 will set.

Conditions for Setting the DTC

D

No TP sensor, ECT sensor, Tank pressure sensor, IAT
sensor, or MAP sensor DTCs set.

D

Start-up engine coolant temperature and start-up
intake air temperature are more than 4

°

C (39

°

F) but

less than 34

°

C(93

°

F).

D

Start-up engine coolant temperature is not more than
7

°

C (13

°

F) greater than start-up intake air

temperature.

D

Fuel tank level is between 15% and 85%.

D

BARO is greater than 70 kPa.

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 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 P0446 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

6E2–329

RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

D

DTC P0446 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 to the
EVAP canister vent solenoid, EVAP canister purge
solenoid and the fuel tank pressure sensor for an
intermittent open or short circuit.

D

Kinked, pinched, or plugged vent hose–Verify that the
vent hose between the EVAP canister and EVAP
canister vent solenoid is not restricted.
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.
2. If a vent solenoid electrical fault is present, the purge

system will not operate correctly.  Repairing the
electrical fault will very likely correct the condition
that set DTC P0446.

3. Checks the fuel tank pressure sensor at ambient

pressure.

4. Verifies that the fuel tank pressure sensor accurately

reacts to EVAP system pressure changes.

6. Checks for a blocked EVAP canister.

DTC P0446– EVAP Canister Vent Control Malfunction

 

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.”
2. Capture Failure Records data for DTC P0446 and

clear DTCs.

3. Ignition “OFF.”
4. Remove the fuel cap.
5. Ignition “ON.”
6. Observe “Fuel Tank Pressure” on the Tech 2.

Does Tech 2 indicate “Fuel Tank Pressure” at the
specified value?

1.51V

Go to 

Step 3

Go to 

Fuel

Tank

Pressure

System

3

IMPORTANT: Before continuing with diagnosis, zero
the EVAP pressure and vacuum gauges on the EVAP
pressure/purge cart J 41413 (refer to tool operating
instructions).

7. Replace the fuel cap.
8. Using the Tech 2, command the EVAP vent

solenoid “ON” (closed).

9. Connect the EVAP pressure/purge cart J 41413 to

the EVAP service port.

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

pressurize the EVAP system to the specified value.

11. Observe “Fuel Tank Pressure” on the Tech 2.

Does Tech 2 indicate “Fuel Tank Pressure” at the
specified value?

1.52 – 1.69V

Go to 

Step 4

Go to 

Fuel

Tank

Pressure

System

4

1. Maintain the EVAP pressure at 5 in. at H

2

O.

2. Using Tech 2, command the EVAP vent solenoid

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

Does the EVAP pressure return to the specified value
within 30 seconds?

0 in. H

2

O

Refer to

Diagnostic

Aids

Go to 

Step 5

6E2–330

RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0446– EVAP Canister Vent Control Malfunction

  (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. H

2

O

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.
H

2

O.

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 30 seconds?

0 in. H

2

O

Verify repair

Go to 

Step 2