Isuzu Rodeo UE. Manual - part 393

6E2–327

RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0440 – EVAP System 

  (Cont'd)

Step

No

Yes

Value(s)

Action

15

Replace the EVAP canister vent solenoid.

Is the action complete?

—

Go to 

Step 16

—

16

1. Ignition “ON,” engine not running.
2. Using the Tech 2, command the EVAP canister vent

solenoid “ON” (closed).

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

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

4. Switch the rotary switch on the cart to “HOLD” and

observe the EVAP pressure gauge.

Does the pressure decrease to less than the specified
value within 2 minutes?

2.14V

Go to 

Step 3

Verify repair

6E2–328

RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Diagnostic Trouble Code (DTC) P0442 EVAP System Small Leak Detected

D06RX019

Circuit Description

The evaporative system includes the following
components:

f

Fuel tank

f

EVAP canister vent solenoid

f

Fuel tank pressure sensor

f

Fuel pipes and hoses

f

Vapor lines

f

Fuel cap

f

Evaporative emissions canister

f

Purge lines

f

EVAP canister purge solenoid

The evaporative leak detection diagnostic strategy is
based on applying vacuum to the EVAP system and
monitoring vacuum decay.  The powertrain control
module (PCM) monitors vacuum level via the fuel tank
pressure sensor input. At an appropriate time, the EVAP
canister purge solenoid and the EVAP canister vent

solenoid are turned “ON,” allowing engine vacuum to
draw a small vacuum on the entire evaporative emissions
system.  After the desired vacuum level has been
achieved, the EVAP canister purge solenoid is turned
“OFF,” sealing the system.  A leak is detected by
monitoring for a decrease in vacuum level over a given
time period, all other variables remaining constant.  A
small leak in the system will cause DTC P0442 to be set.

Conditions for Setting the DTC

f

No TP sensor, ODM, IAT sensor, or MAP sensor DTCs
set.

f

The DTC P0440 diagnostic test has passed.

f

A vacuum decay condition, indicating a small leak, is
detected during the diagnostic test.

6E2–329

RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Action Taken When the DTC Sets

f

The PCM will illuminate the malfunction indicator lamp
(MIL) during the second key cycle in which the DTC
sets.

f

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

Conditions for Clearing the MIL/DTC

f

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.

f

A history DTC P0442 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

f

DTC P0442 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:

f

Cracked or punctured EVAP canister.

f

Damaged source vacuum line, EVAP purge line, EVAP
vent hose or fuel tank vapor line.

f

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.

f

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. 

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 an EVAP canister vent solenoid or an EVAP

canister purge 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 P0442.

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.

6E2–330

RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

DTC P0442 – EVAP System Leak Detected

 

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

Does the 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 EVAP
pressure/purge cart J 41413 (refer to tool operating
instructions).

1. Replace the fuel cap.
2. Capture Failure Records data for DTC P0442 and

clear DTCs.

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

the EVAP service port.

4. Using the Tech 2, command the EVAP canister vent

solenoid “ON” (closed).

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

pressurize the EVAP system to the specified value.

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

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

1.52 – 1.67V

Go to 

Step 4

Go to 

Fuel

Tank

Pressure

System

4

1. Ignition “ON,” engine idling.
2. Using the Tech 2, command the EVAP canister vent

solenoid “ON” (closed).

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

pressurize the EVAP system to 15 in. H2O.

4. Switch the rotary switch on the cart to “HOLD” and

observe the EVAP pressure gauge.

Does the pressure decrease to less than the specified
value within 2 minutes?

10 in. H2O

Go to 

Step 5

Refer to

Diagnostic

Aids

5

1. Disconnect the fuel tank vapor line and the EVAP

purge line from the EVAP canister.

2. Block the canister fitting for the fuel tank vapor line.
3. Connect a hand vacuum pump to the canister fitting

for the EVAP purge line.

4. Ensure that the EVAP canister vent solenoid is still

commanded “ON” (closed).

5. Attempt to apply vacuum to the EVAP canister.

Can the vacuum be maintained at the specific value?

5 in. Hg

Go to 

Step 8

Go to 

Step 6

6

1. Visually/physically check for the following

conditions:

f

Vent hose disconnected or damaged.

f

EVAP canister damaged.

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

Was a problem found?

—

Go to 

Step 10

Go to 

Step 7