Isuzu Rodeo UE. Service manual - part 220

6E1–251

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0440 EVAPORATIVE EMISSION (EVAP)

CONTROL SYSTEM MALFUNCTION

D06RX056

Circuit Description

The evaporative system includes the following
components:

f

Fuel tank

f

EVAP vent solenoid

f

Fuel tank pressure sensor

f

Fuel pipes and hoses

f

Fuel vapor lines

f

Fuel cap

f

EVAP canister

f

Purge lines

f

EVAP canister purge valve

f

EVAP service port

The evaporative emission system is checked by applying
vacuum to the EVAP system and monitoring for a vacuum
decay.  The PCM monitors the vacuum level through the
fuel tank pressure sensor signal.
At an appropriate time, the EVAP canister purge valve
and the EVAP vent solenoid are turned ON, allowing the
engine to draw a small vacuum on the entire evaporative
emission system. After the desired vacuum level has
been achieved, the EVAP canister purge valve is turned
OFF, sealing the system. If a sufficient vacuum level
cannot be achieved, a large leak is indicated. This can be
caused by the following conditions:

f

Missing or faulty fuel cap

f

Disconnected or faulty fuel tank pressure sensor

f

Disconnected, damaged, pinched, or blocked fuel tank
vapor line

f

Disconnected or faulty EVAP canister purge valve

f

Disconnected or faulty EVAP vent solenoid

f

Open ignition feed circuit to the EVAP vent or purge
solenoid

f

Damaged EVAP canister

f

Leaking fuel sender assembly O–ring

f

Leaking fuel tank or fuel filler neck

Any of the above conditions can set a Diagnostic Trouble
Code P0440. DTC P0440 is a type A code.

Conditions for Setting the DTC

f

Diagnostic Trouble Codes P0106, P0107, P0108,
P0112, P0113, P0117, P0118, P0121, P0122, P0123,
P0125, P0131, P0132, P0133, P0134 and P1133 not
set.

f

The BARO is greater than 72.3 kPa.

f

IAT and ECT are between 3.5

°

C (38.5

°

F) and 90.5

°

F

at engine start up.

f

The difference between IAT and ECT at start up is less
than 6.75

°

C (12.2

°

F).

f

The Vehicle Speed is less than 98 km/h (60 mph).

f

The Fuel Tank Level Sensor reads between 10% and
90%.

f

Fuel Level counts vary by less than 15 counts in a
0.125 second time frame.

f

Maximum Engine Run time is at least 540 seconds.

6E1–252

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

f

The difference between the actual Fuel Tank Pressure
and the expected Fuel Tank Pressure is less than the
PCM’s expectations.

The above conditions are met, and the following condition
is met once:

f

The EVAP system is unable to achieve or maintain
vacuum during the diagnostic test.  The amount of
decay will vary with the fuel level.

Action Taken When the DTC Sets

f

The Malfunction Indicator Lamp (MIL) will illuminate.

f

The PCM will disable the EVAP purge vale solenoid.

f

The PCM will record operating conditions at the time
the diagnostic fails.  The Freeze Frame and Failure
Records buffers will store this information.

f

A history Diagnostic Trouble Code is stored.

Conditions for Clearing the MIL/DTC

f

The MIL will turn OFF after one ignition cycle in which
the diagnostic runs without a fault.

f

Freeze Frame information and the history Diagnostic
Trouble Code will clear after one ignition cycle in which
the diagnostic runs without a fault.

f

Diagnostic Trouble Codes can be cleared with the
Scan Tool’s ”Clear Info” function.

Diagnostic Aids

Check for the following conditions:

f

A missing, loose, or damaged fuel cap.

f

Missing or damaged O–rings at the EVAP canister fuel
vapor fittings and the purge line fittings.

f

A cracked EVAP canister.

f

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

f

The Fuel Pressure Sensor shares a 5 Volt reference
with the MAP sensor and TP sensor.

If these codes are also set, it could indicate a
problem with the 5 Volt reference circuit or
components itself.

f

The Fuel Pressure Sensor share a ground with the
MAP sensor and the TP sensor.

f

A poor connection at the PCM: Inspect the harness
connectors for backed out terminals, improper mating,
broken locks, improperly formed or damaged
terminals.

f

Damaged harness: Inspect the wiring harness to the
EVAP vent solenoid, the EVAP purge solenoid, and the
fuel tank pressure sensor for shorts to ground, shorts
to battery positive and open circuits.

f

A kinked, pinched or plugged vacuum source, EVAP
purge, or fuel tank vapor line.  Verify that the lines are
not restricted.

Check for charcoal particles.  Refer to Carbon Particles
Removal from EVAP System before starting repairs.
Reviewing the Fail Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the Diagnostic Trouble Code to
set occurs. This may assist in diagnosing the condition.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart:
1. The Powertrain OBD System Check prompts the

technician to complete some basic checks and store
the freeze frame and failure records data on the
Tech 2 if applicable.  This creates an electronic copy
of the data taken when the malfunction occurred.
The information is then stored on the Tech 2 for
later reference.

4.  If a vent solenoid or EVAP canister purge valve

electrical malfunction is present, the purge system
will not operate correctly.  Repairing the electrical
malfunction will very likely correct the condition that
set Diagnostic Trouble Code P0440.

5.  Check the fuel tank pressure sensor at ambient

pressure.

7.  Forces the fuel tank pressure sensor to re–zero.

8. Determines whether or not the EVAP system is

sealed sufficiently to be pressurized.  If not, the
large leak must be located and corrected before
continuing with diagnosis.

9. Verifies that the fuel tank pressure sensor

accurately reacts to EVAP system pressure
changes.

12. Ensures that sufficient source vacuum is present at

the EVAP canister purge valve.

13. Check for a stuck closed EVAP canister purge

valve.

20. Insures proper system integrity.

6E1–253

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0440 EVAP Control System Malfunction

 

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On–Board Diagnostic (OBD)
System Check performed?

—

Go to Step  2 

Go to

Powertrain

OBD System

Check 

2

Is Diagnostic Trouble Code P0461, P0462 or P0463
also set?

—

Go to

Applicable

DTC Chart

Go to Step  3 

3

1. Visually/Physically check the fuel cap for missing or

loose conditions.

2. Replace or tighten the fuel cap is necessary.

Was a loose or missing fuel cap found?

—

Go to Step

20 

  Go to Step

4 

4

1. Install a Tech 2.
2. Command the EVAP canister purge valve and vent

solenoid ON and OFF with the Tech 2.

Does the purge valve and sent solenoid click when
commanded ON and OFF?

—

Go to Step  5 

Go to PCM

Outputs

Diagnosis

5

1. Turn the ignition switch OFF.
2. Remove the fuel cap.
3. Turn the ignition switch ON.

Is the Fuel Tank Pressure at the specified value? (if no,
start with the diagnosis chart for other sensors in the
circuit and see if 5V returns.)

1.51V

Go to Step  8 

Go to Step  6 

6

Has the battery been disconnected?

—

Go to EVAP

Control

System

Diagnosis 

Go to Step  7 

7

Disconnect the battery, wait 20 seconds then
reconnect the battery.

Is the action complete?

—

Go to Step  5 

—

8

IMPORTANT: Before continuing with this diagnosis,
zero the EVAP Pressure and Vacuum gauges on the
EVAP pressure/purge cart J41413.  Also, read the
temperature variation instruction card.  (refer to tool
operating instructions).

1. Reinstall the fuel cap.
2. Using the Tech 2, command the EVAP vent solenoid

ON (closed).

3. Connect the EVAP pressure/purge cart J41413 to

the EVAP service port.

4. Attempt to pressurize the EVAP system to the

specified value using the EVAP pressure/purge cart
J41413 (monitor the pressure using the gauges on
the cart with the switch in the HOLD position).

Can the specified value be achieved?

5 in. H2O

Go to Step  9 

Go to Step

10 

9

1. Maintain the fuel tank pressure at the specified

value?

2. Observe the Fuel Tank Pressure on the Tech 2.

Is the Fuel Tank Pressure at the specified value?

1.47

∼

1.51V

Go to Step

12 

Go to Step

11 

6E1–254

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0440 EVAP Control System Malfunction

  (Cont'd)

Step

No

Yes

Value(s)

Action

10

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 vent solenoid is still

commanded ON (closed).

5. Attempt to apply the specified vacuum to the EVAP

canister.

Can vacuum be maintained at the specified value?

5 in. Hg   (17

kPa)

Go to Step

15 

Go to Step

14 

11

1. Visually/physically check for the following

conditions:

f

Restricted fuel tank vapor line.

f

Restricted EVAP purge line.

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

Was a problem found?

—

Go to Step

20 

Go to EVAP

Control

System

Diagnosis 

12

1. Disconnect the throttle body to EVAP emission

canister purge vale vacuum hose from the EVAP
canister purge valve.

2. Connect a hand vacuum pump to the EVAP canister

purge vale vacuum source fitting.

3. Apply the specified amount of vacuum to the EVAP

canister purge valve.

4. Command the EVAP purge valve ON, using the

Tech 2.

Does the EVAP canister purge vale release the
vacuum?

10in. of Hg

(34 kPa)

Go to Step

13 

Go to Step

17 

13

1. Connect the in. Hg vacuum gauge on the EVAP

pressure/purge cart J41413 of the vacuum source
line.

2. Start the engine.
3. Stabilize the engine rpm near the specified value.
4. Momentarily depress the throttle open and then

immediately let the throttle return to idle.

Did the vacuum gauge read greater than the specified
value when the throttle was opened then closed?

2500 RPM 10

in. Hg

Go to

Diagnostic

Aids 

Go to Step

18 

14

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 repair necessary?

—

Go to Step

20 

Go to Step

19 

15

1. Visually/physically check for the following

conditions:

f

Missing or malfunctioning fuel cap.

f

Disconnected or leaking fuel tank vapor line.

f

Disconnected or damaged EVAP purge line.

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

Was a repair necessary?

—

Go to Step

20 

Go to Step

16