Isuzu 1999 RODEO Workshop Manual page 1567

6E2–324
RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS
Any of the above conditions can set DTC P0440.
Conditions for Setting the DTC
f No TP sensor, ODM, IAT sensor, or MAP sensor DTCs
set.
f Start-up engine coolant temperature is less than 32°C
(90°F).
f Start-up engine coolant temperature is not more than
7°C (13°F) greater
temperature.
f Start-up intake air temperature is greater than 4°C
(39°F) .
f Start-up intake air temperature is not more than 2°C
(4°F) greater than
temperature.
f Vehicle speed is less than 75 mph (120 km/h).
f Throttle position is greater than 7% but less than 30%.
f Minimal fuel slosh.
f Fuel tank level is between 15% and 85%.
f BARO is greater than 75 kPa.
f The EVAP system is unable to achieve or maintain
vacuum during the diagnostic test.
f Above conditions are present for 60 to 180 seconds.
Action Taken When the DTC Sets
f The PCM will illuminate the MIL during the second key
cycle in which the DTC sets.
f 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
f The PCM will turn the MIL "OFF" when the diagnostic
has been run and the fault condition is no longer
present.
f A history DTC P0440 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
f DTC P0440 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 or disconnected source vacuum line, EVAP
purge line, 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.
f Kinked, pinched, or plugged vacuum source, EVAP
purge, or fuel tank vapor line–Verify that the lines are
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.
than start-up intake
start-up engine coolant
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 P0440.
air
3. Checks the fuel tank pressure sensor at ambient
pressure.
4. Determines whether or not the EVAP system can be
sealed sufficiently to be pressurized. If not, the
large leak must be located and corrected before
continuing with diagnosis.
5. Verifies that the fuel tank pressure sensor accurately
reacts to EVAP system pressure changes.
8. Checks for a blocked EVAP canister purge solenoid.
The PCM commands the EVAP canister purge
solenoid "OFF" (open) and the vent solenoid "ON"
(closed) with the Tech 2 "System Perf." EVAP
output control function activated. Any pressure in
the system should be released through the EVAP
canister purge solenoid within a few seconds when
"System Perf." is activated.
9. Ensures that sufficient source vacuum is present at
the EVAP canister purge solenoid.