Isuzu 1999 RODEO Workshop Manual page 884

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 3 consecutive ignition
cycles in which the diagnostic runs without a fault.
f A history Diagnostic Trouble Code will clear after 40
consecutive warm up cycles without a fault.
f A Tech 2 can clear the Diagnostic Trouble Codes.
Diagnostic Aids
f A loose, missing, or damaged fuel cap.
f Missing or damaged O–rings at the fuel vapor fittings
and the EVAP purge line canister fittings.
f Cracked EVAP canister.
f Damaged source vacuum line, EVAP purge line, EVAP
vent hose or fuel 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 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 vent solenoid, the EVAP purge solenoid, and the
DTC P0442 EVAP Control System Small Leak Detected
Step
1 Was the "On–Board Diagnostic (OBD) System Check"
performed?
2 Is Diagnostic Trouble Code P0461, P0462, or P0463
also set?
3 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 vent solenoid click ON and
OFF?
4 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.)
5 Has the battery been disconnected?
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
Action
fuel tank pressure sensor for an intermittent open or
intermittent short circuit.
Check for charcoal particles. Refer to Carbon Particle
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 causes 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.
3. 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 P0442.
4. Checks the fuel tank pressure sensor at ambient
pressure.
6. Forces the fuel tank pressure sensor to re–zero.
7. Verifies that the fuel tank pressure sensor
accurately reacts to EVAP system pressure
changes.
Value(s)
— Go to Step 2
Applicable
— DTC Table
— Go to Step 4
1.51V Go to Step 7
Go to EVAP
— Diagnosis
6E1–257
Yes No
Go to
Powertrain
OBD System
Check
Go to
Go to Step 3
Go to PCM
Outputs
Diagnosis
Go to Step 5
Control
System
Go to Step 6