Isuzu 1999 RODEO Workshop Manual page 892

DTC P0446 EVAP Control System Vent Control Circuit Malfunction
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? (if no, start with the diagnosis chart for other
sensors in the circuit and see if 5V returns.)
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?
5 Has the battery been disconnected?
6 Disconnect the battery, wait 30 seconds, then
reconnect the battery.
Is the action complete?
7 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. Pressurize the EVAP system to the specified value
using the EVAP pressure/purge cart J41413
(monitor the pressure using the gauge on the cart
with the switch in the "HOLD" position.
5. Observe the Fuel Tank Pressure on the Tech 2.
Is the Fuel Tank Pressure at the specified value?
8 1. Maintain the specified EVAP pressure.
2. Using the Tech 2, command the EVAP vent solenoid
OFF (open) while observing the EVAP pressure
gauge on the cart J41413.
Does the EVAP pressure return to the specified value
within 5 seconds?
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
Action Value(s) Yes
— Go to Step 2
Go to
Applicable
— DTC chart
– Go to Step 4
1.51V Go to Step 7
Go to EVAP
Control
System
—
Diagnosis
— Go to Step 4
1.52 – 1.69V Go to Step 8
Refer to
Diagnostic
0 in. H2O Aids
6E1–265
No
Go to
Powertrain
OBD System
Check
Go to Step 3
Go to PCM
Outputs
Diagnosis
Go to Step 5
Go to Step 6
—
Go to EVAP
Control
System
Diagnosis
Go to Step 9