Inspection Procedure
Tools Required
J 41413 EVAP Pressure/Purge
Diagnostic Station
Whenever the DTC diagnostics lead to a no trouble found or a purge solenoid
valve replacement, proceed with the following charcoal canister diagnostics.
Notice: Use the EVAP Pressure/Purge Diagnostic Station J 41413 in order
to provide a clean, dry, low pressure gas source. Do not substitute any other
pressurized gas source. Damage may result to the EVAP system.
The EVAP Pressure/Purge Diagnostic Station is required to provide a
clean, dry, low pressure gas source. Do not substitute any other pressurized
gas source or damage to the EVAP system may result.
- Turn the ignition OFF.
- Remove the EVAP canister purge solenoid valve from the vehicle.
Refer to
Evaporative Emission Canister Purge Solenoid Valve Replacement
.
- Lightly tap the EVAP canister purge solenoid valve on a clean
work area.
- Look for carbon particles existing from either of the vacuum ports.
- If no carbon release is evident, reinstall the components. Continue
with the published service manual DTC procedures.
- If carbon is being released from either component, continue with
this service procedure.
- Remove the charcoal canister from the vehicle. Refer to
Evaporative Emission Canister Replacement
.
- Turn off the main cylinder valve (1) on the EVAP Purge/Pressure
Diagnostic Station.
- Disconnect the black hose (4) that connects the nitrogen cylinder
to the EVAP Purge/Pressure Diagnostic Station at the pressure regulator (5).
- Using a section of the vacuum hose, connect one end onto the open
fitting of the EVAP Purge/Pressure Diagnostic Station pressure regulator (5).
- Connect the other end of the vacuum line side of the EVAP purge
solenoid valve line at the vehicle.
- Turn on the main nitrogen cylinder valve (1).
- Continue to blow any debris from the purge line for 15 seconds.
- Return the EVAP Purge/Pressure Diagnostic Station to its original
condition by re-installing the black hose (4) disconnected in step 9.
- Replace the EVAP purge solenoid valve and the charcoal canister
with the new components.
- Connect the EVAP Purge/Pressure Diagnostic Station to the vehicle
EVAP service port. Turn the four position switch to Purge.
- Start the engine. Allow the engine to reach the operating temperature.
- Open the throttle until the engine speed reaches 2,000 RPM.
- Note the H2O vacuum gauge on the EVAP Purge/Pressure Diagnostic
Station. The vacuum should read greater than 15 in H2O.
- If the vacuum is less than 15 in H2O, perform a
complete throttle body service including a cleaning of the purge port(s) as
outlined in the service manual. Go to step 1.
- If the vacuum is greater than 15 in H2O, continue
with the published service manual diagnostics.