p0441

[whitefirebird96]

I have researched it on the board and know what the code means. I even replaced the line going from the throttle body to the solenoid with a rubber hose. The line I took off showed no signs of a crack or anything. I know I should try a new gas cap next, but whenever I take off the cap to fill the car, I hear air pressure adjusting( a whoooshing sound) and figured that my cap was keeping pressure.

Can anyone explain how this code affects the running of the car? Anyone know a next step before taking it to a dealership and preparing for the outrageous fees?

[David8399]

Re: p0441

Circuit Description
The EVAP purge valve allows manifold vacuum to purge the canister. The Powertrain Control Module (PCM) supplies a ground to energize the EVAP purge valve (purge ON). The EVAP purge valve control is Pulse Width Modulated (PWM) or turned ON and OFF several times a second. The duty cycle (pulse width) is determined by engine operating conditions including load, throttle position, coolant temperature and ambient temperature. The duty cycle is calculated by the PCM and the output is commanded when the appropriate conditions have been met:

Engine coolant temperature above 25°C (77°F).
After the engine has been running about 2 1/2 minutes on a cold start or 30 seconds on a warm start.
The vehicle is operating in closed loop fuel control.
Canister purge commanded duty cycle varies according to operating conditions determined by mass air flow, fuel trim, and. intake air temperature.

Canister purge operation is also affected by throttle position.

VIN 1 -- Canister purge will be disabled if TP angle increases to above 33%. Canister purge will be re-enabled when TP angle decreases below 29%.
VIN K -- Canister purge will be disabled if TP angle increases to above 70%. Canister purge will be re-enabled when TP angle decreases below 66%.
The EVAP vacuum switch is a normally closed switch positioned in the purge line between the canister and the EVAP purge valve. The EVAP vacuum switch will open when vacuum increases to greater than 5 inches of water in the purge line. The PCM monitors the EVAP purge vacuum switch signal to determine of the evaporative emission control system is working properly. If the switch is closed (no purge flow) when the PCM is commanding the EVAP purge valve ON, DTC P0441 will be set.

Conditions for Setting the DTC
No EVAP Vacuum Switch, TP sensor, IAT sensor, Idle Speed, MAP sensor, ECT sensor, or MAF sensor DTCs set.
BARO reading is greater than 73 kPa.
Engine Coolant Temperature is less than 114°C (237°F).
Intake Air Temperature (IAT) sensor indicates an ambient temperature less than 70°C (158°F).
The difference between ECT and IAT is less than 10°C (18°F).
Engine speed is between 650 RPM and 5,000 RPM.
TP Sensor Indicates throttle position between 3-52 percent.
Canister purge PWM is greater than 75 percent.
EVAP vacuum switch remains closed (12 volts signal at the PCM).
Above conditions for longer than 4 seconds.
Action Taken When the DTC Sets
The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
Conditions for Clearing the MIL/DTC
The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
The DTC can be cleared by using the scan tool.
Diagnostic Aids
Check for the following conditions:

• Poor connection at the PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.

• Damaged harness. Inspect the wiring harness for damage.

• If the harness appears to be OK, observe the EVAP vacuum switch display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display will indicate the location of the fault.

• Faulty or damaged canister. A faulty canister may intermittenly allow charcoal into the EVAP purge solenoid, vacuum switch, and associated lines causing a DTC to be set. Use the following procedure to check for a carbon release condition:

Turn OFF the ignition switch.
Remove the EVAP purge solenoid. Refer to Evaporative Emission (EVAP) Canister Purge Solenoid .
Remove the EVAP vacuum switch. Refer to Evaporative Emission (EVAP) Vacuum Switch .
Lightly tap the purge solenoid and (if applicable) the vacuum switch on a clean work area looking for carbon particles exiting either of the vacuum ports.
If no carbon release is evident, reinstall the components and continue with the DTC P0441 diagnostic table. If carbon is being released from either component, continue with this service procedure.
Remove the charcoal canister from the vehicle.
Ensure that the main cylinder valve is turned off on the J 41413 EVAP purge/pressure diagnostic station.
Disconnect the black hose that connects the nitrogen cylinder to the EVAP purge/pressure diagnostic station at the pressure regulator by unscrewing the knurled nut on the regulator. No tools are required to remove the black hose from the regulator.
Using a section of vacuum line, connect one end over the open threaded fitting of the EVAP purge/pressure diagnostic station pressure regulator.
Connect the remaining end to the purge solenoid end of the EVAP purge line at the vehicle and turn on the main nitrogen cylinder valve. Continue to blow any debris from the purge line for 15 seconds.
Return the EVAP Pressure/Purge Diagnostic Station to its original condition by re-installing the black hose that was disconnected in step 8.
Replace the following components:
• The EVAP purge solenoid. Refer to Evaporative Emission (EVAP) Canister Purge Solenoid .

• The EVAP canister. Refer to Evaporative Emission (EVAP) Canister Replacement .

• The EVAP vacuum switch. Refer to Evaporative Emission (EVAP) Vacuum Switch .

Proceed with the DTC P0441 diagnostic table.
Reviewing the Fail 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.

[David8399]

Re: p0441

this is the stuff the tech atthe dealer would be looking at when they figure it out. it is all from the gm book.

[whitefirebird96]

Re: p0441

that is great, this will give me a lot to play with before my dealership appointment in two weeks. Hopefully i get it figured out, the dealership said the last similar job ran about $500.

[kest874]

Re: p0441

I have the same issue that your having. Let me know what you come across.

I checked all connections and they appear to be tight. I pressure tested the plastic lines and they all hold pressure.

Anyone know where the the canister is?

[David8399]

Re: p0441

Anyone know where the the canister is?

it is behind the driver rear tire. mine fell off a little over a month ago havent put it back on yet, hasnt thrown any codes but i can smell fuel vapors sometimes.

[whitefirebird96]

Re: p0441

Couldn't resolve myself, so took it to the dealership. It turned out to be the EVAP purge solenoid. Part was 31.35 and part # is 1997210.

[spydercam]

Re: p0441

Anyone know where the purge solenoid is or what it looks like? I am having this issue too.

[spydercam]

Re: p0441

This is on the 3.4, I have the 3.8 but there is a part that looks similar to this, I guess that is it right?

Is this a simple install?

[ssms5411]

Re: p0441

Or you could disconnect it all and have someone delete it from the PCM, it makes for alot of more room on the pass. side valve cover.

[Mr. Logger]

Re: p0441

This is on the 3.4, I have the 3.8 but there is a part that looks similar to this, I guess that is it right?

Is this a simple install?

I think that is it. That part is located behind the alternator and slides on/off a bracket above the valve cover.

[ssms5411]

Re: p0441

There are 2 pieces on the passenger side for the 3.8, and there is also the canister in the driver side rear tire well.

[spydercam]

Re: p0441

Thanks guys I'll check it out.