Code P0449 On Chevy And Pontiac

Problem with my 2000 PONTIAC GRAND AM GT code P0449. Why does my car HAVE A CHECK ENGINE LIGHT on. IT IS FOR P0449. I CHECKED THE VENT SOLENOID AND IT IS TURNING ON AND OFF. COULD THE SOLENOID STILL BE BAD? WHAT ELSE SHOULD I DO? THANK YOU.

Answer:
If the vent valve is functioning, it is POSSIBLE that the solenoid in the valve is functioning, but the resistance is either too high or too low, and the PCM sees that and sets the code. If you do not have any leak codes along with it, then i would say to check the resistance of the wires between the pcm and the solenoid.

No more than .2 ohm on each. Make sure not grounded, and not shorted together. If the wiring all checks out, then i would replace the solenoid and clear codes. Also, be sure you are checking the vent valve, and not the Purge valve. Purge valve is on the engine, vent is under the rear of the car.

pontiac grand am

 

1998 Pontiac grand am v6 4 door v6.
Question: For some reason I can't get my emissions done because when they plug in the machine it won't work they get nothing.

We have checked all fuses under Hood and the inside fuses and they are fine,what can I do help!

Answer:
The emissions station is basically plugging in a scan tool, similar to what a mechanics would plug in to check for codes. If the scan tool cannot communicate with the car computer, and the fuses are all good, then you either have a bad computer or the wire used to communicate to the car computer has a break in it. Turn the key to the ON position and see if the check engine light comes on, if it does not, then most likely the computer is bad. If it does come on, that communication wire is going to need to be checked.


2002 Chevy Silverado 2500HD. Service Engine Soon. Codes: EVAP input low. I Replaced purge solenoid assembly. Low input to evap could the canister be bad or ?

Answer:
There are many components to the EVAP system on your Silverado. A low input code refers to voltage levels at a sensor. The canister itself has no electronic sensors so it most likely is not bad. A general check of components should be done to check for system leaks to start. A good sealing gas cap, preferably factory, is necessary as well. If you've changed the Purge Solenoid up near the top of the intake manifold, you should check the Vent Valve underneath the truck located at the rear of the gas tank.

There is an updated design from GM for your vehicle. Wiring and connectors should be checked for corrosion and wear. There is possibly an updated PCM software calibration that needs to be done as well.


Question: are there software calibrations needed on any other makes or models specifically my 2004 grand am with a 3.4 v6 what do you mean by updated design? For the vent valve or the evap system over all or ??

There are no updated software for this problem, but there may be for others. The only way to tell is to have the car hooked up to dealer terminal and compare software versions with what is in your cars modules, and what / if any updates are listed in terminal. On the Silverado, the valve was changed to prevent it from getting dirt inside and causing it to fail. The above is specific to this body style truck only on Chevy and GMC.


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