Hello Forum,
Had a layer of undercoating applied to the bottom of my 2000 Maxima GLE, and since then, the OBD scanner is pulling codes: P1490 and P0446. Entire car was also painted, will post pictures in a different post later.

Researched both codes like crazy, yet still not sure how to resolve them. The P1490 points to the Vacuum Cut Valve Bypass Valve. Can't pin point where that valve is exactly on a 2000 Maxima. Some posts showed it being in the bottom rear. Not sure which side.

Grateful if anyone has a descriptive picture of what I should be looking for, and where exactly it's located. And if anyone had a similar code, how they were able to clear it.

 

The Vacuum Cut valve bypass is part of the EVAP system. Honestly, I'm not sure where it is located on the DE-K, Maybe someone can chime in about that. The second code is also EVAP related it's the Evaporative Emmission Control System Vent Control Circuit. That's going to be near the Vacuum cut valve. Seems to me that your entire EVAP system is messed up.

The engine will operate 100% without either of these devices working. In fact they don't even have to be kept on the engine. However, if you remove them, you'll always have a check engine light. I've long since removed mine to clear clutter out of my engine bay, but I also don't have to worry about emissions. If you have to pass emissions you'll need to get them replaced.

 

the vacuum cut valve is a small cluster near the evap canister. #20

 

Many thanks for the replies, very much appreciated.

That diagram definitely helps, but would the "vacuum cut valve" be in the back of the car. Seems like it would be in the middle of the rear?

Usually with those codes, does the part need to be replaced?

 

P0446 = EVAP canister vent control valve. The EVAP canister vent control valve is located on the EVAP canister and is used to seal the canister vent. This solenoid valve responds to signals from the ECM. When the ECM sends an ON signal, the coil in the solenoid valve is energized. A plunger will then move to seal the canister vent. The ability to seal the vent is necessary for the on board diagnosis of other evaporative emission control system components.

This solenoid valve is used only for diagnosis, and usually remains opened.

When the vent is closed, under normal purge conditions, the evaporative emission control system is depressurized and allows “EVAP Control System (Small Leak)” diagnosis.

P1490 = vacuum cut valve bypass valve. The vacuum cut valve and vacuum cut valve bypass valve are installed in parallel on the EVAP purge line between the fuel tank and the EVAP canister.

The vacuum cut valve prevents the intake manifold vacuum from being applied to the fuel tank.

The vacuum cut valve bypass valve is a solenoid type valve and generally remains closed. It opens only for on board diagnosis. The vacuum cut valve bypass valve responds to signals from the ECM. When the ECM sends an ON (ground) signal, the valve is opened. The vacuum cut valve is then bypassed to apply intake manifold vacuum to the fuel tank.

This is located by the EVAP canister, attached to the chasis.

 

Seems like a mess under there.
Would anyone have an actual photograph of the vacuum cut valve bypass valve?

 

Don't lose this picture...

 

I agree with infinimax96 and DennisMik. Replace the valves and clear your codes. make sure you drive it for at least one drive cycle before taking it to any emissions test and your should be golden.

 

Thanks a million for the clear picture DennisMik, helps a lot.
Will be looking at this tonight hopefully.
My hope is that it's a loose power connector due to the undercoating work done recently, hopefully no parts were damaged.