OBD code P0499, P0499 NVLD Canister Vent Valve Solenoid, Cause?

p04099 ( p zero ,not P 'oh"
you wrote all that down wrong, no five digits allows.
learn to see them and write them down properly
my Spidy senses tell me it is this

Trouble Code: P0499 (3.7L V6 VIN K Auto)
NVLD Canister Vent Solenoid Circuit High
Trouble Code Conditions:
Key on or engine running. The PCM detected an open or unexpected high voltage condition on the Natural Vacuum Leak Detection (NVLD) circuit.

Possible Causes:

NVLD canister vent solenoid control circuit is open or is shorted to power

NVLD canister vent solenoid ground circuit is open

NVLD canister vent solenoid is damaged or it has failed

This code has nothing to do with the purge valve . Evap vent valve . Has nothing to do with intake manifold.
An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP canister vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem.
• An EVAP canister, vent hose or vent solenoid valve that has restricted flow may cause this DTC to set. Using purge solenoid valve command with a scan tool will allow vacuum to be applied to the system instead of pressure. With the EVAP canister vent solenoid valve open and the EVAP canister purge solenoid valve commanded to 100 percent, vacuum should not increase to more than 9 inches H2O.
Your best bet , take it to a qualified repair shop.

code p 0499 refers to emission evaporative system vent control---circuit high===causes ---wiring short to positive ---EVAP valve
replace the EVAP valve

DTC P0446: Evaporative Emissions (EVAP) Vent System Performance
Circuit/System Description
This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path. The control module commands the EVAP canister purge solenoid valve Open and the EVAP canister vent solenoid valve Closed. This allows vacuum to be applied to the EVAP system. Once a calibrated vacuum level has been reached, the control module commands the EVAP canister purge solenoid valve Closed and the EVAP canister vent solenoid valve Open. The control module monitors the fuel tank pressure (FTP) sensor for a decrease in vacuum. If the vacuum does not decrease to near 0 inch H2O in a calibrated time, this DTC sets.
Diagnostic Aids
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An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP canister vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem.

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An EVAP canister, vent hose, or vent solenoid valve that has restricted flow may cause this DTC to set. Using a purge solenoid command with a scan tool will allow vacuum to be applied to the system instead of pressure. With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 5 inches H2O.

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An EVAP canister filter that is restricted can cause this DTC to set. Refer to Evaporative Emission Canister Replacement .

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Disconnecting one component at a time while the EVAP system is under flow will help to pinpoint a restriction in the system

Do you have a scan tool that reads data PID'S ?
Your FTP - fuel tank pressure sensor could be at fault !

Ignition ON and fuel cap removed, verify that the FTP sensor parameter is between 1.3-1.7 volts. ?‡'
If not within the specified range, go to the FTP sensor section in Circuit/System Testing.

1. Install the fuel cap.
2. With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 12 inches H2O.

?‡'
If the fuel tank vacuum is greater than the specified range, go to the restriction section in Circuit/System Testing.

If

Trouble Code: P0499

NVLD Canister Vent Solenoid Circuit High

Possible Causes:


NVLD canister vent solenoid control circuit is open or is shorted to power.NVLD canister vent solenoid ground circuit is open.NVLD canister vent solenoid is damaged or it has failed.PCM has failed.Mr. Perkins,here are the causes for the code.

Hi there:

A code P0446 could mean one or more of the following has happened:
- Faulty vent valve
- Open, short or excessive resistance on Vent valve control circuit
- Blockage of vent valve
- Bad PCM




With a P0446 OBD-II trouble code, here are some things to try:
- Replace Vent valve
- Repair open, short, or resistance problem in control circuit
- Repair open, or short, or resistance problem in power circuit

- Replace PCM




Hope this helps.

Hi, your vent valve has malfuntioned. The vent valve is near the tank, and has a hose to the tank and a solenoid to close it. Check the wiring/connector. If OK, try applying 12 volts directly to the solenoid. If it does not click when voltage is applied, replace the solenoid/valve.

P0446 Evaporative Emmission Control System Vent Control Circuit OBD-II Trouble Code Technical Description

Evaporative Emission Control System Vent Control Circuit Malfunction
What does that mean? Evap vent valve has only one purpose. It closes in order to seal the vent so the EVAP system can pressurize and ensure there are no leaks. Evap vent valve is usually supplied Batt. voltage with key on. The ECM's driver controls the ground, and when grounded, activates the valve (closing it). If the ECM detects a short to ground, and open,or a short to battery voltage on the control circuit, P0446 will set. Code also may refer to ECM detecting that EVAP system is unable to achieve or maintain vacuum during test.
Symptoms There will be no obvious symptoms to driver, other than MIL illumination.
Causes A code P0446 could mean one or more of the following has happened:

• Faulty vent valve
• Open, short or excessive resistance on Vent valve control circuit
• Blockage of vent valve
• Bad PCM

Possible Solutions With a P0446 OBD-II trouble code, here are some things to try:

• Replace Vent valve
• Repair open, short, or resistance problem in control circuit
• Repair open, or short, or resistance problem in power circuit
• Replace PCM

CODE PO499 - NVLD CANISTER VENT SOLENOID CIRCUIT HIGH. SOUND LIKE THE NVLD CANISTER VENT SOLENOID IS FAULTY.

p0499- nvld canister vent valve solenoid circuit high, replace the carbon cannister vent solenoid.

P0499 Evaporative Emission System Vent Valve Control Circuit High, REPLACE THE SOLENOID.