Torque_Wrench

iTrader: (13)

Hey bro, you got a bad Evap Vent Soleniod Valve.....very common! It's a bullshit part but you gotta have it. This should help you out......

DTC P0446
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 inches H2O in a calibrated time, this DTC sets.

The following table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent solenoid valves.

Control Module Command
EVAP Canister Purge Solenoid Valve
EVAP Canister Vent Solenoid Valve

ON
Open
Closed

OFF
Closed
Open


Conditions for Running the DTC
• DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0135, P0136, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0156, P0157, P0158, P0160, P0161, P0220, P0442, P0443, P0449, P0452, P0453, P0455, P0502, P0503, P1111, P1112, P1114, P1115, P1121, P1122, P1125, P2135 are not set.

• The ignition voltage is between 10-18 volts.

• The barometric pressure (BARO) is more than 75 kPa.

• The fuel level is between 15-85 percent.

• The engine coolant temperature (ECT) is between 4-30°C (39-86°F).

• The intake air temperature (IAT) is between 4-30°C (39-86°F).

• The start up ECT and IAT are within 9°C (16°F) of each other.

Conditions for Setting the DTC
• The fuel tank pressure sensor is less than -10 inches H2O.

• The above condition is present for more than 30 seconds.

Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
• The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

• A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
• 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.

• For intermittent conditions, refer to Intermittent Conditions .

• 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

Randy_S

iTrader: (1)

So where is it on the truck then? Is it gonna be a dealer item or can I pick one up at OReilly/AutoZone?

Randy_S

iTrader: (1)

Thanks for your help man but can you tell me where the Evap Vent Soleniod Valve is??

Torque_Wrench

iTrader: (13)

It's a dealer only item. The Vent Valve is located under the truck toward the rear where the fuel tank is. It's a round black canister, smallish about the size of a coffe cup.

Randy_S

iTrader: (1)

Thanks bro

Torque_Wrench

iTrader: (13)

Anytime brotha'...that's why we're here....