P0449

DTC P0449

CIRCUIT DESCRIPTION
An ignition voltage is supplied directly to the evaporative emission (EVAP) canister vent valve. The control module controls the EVAP vent valve by grounding the control circuit via an internal driver switch. The primary function of the driver is to supply ground for the controlled component. The control module monitors the status of the driver. If the control module detects an incorrect voltage for the commanded state of the driver, DTC P0449 sets.

DTC DESCRIPTORS
This diagnostic procedure supports the following DTC:
DTC P0449 Evaporative Emissions (EVAP) Vent Solenoid Control Circuit

CONDITIONS FOR RUNNING THE DTC
- DTC P0606 is not set.
- The ignition 1 voltage is more than 11 volts.
- DTC P0449 runs continuously once the above conditions are met.

CONDITIONS FOR SETTING THE DTC
The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match, for more than 1 second.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/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.

TEST DESCRIPTION

Steps 1-5:

Steps 6-13:

Steps 14-15:

The numbers below refer to the step numbers on the diagnostic table.
2. A click should be heard or felt when the valve operates. Ensure that both the ON and the OFF states are commanded. Repeat the commands as necessary.
5. This step verifies that the ECM is providing ground to the EVAP vent valve.
6. This step tests if the EVAP vent valve control circuit is grounded.