P2422

DTC P2422

SYSTEM DESCRIPTION
A restricted or blocked evaporative emission (EVAP) vent path is detected by the control module commanding the purge valve ON (open) and the vent valve ON (closed) allowing a vacuum to be applied to the EVAP system. Once a calibrated vacuum level has been reached, the control module commands the purge valve OFF (closed) and the vent valve OFF (open) while monitoring 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, DTC P2422 will set.




The table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister purge and vent valves.

DTC DESCRIPTORS
This diagnostic procedure supports the following DTC.
DTC P2422 Evaporative Emissions (EVAP) Vent System Performance

CONDITIONS FOR RUNNING THE DTC
- Before the engine control module (ECM) can report DTC P2422 failed, DTCs P0441, P0442, and P0456 must run and pass.
- DTCs P0106, P0107, P0108, P112, P0113, P0117, P0118, P0122, P0123, P0131, P0132, P0133, P0134, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204 P0402, P0404, P0405, P0406, P0443, P0452, P0453, P0462, P0463, P0488, P0502, P2195, and P2196 are not set.
- The barometric pressure (BARO) is more than 72 kPa.
- The engine coolant temperature (ECT) at start-up is more than - 5°C (23°F).
- The intake air temperature (IAT) at start-up is less than 40°C (104°F).
- The start-up IAT minus the startup ECT is within 12°C (22°F).
- The start-up ECT minus startup IAT is within 50°C (90°F).
- The start-up IAT minus IAT are within 3°C (5°F).
- The ignition 1 voltage is between 11-16 volts.
- Purge start time is less than 360 seconds.
- Engine Run Time is more than 1 second and less than 120 seconds.
- The fuel level is between 1/4 and 3/4.
- DTC P2422 runs once an ignition cycle when the above conditions are met.

CONDITIONS FOR SETTING THE DTC
- Fuel tank pressure is more than 9.3 mm Hg (5 inch H2O) or less than -4.7 mm Hg (-2.5 inch H2O) at cold engine startup.
- The above condition is present for at least 2 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 vent valve inlet or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem.

TEST DESCRIPTION

Steps 1-2:

Steps 3-4:

Steps 5-6:

Steps 7-13:

Steps 14-15:

The number below refers to the step number on the diagnostic table.
4. This test determines if the FTP sensor is operating correctly.