DTC Advanced Diagnostics: P2422
DTC P2422:Evaporative Emission (EVAP) Canister Vent Shut Valve Stuck Closed Malfunction

General Description

A stuck closed evaporative emission (EVAP) canister vent shut valve is detected either by monitoring the fuel tank pressure during canister purging or during the EVAP system leak monitor. The fuel tank pressure is continuously compared with a rationality threshold when the monitoring conditions are fulfilled. Initially the fuel tank pressure is monitored when canister purging is active. Purging commences with the simultaneous opening of both the EVAP canister purge valve and the EVAP canister vent shut valve. If the EVAP canister vent shut valve was stuck closed, then canister purging will build a progressive vacuum that will eventually damage the fuel tank. To prevent fuel tank damage, the EVAP canister purge valve is commanded to close when the fuel tank pressure falls below a low rationality threshold. If the fuel tank pressure is less than the low rationality threshold for a calibrated amount of time, the powertrain control module (PCM) detects a malfunction and stores a DTC. If a stuck closed EVAP canister vent shut valve could not be detected during canister purging, then another EVAP canister vent shut valve stuck check will be performed during the EVAP system monitor using tighter fault threshold. First, both the EVAP canister vent shut valve and the EVAP purge valve are commanded open and the fuel tank pressure is monitored during the ensuing canister purging. If the fuel tank pressure reaches a low rationality threshold, the EVAP purge valve is commanded to close and if the fuel tank pressure remains below this rationality threshold for calibrated amount of time, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Multiple
Sequence
None
Duration
0.5 second or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
During canister purging
Condition
  
Vehicle
ON mode

During EVAP system monitor (conditions to trigger EVAP system monitor)
Condition
Minimum
Maximum
Elapsed time after starting the engine
9 minutes 10 seconds
–
Outside air temperature
32 °F (0 °C)
103.6 °F (39.8 °C)
Initial engine coolant temperature
[ECT Sensor 1]
32 °F (0 °C)
113 °F (45 °C)
Barometric pressure [Baro Sensor]
74 kPa (555 mmHg, 21.9 inHg)
–
Fuel tank pressure
-4 kPa (-30 mmHg, -1.1 inHg)
4 kPa (30 mmHg, 1.1 inHg)
Change in ambient pressure during vacuum build*
–
1.602 kPa (12.01 mmHg, 0.473 in Hg)
12 volt battery voltage [Battery]
10.7 V
16 V
Fuel level
1 L (0.3 US gal)
42 L (11.0 US gal)
Other
No fault suspicion in mixture adaptation
*: For at least 5 minutes
[ ]: HDS Parameter

Malfunction Threshold
During canister purging
Canister purge mass flow is 0 kg/h (0 lbs/h) for at least 2 seconds.
During EVAP system monitor
The fuel tank pressure is less than -2.25 kPa (-16.87 mmHg, -0.664 inHg) for at least 5 seconds.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
EVAP canister vent shut valve closed stuck
EVAP canister vent shut valve blocked by dirt

Confirmation Procedure
Operating Condition
1.
Start the engine and drive the vehicle for a while.
2.
Stop the vehicle and let it idle for 10 minutes.
Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.