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

General Description


The fuel tank pressure (FTP) sensor output is near atmospheric pressure (0 kPa (0 mmHg, 0 inHg)) before purge starts since the evaporative emission (EVAP) canister vent shut valve is normally open (to the atmosphere). The sensor indicates a negative pressure value (vacuum) while purging. When the FTP sensor indicates vacuum after the engine starts, an FTP sensor zero point shift failure or an EVAP canister vent shut valve stuck closed can occur. To prevent these failures, the powertrain control module (PCM) monitors the FTP sensor output after purge starts. The PCM detects a malfunction of the EVAP canister vent shut valve if the output indicates excessive vacuum. However, if the fuel tank internal pressure is below the specified value (excessive vacuum is detected) when starting the engine, the malfunction detection should be done as follows because it is difficult to distinguish between FTP sensor range problem (P1454) and an EVAP canister vent shut valve stuck closed problem (P2422).
1.
If neither Pending DTCs (P1454 nor P2422) are stored, both Pending DTCs are stored when excessive vacuum is detected at engine start.
2.
If both Pending DTCs (P1454 and P2422) are stored and excessive vacuum is detected, both Confirmed DTCs are stored.
3.
If either Pending DTC (P1454 or P2422) is stored and excessive vacuum is detected, the PCM stores the Confirmed DTC which the Pending DTC is stored.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Once per driving cycle
Sequence**
P0452, P0453 are judged as OK
Duration
1.04*, 8.0** seconds or more
DTC Type
Two drive cycles, MIL on
*: Elapsed time after the FTP sensor output exceeds the malfunction threshold.
**: Excessive negative pressure is detected.

Enable Conditions
Condition
Minimum
Maximum
Elapsed time after starting the engine**
10 seconds
–
Engine coolant temperature [ECT SENSOR 1]***
131 °F (55 °C)
–
12 volt battery voltage [BATTERY]*
10.5 V
–
Fuel feedback
Closed loop
Other**
The EVAP canister vent shut valve is open
The EVAP canister purge valve is closed (the system is not purging)
***: Condition to start the purge control
[ ]: HDS Parameter

Malfunction Threshold
The output from the FTP sensor [FTP SENSOR] is -4 kPa (-25 mmHg, -1.0 inHg)*, -2 kPa (-10 mmHg, -0.4 inHg)** or less for at least 1.04*, 8.0** 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 drain tube clogged

Confirmation Procedure
Operating Condition
1.
Start the engine, and let it idle until the radiator fan comes on.
2.
When the diagnosis does not finish at idle, drive at 30 - 75 mph (48 - 120 km/h) at EVAP canister purge valve duty [EVAP PC DUTY] 20 % or more.
Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
With the HDS
None.

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 or by disconnecting the 12 volt battery.