P0452 NVLD Pressure Switch Stuck Closed - With Automatic Transmission
Possible Causes Setting Conditions
EVAP purge solenoid control circuit is shorted to ground
NVLD assembly has failed (the switch may be stuck closed)
NVLD connector is damaged (check pins for damage, and for moisture)
NVLD switch signal circuit is shorted to ground
PCM has failed
Vac Leak
Engine started; and immediately after engine startup, the PCM activates the NVLD solenoid to test the NVLD switch circuit. If the PCM does not detect that the switch is open under these conditions, DTC P0452 is set.

This code sets in 2 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)