DTC Parameters
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
- Engine is running
DTC P1640 will set if A/C relay, main relay, EVAP vent solenoid or EVAP purge solenoid feedback voltage is more than 3.5 volts for more than 6 seconds when that device is commanded ON.