Cadillac Repair: deville 1997 code p1645, variable voltage, voltage supply

Question
What part need to be replaced if the code for p1645 is showing an evaporative emission(evap)vent solenoid control
circuit

Answer
Fault could be:

Evaporative Emission Vacuum Purge Switch which has a PURPLE and a Black/White wire connected to it. Do NOT use battery voltage to test this device as it is a LOW CURRENT variable voltage supply line from the computer.

Could be:

Evaporative Emission Control Solenoid which has a PINK and a DARK GREEN/WHITE wire attached to it.

Could Be:

PCM (computer).

Requires a scanner to test each device.