Sensor Question

[JTesta1966 at aol.com]

In a message dated 6/16/99 12:20:00 PM Eastern Daylight Time, 
spectro at ma.ultranet.com writes:

<< The unit mounts directly to the module and appears to be a small
 pressure sensor referenced to tank atmosphere. I've been finding them on my
 weekly scrounging run to the local GM dumpster ;) >>

Probably used for the OBDII evap test. If I remember right, GM cars use 
engine vacuum to pull a vac, then the ECM tests to see if it holds. Has to be 
a sensor of some kind to tell press/vac. Also, maybe it tells the ECM the 
tank is getting pressurized (hot day) and the ECM runs a purge cycle. One of 
the programming guru's would know tha one.

Jim