Bench ecms

[Bruce Plecan]

I had been told the sensor grounds on a gm ecm floated in reference to the
chassis ground, well that doesn't appear to be correct, everything is just a
couple tenths of an ohm from true ground.
With no displayed voltage drops across grounds.
While still seperated, does it really matter if sensor grounds go to
chassis, on an actual car?.    If so then where Have I strayed to having
had sensor ground problems????....


For coolant temp, and intake air temps, I was just going to share
resistances.  Tieing grounds together.

For TPS, and MAP I was going to tie the grounds together, use the
+5 from one ecm, and then share the sensor's output.
YES/NO??????..

Cheers
Bruce        RPM signals applied to both ecms, and powered up
                  leds flashed and no problems today.
                  The cat has grown boarded with the flashing LEDs,
                  but the staff is acting like their inna stupor.