The CIS-E control unit has diagnostics built into it.

For your year and model:

Ignition on, engine off - 70% = Federal version control unit, 85% = California version control unit.

Engine at idle - oscillating reading indicates no malfunctions in system, otherwise -

0% = CIS-E control unit receives no voltage or is defective.
10% = idle speed contact
20% = full load contact
30% = coolant temperature sensor
40% = Air flow sensor position indicator
50% = O2 sensor
60% = not used
70% = TD signal
80% = altitude correction capsule