GM Service Manual Online
For 1990-2009 cars only

Powertrain Control Module (PCM)

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON/Engine OFF

(8.1L, L18)

Ignition 1 Signal

Engine 1, 2 Data

Volts

12v

GEN L--Terminal Signal Command

Engine 2 Data

OK/No Voltage

OK

GEN F--Terminal Signal

Engine 2 Data

%

10-90%