GM Service Manual Online
For 1990-2009 cars only
Crank Request Signal: The scan tool displays Yes/No. The scan tool displays No until the ignition is placed into the START position then Yes is displayed.

Electronics Battery FD: The scan tool displays 0-20  Volts. The scan tool displays the voltage as received on the battery positive voltage circuit of the BCM.

GEN F-Terminal Signal: The scan tool displays 0%-100%. The scan tool displays 0%-10% until the engine is started and the PCM receives a signal from the generator then 5%-95% is displayed depending on electrical loads.

GEN L-Terminal Signal Command: The scan tool displays On/Off. The scan tool displays Off until the engine is running, then the scan tool should display On.

Ignition 1 Signal: The scan tool displays 0-20 Volts or ON / OFF. The scan tool displays the voltage as received on the Ignition 1 circuit to the PCM.

Starter Relay Circuit History : The scan tool displays Fault/OK/Invalid State. The scan tool displays Fault until the ignition is placed into the START position then OK is displayed.

Starter Relay Command: The scan tool displays ON/OFF. The scan tool displays Off until the ignition is placed into the CRANK position, then it reads On.