GM Service Manual Online
For 1990-2009 cars only
Battery Voltage Signal: The scan tool displays 0-20 volts. The scan tool displays the voltage as received by the module or the 72-08 battery voltage message from the body control module (BCM) over class 2 lines.

Crank Request Signal: The scan tool displays Yes or No. The scan tool displays No until the ignition is placed into the START position then Yes is displayed.

GEN F-Terminal Signal: The scan tool displays 0-100 percent. The scan tool displays the percentage of the field current.

GEN Lamp Command: The scan tool displays On or Off. The scan tool displays the status of the charge indicator as commanded by the engine control module (ECM)/powertrain control module (PCM).

GEN L-Terminal Circuit Status: The scan tool displays Incomplete, Short, GND/Open, Short to B+ or OK. The scan tool displays the status of the GEN L-Terminal circuit.

GEN L-Terminal Command: The scan tool displays 0-100 percent. The scan tool displays the percentage of the GEN L-terminal signal.

GEN L-Terminal Signal Command: The scan tool displays On or Off. The scan tool displays the status of the GEN L-terminal signal.

Idle Boost Level: The scan tool displays the current engine idle boost level in amps as commanded by the PCM.

Ignition 1 Signal: The scan tool displays 0-20 volts. The scan tool displays the voltage as received on the Ignition 1 circuit to the ECM/PCM.

Power Mode: The scan tool displays Off, Accessory, Run and Crank Request. The scan tool displays the state of the ignition switch.

Run/Crank Relay: The scan tool displays On or Off. The scan tool displays the actual state of the Run/Crank relay. It will display On when in a remote start event.

Run/Crank Relay Command: The scan tool displays On or Off. The scan tool displays the commanded state of the Run/Crank relay.

Starter Relay Circuit History: The scan tool displays OK, Open, Short, Invalid State. The scan tool displays the state of the starter relay circuit history.

Starter Relay Circuit Status: The scan tool displays Incomplete, Short, GND/Open, Short to B+ or OK. The scan tool displays the status of the starter relay circuit.

Starter Relay Command: The scan tool displays On or Off. The scan tool displays Off until engine start has been requested, then it reads On.