GM Service Manual Online
For 1990-2009 cars only
Battery Charger: The scan tool displays On/Off. The scan tool displays On when the engine is OFF and battery voltage is greater than 13.5 Volts.

Battery State: The scan tool displays Low Voltage/Normal/High Voltage. The scan tool displays Low Voltage below 9.0 Volts and returns to Normal when battery voltage returns to above 9.5 Volts. High Voltage is displayed above 16.0 Volts and returns to Normal when battery voltage returns to below 15.5 Volts.

Battery Voltage: The scan tool displays a voltage. The scan tool displays the battery voltage as calculated by the module or received as a class 2 message.

Crank Request: The scan tool displays Yes/No. The scan tool displays Yes when the ignition is placed in the Start position and a battery voltage is received by the PCM.

Clutch Start Switch: The scan tool displays On/Off. The scan tool displays On when the clutch is depressed.

GEN L-Terminal Signal Command: The scan tool displays On/Off. The scan tool displays Off until the engine is running, then the PCM supplies a 5.0 V signal to turn ON the regulator, then On is displayed.

GEN F-Terminal Signal: The scan tool displays 0-100%. The scan tool displays the percentage of generator On time, the higher the percentage the greater the generator output.

PNP Switch: The scan tool displays P-N/R-D-L. The scan tool displays P-N when the transmission is in the Park (P) or Neutral (N) position.

Start Disabled: The scan tool displays Yes/No. The scan tool displays No unless the VTD receives improper key information, then Yes will be displayed and starting will be disabled.

Starter Motor Status: The scan tool displays Turning/Not Turning. The scan tool displays Turning during cranking until a run flag is received by the PCM.

Starter Relay Command: The scan tool displays On/Off. The scan tool displays On when the PCM has received all of the requirements for starting the engine.