GM Service Manual Online
For 1990-2009 cars only
ATC Application: The scan tool displays a numeric value. This parameter indicates the model number assigned to the transfer case.

ATC Software ID: The scan tool displays a numeric value. This parameter indicates the numbers or characters assigned to the current version of software used in the ATC module.

Battery Voltage: The scan tool displays a range of 0-25.5 volts. This parameter indicates the voltage measured by the transfer case shift control module at its battery feed.

Current Slip Adapts: The scan tool displays a numeric value. This parameter indicates corrective adjustments made by the transfer case shift control module for wheel slip events.

Front Propshaft Speed: The scan tool displays a range of 0-8,192 RPM. This parameter indicates the rotational speed of the front propshaft.

Ignition Cycles Since Last Current DTC: The scan tool displays a numeric value. This parameter indicates how many ignition cycles have occurred since last current DTC was set.

Motor A Current: The scan tool displays Amps. This parameter indicates current flow when the motor moves one of two directions.

Motor B Current: The scan tool displays Amps. This parameter indicates current flow when the motor moves one of two directions.

Rear Propshaft Speed: The scan tool displays a range of 0-8,192 RPM. This parameter indicates the rotational speed of the rear propshaft.

Service 4WD Lamp: The scan tool displays ON or OFF. This parameter indicates if the Service 4WD Lamp is being commanded by the transfer case shift control module.

Slip Adapt PWM: The scan tool displays a range of 0-100 percent. This parameter indicates the Duty Cycle applied to the ATC motor.

Total Slippage: The scan tool displays a range of 0-8,192 RPM. This parameter indicates the total slippage of both the front and rear propshafts.