The Automatic Transfer Case Scan Tool Data Definitions contain a brief description of all ATC related parameters available on the scan tool. The list is in the order it appears on the scan tool.

TP (Throttle Position) Angle: Displays a range of 0-100 %. The TP Angle is computed by the VCM from the TP sensor voltage. The TP Angle should read 0 percent at idle and 100 percent at wide-open throttle (WOT).

Front Propshaft Speed: Displays a range of 0-8192 RPM. This parameter indicates the rotational speed of the front propshaft.

Rear Propshaft Speed: Displays a range of 0-8192 RPM. This parameter indicates the rotational speed of the rear propshaft.

ATC Slip Speed: Displays a range of 0-8192 RPM. This parameter indicates the RPM difference between the front and rear propshafts.

Slip Adapt PWM: Displays a range of 0-100 %. This parameter indicates the duty cycle applied to the ATC motor.

Last Adapt Highest PWM: Displays a range of 0-100 %. This parameter indicates the highest duty cycle applied to the ATC motor during the last slip event.

Ignition 3: Displays a range of 0-25.5 volts. This parameter indicates the voltage measured by the transfer case shift control module at its ignition feed.

AWD Enabled: The scan tool displays YES or NO. This parameter indicates if the transfer case shift control module is currently attempting to prevent front to rear propshaft slip.

AWD Lamp Open: The scan tool should always display NO. This parameter is not used by S/T vehicles. This parameter indicates that an open or short to ground is sensed in the SERVICE indicator (AWD/4WD) lamp circuit.

AWD Lamp Shorted: The scan tool should always display NO. This parameter is not used by S/T vehicles. This parameter indicates that a short to power is sensed in the SERVICE indicator (AWD/4WD) lamp circuit.

Motor A or B Short to Volts: The scan tool displays YES or NO. When the ATC motor relay is commanded off, YES indicates that voltage is sensed on either the Motor A or B terminals.

Motor A or B Short to Gnd.: The scan tool displays YES or NO. When the ATC motor is commanded ON, YES indicates that current is flowing through part of the circuit to a short to ground and that no voltage is sensed at the Motor B terminal.

Motor Ground Circuit Open: The scan tool displays YES or NO. When the ATC motor is commanded ON, YES indicates no current flow and system voltage is sensed at both Motor A and B terminals.

Motor A or B Circuit Open: The scan tool displays YES or NO. When the ATC motor is commanded ON, YES indicates no current flow and no voltage is sensed at the Motor B terminal.

Motor A or B Circuit Fault: The scan tool displays YES or NO. YES indicates that one of the above motor circuit faults has been detected.

Rear Propshaft Signal Fault: The scan tool displays YES or NO. YES indicates a DTC C0300 (Rear Speed Sensor Malfunction) has been detected, but the code will not set unless the fault is present for 30 seconds.

Front Propshaft Signal Fault: The scan tool displays YES or NO. YES indicates a DTC C0305 (Front Speed Sensor Malfunction) has been detected, but the code will not set unless the fault is present for 30 seconds.

Software ID: The scan tool displays a four-digit number. This parameter indicates the transfer case shift control module calibration version number.

GM Part Number: The scan tool displays an eight-digit number. This parameter indicates the transfer case shift control module GM software number.