NVG 233-NP1 2 Speed Automatic 4WD Transfer Case

Circuit Description
The Automatic 4WD Transfer Case (ATC) Control Module uses the VIN information for calculations that are required for the different calibrations used based on axle ratio, transmission, tire size, and engine. The system does not know which calibration to use without this information.

Conditions for Setting the DTC
The Auto Transfer Case (ATC) Control Module does not receive a valid VIN digit for the correct application, K truck, L van or T truck within 3 seconds after power up.

Action Taken When the DTC Sets
- The ignition counts since last fault will be cleared.
- The system will be disabled until valid VIN data is received.
- The Service AUTO/4WD lamp will be latched on.

Conditions for Clearing the MIL/DTC
A history DTC will clear after a valid VIN digit is received.

Possible Causes
Class 2 Data bus malfunction, Vehicle Control Module (VCM)/Powertrain Control Module (PCM) malfunction, module installed in wrong vehicle.