Scan Tool Testing and Procedures

Transfer Case Shift Control Module Scan Tool Information (BW4477)

The Transfer Case Shift Control Module Scan Tool Data List contains all transfer case related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.

The values below represent a typical display recorded from a properly functioning system.

Important: Do not use a scan tool that displays faulty data. Report the condition to the scan tool manufacturer. The use of a faulty scan tool can result in misdiagnosis and the unnecessary replacement of parts.


Only the parameters listed below are used/referenced in this manual for diagnosis. If a scan tool displays other parameters, those values are not recommended by General Motors for use in diagnosis.

If all values are within the expected range described below, refer to Symptoms - Transfer Case Symptoms - Transfer Case for diagnosis.

The scan tool values from a properly functioning transfer case may be used for comparison with the transfer case you are diagnosing. The values below represent a typical display recorded from a properly functioning system.