Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Use a scan tool in order to inspect the Passlock™ data voltage and the Passlock™ code.
Inspect the Passlock™ sensor harness for an intermittent or a short to battery. Refer to TESTING WIRING SYSTEMS FOR INTERMITTENT & POOR CONNECTIONS in Wiring Systems.
You may be directed to this table from the VTD Diagnostic System Check without a DTC B2958 being set. If you were directed to this table, follow all of the steps in this diagnostic table.
When directed to this table, DTC B2958 may have a history status.