1996 GM Trucks & Vans (GM Service Bulletin No. 66-71-03A)
WARNING: This page does not describe the selected car, but rather 14 other vehicles, including the 1998 GMC Savana Special, 1998 GMC Savana Camper Special, 1998 GMC Savana, 1998 Chevrolet RV Cutaway, and 1998 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
Some owner's may complain that vehicle has either a slip or flare on 1-2 and/or 2-3 upshift, or no 3rd or 4th gear. DTC P1870 may also be present. This condition may be caused by a poor internal ground between 2 circuit boards of Vehicle Control Module (VCM), which can cause VCM to command erratic line pressure at pressure control solenoid. To correct this condition, a revised Wiring Harness (12167310) has been designed to replace current wiring harness at VCM. Corrections were made to VCM beginning February 14, 1996. Corrected VCM's are identified by service number 16244210, located on VCM identification label.