Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 23 other vehicles, including the 1991 GMC Vandura Special, 1991 GMC Vandura, 1991 GMC Value Van, 1991 GMC Suburban, and 1991 GMC Rally Camper Special. However, it is still accessible from the selected car via links, so may be relevant.

Check for poor connections at PCM/TCM and transmission pass-thru connector.

Fig 1: Code 73 Schematic - Force Motor Current (Current Error)

Fig 2: Code 73 Flow Chart - Force Motor Current (Current Error)