Diagnostic Aids
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.
Inspect wiring for poor connections at VCM. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Check for broken wire inside insulation. If diagnosing for intermittent short or open condition, move wiring harness while observing scan tool for value change. First diagnose and clear any engine and TP sensor DTCs that are present, then inspect for any transmission DTCs that may have reset. Low oil pump pressure and a slipping transmission can cause DTC P1875 to set.
NOTE:
After repair is complete, a harsh shift condition may exist. This condition is caused by steady state adapts. To clear steady state adapt cells, remove battery power from VCM for 60 seconds. Then reconnect battery and drive vehicle.