Diagnostic Aids

Check for proper TP sensor operation. If TCC is mechanically stuck on, vehicle speed is zero, brakes are applied, and D2 is selected, TCC fluid will mechanically apply the TCC, causing an engine stall.

Fig 1: Code 85 Schematic (5.7L) TCC Stuck On

Fig 2: Code 85 Diagnostic Flow Chart (5.7L) TCC Stuck On