Note On Intermittents

Check for intermittent short to ground in circuit No. 434. A stall or a near stall condition which may set Code P054 or P095 and may cause a false Code P091 to set due to engine transition from running to not running (or near stall) then back to running without transaxle switch being in Park or Neutral.

Fig 1: Code P091 Schematic, Transaxle Range Switch Problem

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P091 Diagnostic Flow Chart, Transaxle Range Sw. Problem

Courtesy of GENERAL MOTORS CORP.