Note On Intermittents

With ignition on, backprobe PCM terminal C9 to ground using a 12-volt test light. Light should remain on unless steering is turned to full lock position. Manipulate power steering pressure switch connector, circuit No. 495 and PCM terminal C9 connector while observing test light. If light goes out, repair intermittent open or short to ground.

Fig 1: PCM Code E40, Schematic, Power Steering Pressure Switch Ckt

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code E40, Flow Chart, Power Steering Pressure Switch Ckt

Fig 3: PCM Code E40