Note On Intermittents

Manipulate affected wiring and connectors while observing PCM parameter P.0.2. Apply and release vacuum to MAP sensor vacuum port using a vacuum source. If PCM parameter P.0.2 displays greater than 108 kPa, condition has been induced and cause of intermittent should be repaired. If wiring and connectors are okay, substitute a known good MAP sensor, and retest.

Fig 1: PCM Code E31 Schematic - Shorted MAP Sensor Circuit

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code E31 Flow Chart - Shorted MAP Sensor Circuit

Courtesy of GENERAL MOTORS CORP.