Note On Intermittents

Manipulate affected wiring and connectors while observing PCM parameter PD02. Apply and release vacuum to MAP sensor vacuum port using a vacuum source. If PCM parameter PD02 displays greater than 108 kPa, condition has been induced and intermittent should be repaired. If wiring and connectors are okay, substitute a known good sensor, and retest.

Fig 1: PCM Code P031 Schematic - Shorted MAP Sensor Circuit

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code P031 Flow Chart - Shorted MAP Sensor Circuit

Courtesy of GENERAL MOTORS CORP.