Code P071, Intermittent Map Sensor: Action

PCM uses substitute MAP value based on engine RPM and throttle position switch status.

1. Checks if MAP can read BARO pressure correctly (85-105 kPa).
2. Checks MAP sensor's ability to react to a known vacuum (26-34 kPa).
3. Checks MAP sensor's ability to react to sudden change in vacuum.

Fig 1: Code P071 Schematic, Intermittent MAP Sensor

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P071 Schematic, Intermittent MAP Sensor

Courtesy of GENERAL MOTORS CORP.

Fig 3: Code P071 Diagnostic Flow Chart, Intermittent MAP Sensor

Courtesy of GENERAL MOTORS CORP.