Code P071, Intermittent Map Sensor Signal: Action

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

1. Checks if MAP can read BARO pressure correctly (87-105 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 (4.6L - 1 Of 2)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P071 Schematic (4.6L - 2 Of 2)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Code P071 Flow Chart (4.6L)

Courtesy of GENERAL MOTORS CORP.