Pcm Code P031 - Shorted Map Sensor Circuit: Action

PCM turns on SERVICE ENGINE SOON light, sets BARO equal to 92 kPa and uses a substitute MAP sensor value based on engine RPM and throttle switch status (open or closed). PCM disables long term fuel trim.

NOTE: Test numbers refer to numbers on diagnostic chart.

If PCM parameter PD02 goes to 14-106 kPa with sensor unplugged, fault is at MAP sensor or sensor connector.
This checks for an open circuit from terminal "A" of sensor connector to PCM terminal 2A5 (ground). If ground is open, sensor cannot divide reference voltage to make signal voltage vary. Signal voltage is always high.