Code P031, Shorted Map Sensor Circuit: Action

WARNING: This page is about a different car, the 1995 Cadillac Seville. However, it is still accessible from the selected car via links, so may be relevant.

PCM turns on MIL, disables long term fuel trim and uses a substitute MAP sensor value based on engine RPM and throttle switch status (open or closed). PCM disables torque management and transaxle shift adapts are maintained at current levels.

NOTE: Test numbers refer to numbers on diagnostic chart.

If Code P038 is set, check circuit No. 452 for open or short to voltage. MAP and IAT sensors share this same circuit.
PD02 will read 103-105 kPa if MAP sensor or circuit is shorted.
If PCM data PD02 goes to 10-16 kPa with connector unplugged, check for faulty sensor or circuit.
Checks circuit No. 432 for short to battery. If circuit is okay, replace PCM.