DTC 31, Map Sensor, Open Or Shorted Circuit: Notes

MAP sensor responds to changes in intake manifold pressure (vacuum). MAP sensor consists of a semi-conductor type pressure converting element which converts a pressure change into an electrical change and an electrical circuit which amplifies and corrects electrical change. PCM applies 5 volts to MAP sensor. Changes in pressure, resulting from engine load and RPM, are converted into voltage input monitored by PCM. A low voltage input at PCM indicates low manifold pressure and a high voltage input at PCM indicates high manifold pressure. DTC 31 will set if voltage input at PCM indicates either very low or very high manifold pressure for at least 0.5 second.

1. Checks for an open or short to ground in Yellow wire between PCM and MAP sensor.
2. Checks for an open in Light Green/Red wire between PCM and MAP sensor.
3. Checks for an open in Brown wire between PCM and MAP sensor, and for a faulty PCM or MAP sensor.