Manifold Pressure/Vacuum Sensor: Testing and Inspection

A Tech 1 scan tool displays manifold pressure in kPa and Manifold Absolute Pressure (MAP) sensor signal voltage. Low pressure (high vacuum) displays a low voltage while a high pressure (low vacuum) displays a high voltage. A fault in the MAP sensor circuit should set a Diagnostic Trouble Code (DTC) 33 MAP Sensor Circuit (Signal Voltage High) or DTC 34 MAP Sensor Circuit (Signal Voltage LOW) and using the applicable chart will lead to the cause of the problem. A DTC 33 or 34 may set if a rough or unstable idle exists. Chart C-1D Manifold Absolute Pressure (MAP) Output Check can also be used to check the MAP sensor. Testing and Inspection