Manifold Pressure/Vacuum Sensor: Testing and Inspection

There is no practical test for this device since it is built into the ECU and communicates internally with the other functions of the control unit. A failure of the MAP sensor, however, will result in noticeable symptoms and should store a fault code in the computer memory.

1. If a code 2222 is present, the ECU has detected a fault in the MAP sensor circuit (no signal from MAP sensor), and the ECU must be replaced. This code should be accompanied by the following symptoms:
a. Lack of power.
b. No turbocharger boost (wastegate frequency valve open all the time).
c. No acceleration enrichment (engine stumbles during acceleration, especially at low speeds).

2. If a code 2221 is present, the ECU has noticed that the signal from the MAP sensor is outside the normal range or is fixed when it should be varying. This is most likely caused by the vacuum/pressure hose coming off at one end or being pinched or damaged, blocking or leaking manifold vacuum/pressure. A vacuum/pressure leak in the hose to the ECU may cause an overboost condition because the pressure in the hose during boost is actually less than manifold pressure. If this is the case, a code 2224 should also have been displayed.

NOTE: If the boost pressure gauge in the instrument panel becomes inoperative or fixed, or shows lower than normal boost pressure, even if no codes are present, check the vacuum/pressure hose to the ECU.