The manifold absolute pressure (MAP) sensor responds to changes in the intake manifold pressure (vacuum). A 5 volt reference is applied to the sensor. A variable resistor moves in relation to manifold pressure and sends a voltage signal to the ECU on the 5 volt reference circuit. This voltage signal varies from 1.0-1.5 volts at closed throttle (high vacuum) to 4.0-4.5 volts at wide open throttle (low vacuum).

A substantial change in throttle position and engine speed must precede any substantial change in MAP. If a substantial change in throttle position and engine speed occurs and a change in MAP does not, then an MAP malfunction has occurred.

This is a type B DTC.

The ECU will set DTC 32 after two consecutive driving cycles with the fault active.

The ECU turns the MIL OFF after three consecutive driving trips without a fault condition present. A DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 40°C (72°F) from the start-up coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during that same ignition cycle) or the code clearing procedure has been used.

Always diagnose ANY PCM codes that are present before beginning this diagnostic procedure.

Inspect the MAP sensor vacuum source for leaks, restrictions, or faulty connections.

Inspect the MAP sensor output voltage to the ECU. This voltage represents a barometric reading to the ECU when the engine is not running.

The number(s) below refer to the step number(s) on the diagnostic table.

Important: When comparing the readings from a known good vehicle, compare vehicles which use a MAP sensor having the same color insert or the same hot stamped number.

Important: The electrical connector must remain securely fastened.

Important: After removing the MAP sensor from the intake manifold, replace the MAP sensor to intake manifold seal.

3. If the DVOM and the scan tool display different readings, a poor connection or high circuit resistance may be the problem.

4. Applying 34 kPa (10 Hg) vacuum to the MAP sensor should cause voltage to change. The voltage value obtained from subtracting the second reading from the first should be greater than 1.5 volts. When applying vacuum to the sensor, the change should be instantaneous. A slow voltage changes indicates a faulty sensor.

5. Disconnect the sensor from the intake manifold and gently twist the sensor in order to inspect for intermittent connections. Output changes greater than 0.1 volt indicate a bad connector or connection. If the connection is OK, replace the sensor.