H29 - Check For Loss of Vacuum to MAP Sensor

- Tee a vacuum gauge into the manifold vacuum line at Manifold Absolute Pressure (MAP) sensor

- Start the engine and let rpm stabilize. Note vacuum level.

- Key "OFF".

- Remove vacuum gauge and tee and reconnect vacuum line to MAP sensor.

- Tee in vacuum gauge at a different source of intake manifold vacuum and restart the engine. Note vacuum level.

- Does the vacuum level differ more than 3.4 kPa (1.0 in-Hg)?

Yes -- Inspect engine vacuum integrity. Service as necessary. Remove vacuum gauge and Tee. Reconnect Heated Oxygen Sensor (HO2S). Drive vehicle 5 miles/55 mph. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Go to H30. H30 - HO2S Check