DF13

- Key "OFF".

- Tee a vacuum gauge in the intake manifold vacuum supply hose at the Manifold Absolute Pressure (MAP) sensor.

- Perform Key On Engine Running (KOER) Self-Test while observing vacuum.

- Did vacuum decrease by more than 34 kPa (10 in Hg) vacuum during Dynamic Response test?

Yes -- Replace MAP sensor. Remove vacuum gauge. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Electronic Engine Controls (EEC) system OK. Refer to Engine Section for probable causes affecting engine vacuum.