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Code 5: Manifold Air Pressure Sensor

  1. Turn ignition off. Remove alternator sense fuse in underhood relay box for 10 seconds to reset ECU. Start and idle engine, check for PGM-FI light. If light is off, test drive and check again.
  2. If light is on, remove #3 hose from the intake manifold and inspect the port for vacuum. If there is no vacuum, repair as necessary.
  3. If there is vacuum, connect a hand vacuum pump to #3 hose. Apply vacuum and check for leak. If vacuum is not maintained, replace #3 hose.
  4. If vacuum holds, stop engine. Connect the inspection adapter between MAP sensor and right side wire harness.
  5. Turn ignition on. Measure voltage between White terminal and Green terminal. If measurement is less than 3 volts, replace MAP sensor. If voltage is within specifications, substitute a known good ECU and recheck. If symptom/indication disappears, replace ECU.
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