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Code 5, Map Sensor

  1. Turn ignition off and disconnect alternator sense fuse in under-hood relay box for 10 seconds to reset ECU. Start engine and observe PGM-FI warning light. If light is off, problem is intermittent. Test drive and check again.
  2. If light is on, turn ignition off. Using a "T" fitting, connect a hand-held vacuum pump/gauge in the No. 4 vacuum hose from vacuum manifold. Start engine. If vacuum is not present, repair as necessary. If vacuum is present and holds, turn ignition off.
  3. Connect inspection adaptor between MAP sensor and harness. Turn ignition on. Measure voltage between White (pos.) terminal and Green (neg.) terminal. If reading is not about 3 volts, replace MAP sensor. If voltage reading is about 3 volts, substitute a known good ECU. If condition is rectified, replace original ECU.
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