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Code 5, Map Sensor

  1. Turn off ignition. Remove "EFI/ECU" fuse in under-hood relay panel for 10 seconds to reset ECU. Start engine and hold at idle. Check if warning light is on. If not on, problem is inter-mittent. Test drive and check light again.
  2. If light is on, turn ignition off. Using a "T" fitting, connect a hand-held vacuum pump/gauge into vacuum hose between throttle body and MAP sensor (located inside control box). Start engine. If vacuum is not present, repair as necessary. If vacuum is present and holds, turn ignition off.
  3. Connect vacuum pump to MAP sensor and apply vacuum. If vacuum does not hold, replace MAP sensor. Also check vacuum hose for leaks or blockage. If vacuum does hold, turn ignition off. Connect test harness 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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