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Home >> Honda >> 1990 >> Civic LX, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 1.5L TBI >> Trouble Code Tests - PGM-FI >> Code 5 - Map Sensor

Code 5 - Map Sensor

  1. Turn ignition off. Remove HAZARD fuse in main fuse box for 10 seconds to reset ECU. Start engine. Verify if CHECK ENGINE light is on and if LED is flashing Code 5. If LED is flashing Code 5, go to next step. If LED is not flashing Code 5, problem is intermittent. Check vacuum hoses, pipes and connections. Ensure all connectors are secure.
  2. Turn ignition off. Connect vacuum pump/gauge to MAP sensor hose at throttle body. Apply vacuum. If vacuum holds, go to step 3). If vacuum does not hold, attach vacuum pump/gauge directly to MAP sensor. Apply vacuum. If vacuum does not hold, replace MAP sensor. If vacuum holds, check MAP sensor vacuum hose for cracks, splits or looseness. Repair as necessary.
  3. Check vacuum supply to MAP sensor with engine running. If vacuum is not present, repair hose or clear restriction from throttle body. If vacuum supply is okay, turn ignition off. Connect ECU Test Harness between ECU and ECU connector. See Figure . Measure voltage between terminals C11 (positive) and C14 (negative). If voltage reading is about 3 volts, go to next step. If voltage is not about 3 volts, replace MAP sensor.
  4. Start engine and allow to idle. Measure voltage between terminals C11 (positive) and C14 (negative). If voltage is not about 1 volt, replace MAP sensor. If voltage reading is about 1 volt, Substitute a known good ECU and recheck. If condition is corrected, replace original ECU.
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