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Home >> Acura >> 1990 >> Integra LS, 2D Hatchback, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Code 3: Map Sensor
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Code 3: Map Sensor

NOTE: For wiring diagrams, see WIRING DIAGRAMS article. For vacuum diagrams, see VACUUM DIAGRAMS article.
  1. Turn ignition off. Remove hazard fuse at battery positive terminal for 10 seconds to reset ECU. Start engine and observe CHECK ENGINE light. If light is off, problem is intermittent. Check for poor or loose connections at MAP sensor and ECU. Test drive and check again.
  2. If light is on and Code 3 is present, turn ignition off. Disconnect 3-wire MAP sensor connector. Turn ignition on. Measure voltage between MAP sensor Yellow/Red (positive) wire and ground. If reading is not approximately 5 volts, repair open in Yellow/Red wire between ECU terminal C15 and MAP sensor.
  3. If wire is okay, substitute a known good ECU. If condition goes away, replace original ECU. If voltage is about 5 volts, measure voltage between Yellow/Red (positive) and Green/White (negative) wires. If approximately 5 volts is not present, repair open in Green/White wire between ECU terminal C14 and MAP sensor.
  4. If wire is okay, substitute a known good ECU and recheck. If voltage is now correct, replace original ECU. If voltage reading is about 5 volts after measuring between Yellow/Red and Green/White wires in step 3), measure voltage between White (positive) and Green/White (negative) wires.
  5. If voltage reading is not about 5 volts, repair open or short in White wire between ECU terminal C11 and MAP sensor. If wire is okay, substitute a know good ECU and recheck. If voltage is about 5 volts, turn ignition off. Reconnect MAP sensor connector.
  6. Connect ECU test harness between ECU and harness. Turn ignition on. Measure voltage between terminals C11 and C14 of ECU connector "C". If voltage is about 3 volts, substitute a known good ECU. If system functions properly, replace original ECU. If about 3 volts is not present, replace MAP sensor.
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