LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 1988 >> Integra SE, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Tests W/Codes >> Self-Diagnostic System >> Code 3 - Map Sensor
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Code 3 - Map Sensor

  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. 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 Red (pos.) wire and ground. If about 5 volts is present, go to step 3). If not, repair open in Red wire between ECU terminal C15 and MAP sensor. If wire is okay, substitute a known good ECU. If condition is rectified, replace original ECU.
  3. Measure voltage between Red (pos.) and Green/White (neg.) wires. If 5 volts is now present, go to step 4). If not, repair open in Brown/White wire between ECU terminal C14 and MAP sensor. If wire is okay, substitute a known good ECU. If specified voltage is now available, replace original ECU.
  4. Measure voltage between White (pos.) and Brown/White (neg.) terminals. If reading is about 5 volts, go to step 5). If not, repair open in White wire between ECU terminal C11 and MAP sensor. If wire is okay, substitute a known good ECU. If specified voltage is now available, replace original ECU.
  5. If measured voltage is about 5 volts, turn ignition off. Connect ECU test harness between ECU and ECU connector. Turn ignition off. Measure voltage between ECU terminals C11 (pos.) and C14 (neg.). See Figure . If there is not about 3 volts present, replace MAP sensor.
  6. If about 3 volts is present, substitute a known good ECU. If condition is rectified, replace original ECU.
scientia non olet · About LEMON Manuals