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Code 3 - Map Sensor

  1. Turn ignition off. Remove appropriate fuse for 10 seconds to reset ECU. See CLEARING CODES  . Start engine, and warm to normal operating temperature (cooling fan comes on). Verify if CHECK ENGINE light is on and if LED is flashing Code 3. If Code 3 is present, go to next step. If Code 3 is not present, problem is intermittent. Check connectors at MAP sensor and at ECU.
  2. Turn ignition off. Disconnect 3-wire connector from MAP sensor. Turn ignition on. Measure voltage between Red/White (+) wire and ground. If reading is about 5 volts, go to step 3). If reading is not about 5 volts, go to step 7).
  3. Measure voltage between Red/White (+) and Blue/White (-) wires. If about 5 volts are present, go to step 4). If about 5 volts are not present, repair open in Blue/White wire between ECU terminal D21 (C14 on 2.0L) and MAP sensor. If wire is okay, substitute a known good ECU. If condition is corrected, replace original ECU.
  4. Measure voltage between White/Blue (+) and Blue/White (-) wires. If voltage is about 5 volts, go to step 5). If about 5 volts are not present, repair open in White/Blue wire between ECU terminal D17 (C11 on 2.0L) and MAP sensor. If wire is okay, substitute a known good ECU. If condition is corrected, replace original ECU.
  5. Turn ignition off. Reconnect 3-wire connector to MAP sensor. Connect appropriate ECU test harness between ECU and ECU harness. See Figure and Figure . Turn ignition on. Measure voltage between terminals D17 and D21 (C11 and C14 on 2.0L). See Figure and Figure .
  6. If reading is not about 3 volts, replace MAP sensor. If about 3 volts are present, substitute a known good ECU, and recheck. If condition is corrected, replace original ECU.
  7. Connect ECU Test Harness to ECU only. Measure voltage between ECU terminals D19 and D21 (C15 and C14 on 2.0L). If about 5 volts are present, repair open in Red/White wire between ECU terminal D19 (C15 on 2.0L) and MAP sensor. If about 5 volts are not present, substitute a known good ECU, and retest. If condition is corrected, replace original ECU.
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