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Home >> Mitsubishi >> 2003 >> Lancer Evolution >> Repair and Diagnosis >> External Pages >> Different car >> Section 30 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0102: Mass Airflow Sensor Circuit Low Input Or DTC P0103: Mass Airflow Sensor Circuit High Input >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Nissan Maxima and 2002 Infiniti I35. However, it is still accessible from the selected car via links, so may be relevant.
  1. If DTC P0103 was duplicated, go to next step. If DTC P0102 was duplicated, check air intake duct and vacuum hoses for disconnection. If problem is found, repair as necessary. If problem is not found, go to next step.
  2. Turn ignition off. Loosen and retighten 2 engine ground bolts. See Figure . Disconnect MAF sensor harness connector. See Figure . Turn ignition on. Measure voltage between ground and MAF sensor harness connector terminals No. 2 (Red wire) and No. 4 (Red/Green wire). See Figure . About 5 volts should exist at terminal No. 2, and battery voltage should exist at terminal No. 4. If voltage is as specified, go to step  4 . If voltage is not as specified, go to next step.
  3. Check the following:
    • Check for poor connection at Black, 8-pin connector F18 terminal No. 7 (Red/Green wire). See Figure . Connector F18 is located on left side of engine compartment. See Figure or Figure .
    • Check for open or short between MAF sensor and ECM relay.
    • Check for open or short between MAF sensor and ECM.

    Repair as necessary.

  4. Turn ignition off. Disconnect ECM harness connector. See Figure . Check continuity of Black wire between MAF sensor harness connector terminal No. 3 and ECM harness connector terminal No. 80. See Figure . Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
  5. Check continuity of White wire between MAF sensor harness connector terminal No. 1 and ECM harness connector terminal No. 62. Also, check circuit for short to ground and short to voltage. If problem is found, repair as necessary. If problem is not found, go to next step.
    6. CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  6. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM terminal No. 62 (White wire) by backprobing, with engine at specified speeds. See MASS AIRFLOW SENSOR VOLTAGE  table under DIAGNOSTIC PROCEDURE under DTC P0101: MASS AIRFLOW SENSOR. If voltage is as specified, go to next step. If voltage is not as specified, disconnect and reconnect MAF sensor harness connector and repeat test. If voltage is still not as specified, replace MAF sensor.
  7. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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