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DTC P0100: Mass Airflow (MAF) Sensor: Procedure

  1. If malfunction "A" or "C" was duplicated, go to next step. If malfunction "B" or "D" was duplicated, inspect air intake duct and vacuum hoses for disconnection or leaks. Reconnect or repair as necessary and retest system. If no problems are found, go to next step.
  2. Turn ignition off. Loosen and retighten engine ground bolts located on intake manifold, near fuel injectors. Disconnect MAF sensor harness connector located near air cleaner. Turn ignition on. Measure voltage between MAF sensor harness connector terminal No. 3 (White/Red wire) and ground. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit. See WIRING DIAGRAMS article.
  3. Turn ignition off. Disconnect ECM harness connector. See Figure. Check continuity of Black/Red wire between MAF sensor harness connector terminal No. 2 and ECM harness connector terminal No. 48. See Figure. Also check circuit for short to voltage. Repair as necessary and retest system. If ground circuit is okay, go to next step.
  4. Check continuity of Brown wire between MAF sensor harness connector terminal No. 1 and ECM harness connector terminal No. 47. Also check circuit for short to ground and short to voltage. Repair as necessary and retest system. If circuit is okay, go to next step.
  5. Reconnect all harness connectors. Start engine and warm to normal operating temperature. Measure voltage between ground and ECM terminal No. 47 by backprobing, with engine at specified speeds. See Figure. See MASS AIRFLOW SENSOR VOLTAGE  table.
  6. If voltage is as specified, go to next step. If voltage is not as specified, disconnect and reconnect MAF sensor harness connector and repeat step  5. If voltage is still not as specified, replace MAF sensor and retest system. If voltage is now as specified, go to next step.
  7. No problem is indicated at this time. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
MASS AIRFLOW SENSOR VOLTAGE

Condition Volts
Key On, Engine Off Less Than 1.0
Engine Idling 1.2-1.5
2500 RPM 1.9-2.3
Idle To 4000 RPM (1) 1.2-1.5 To About 2.7
(1) Voltage should increase in proportion to engine speed.
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