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Home >> Toyota >> 1995 >> Pickup Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 2.4L >> Diagnostic Testing >> Code 31 - Volume Airflow (VAF) Sensor Circuit >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. Access ECM behind right kick panel. Using DVOM, backprobe ECM connector. Turn ignition on. Measure voltage between terminal VC and ground. See Figure, Figure and Figure. Voltage should be 6-10 volts.
  2. Measure voltage between terminal VS and ground. Voltage should be .2-2.5 volts. Remove air intake hose at VAF meter. Carefully fully open air door. Voltage should be 5-10 volts.
  3. If all voltages measured are within specification, go to next step. If any voltage is NOT within specification, inspect circuit for open or short. See wiring diagram in WIRING DIAGRAMS - 2.4L article. Repair as needed.
  4. Inspect VAF meter. See SYSTEM/COMPONENT TESTS - 2.4L article. Replace as needed. If VAF meter is okay, replace ECM and retest.
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