LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mitsubishi >> 2003 >> Eclipse GS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.4L >> Diagnostic Tests >> DTC P0102: Volume Air Flow (VAF) Circuit Low Input >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedure

CAUTION: To prevent damage to scan tool (MB991502), always turn the ignition off before connecting or disconnecting it.
  1. Connect scan tool (MB991502) to the data link connector. Start engine and run at idle. Set the scan tool to data reading mode for item 12, Volume Air Flow Sensor. Warm up the engine to normal operating temperature: 176-205°F (80-96°C). The standard value during idling should be 10 Hz or more. When the engine is revved, the frequency should increase according to the increase in engine speed. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, see INTERMITTENT DIAGNOSTIC TROUBLE CODES  . If the sensor is malfunctioning, go to the next step.
  2. Check the power supply voltage at volume air flow sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Turn the ignition on. Measure the voltage between terminal No. 4 and ground by backprobing. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, proceed to step  5 , otherwise, go to the next step.
  3. Check the power supply voltage at volume air flow sensor harness side connector B-14. Disconnect the connector B-14 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal No. 4 and ground. Voltage should be battery positive voltage. Turn the ignition off. If the voltage is normal, go to the next step. If the voltage is abnormal, repair harness wire between MFI relay connector A-18X terminal No. 4 and volume air flow sensor connector B-105 terminal No. 4 (because of open circuit or short circuit to ground) and proceed to step  13 .
  4. Check connector B-14 at the volume air flow sensor for damage. If the connector is in good condition, repair harness wire between MFI relay connector A-18X terminal No. 4 and volume air flow sensor connector B-14 terminal No. 4 (because of harness damage). If the connector is damaged, repair or replace it. Proceed to step  13 .
  5. Check connector B-14 at volume air flow sensor for damage. If the connector is in good condition, go to the next step. If the connector is damaged, repair or replace it and proceed to step  13 .
  6. Check the sensor supply voltage at volume air flow sensor harness side connector B-14. Disconnect the connector B-14 and measure at the harness side. Turn the ignition on. Measure the voltage between terminal No. 3 and ground. Voltage should be between 4.8-5.2 volts. Turn the ignition off. If the voltage is normal, proceed to step  9 , otherwise, continue with the next step.
  7. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. If the harness connector is in good condition, go to the next step. If the harness connector is damaged, repair or replace it and proceed to step  13 .
  8. Check for short circuit to ground between volume air flow sensor connector B-14 (terminal No. 3) and ECM connector C-60 (terminal No. 90 - M/T) or PCM connector C-54 (terminal No. 65 - A/T). If the harness wire is in good condition, replace the ECM or PCM. If the harness wire is damaged, repair it. Proceed to step  13 .
  9. Check the continuity at volume air flow sensor harness side connector B-14. Disconnect the connector B-14 and measure at the harness side. Check for the continuity between terminal No. 5 and ground. Resistance should be less than 2 ohm. If the continuity is normal, proceed to step  12 , otherwise, continue with the next step.
  10. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. If the connector is in good condition, go to the next step. If the connector is damaged, repair or replace it and proceed to step  13 .
  11. Check for open circuit and harness damage between volume air flow sensor connector B-14 (terminal No. 5) and ECM connector C-53 (terminal No. 40 - M/T) or PCM connector C-50 (terminal No. 16 - A/T). If the harness wire is in good condition, replace the ECM or PCM. If the harness wire is damaged, repair it. Proceed to step  13 .
  12. Check connector C-53 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. If the connector is in good condition, replace the volume air flow sensor. If the connector is damaged, repair or replace it. Go to the next step.
  13. Carry out a test drive with the drive cycle pattern, refer to OTHER MONITOR  . Check the diagnostic trouble codes. If DTC P0102 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.
scientia non olet · About LEMON Manuals