LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mitsubishi >> 2002 >> Eclipse GS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self Diagnostics - 2.4L >> Diagnostic Tests >> DTC P0101: Volume Air Flow (VAF) Circuit Range/Performance Problem >> 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 the scan tool.
  1. Connect Scan Tool (MB991502) to the data link connector. Start the 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, refer to INTERMITTENT DIAGNOSTIC TROUBLE CODES . If the sensor is malfunctioning, go to next step.
  2. Check the reset signal voltage at volume air flow sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Turn on the ignition. Measure the voltage between terminal 7 and ground by backprobing. See Figure. Voltage should be between 6.0-9.0 volts. Turn the ignition off. If the voltage is normal, go to step  5, otherwise, go to next step.
  3. Check connector B-14 at volume air flow sensor and connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. See Figure or Figure . If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step  9.
  4. Check for short circuit to ground between volume air flow sensor connector B-14, terminal 7 and ECM connector C-49, terminal 19 (M/T) or PCM connector C-50, terminal 19 (A/T). If the harness wire is in good condition, replace the volume air flow sensor and go to step  9, otherwise, repair it and go to step  9.
  5. Check the reset signal voltage at volume air flow sensor connector B-14 by backprobing. Do not disconnect the connector B-14. Start the engine and run at idle. Measure the voltage between terminal 7 and ground by backprobing. See Figure. When the engine is idling, voltage should be 1.0 volt or less. When the engine speed is 3000 RPM, voltage should be between 6.0-9.0 volts. Turn the ignition off. If the voltage is normal, go to step  8, otherwise, go to next step.
  6. Check connector B-14 at volume air flow sensor and connector C-49 at ECM (M/T) or connector C-50 at PCM (A/T) for damage. If the connector is in good condition, go to next step, otherwise, repair or replace it and go to step  9.
  7. Check for open circuit and harness damage between volume air flow sensor connector B-105, terminal 7 and ECM connector C-49, terminal 19 (M/T) or PCM connector C-50, terminal 19 (A/T). If the harness wire is in good condition, replace the ECM or PCM and go to step  9, otherwise, repair it and go to step  9.
  8. Replace the volume air flow sensor. Carry out a test drive with the drive cycle pattern. Check the diagnostic trouble codes. If DTC P0101 is output, replace the ECM or PCM and go to next step. If the DTC is absent, the inspection is complete.
  9. Carry out a test with the drive cycle pattern, refer to OTHER MONITOR . Check the diagnostic trouble codes. If DTC P0101 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.
scientia non olet · About LEMON Manuals