LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Isuzu >> 1990 >> Impulse Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests - EFI >> Sensors >> Oxygen (O2) Sensor Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Oxygen (O2) Sensor Test

  1. Start engine and warm to operating temperature. Ensure vehicle is operating in closed loop. Unplug O[I2] sensor connector at sensor.
  2. Using Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, connect DVOM (on voltmeter scale) between ground and oxygen sensor connector (sensor side).
  3. Place a short jumper wire in sensor lead (computer side). While holding jumper wire in one hand, alternately touch negative battery terminal and then positive terminal with other hand. DO NOT TOUCH sensor lead directly to battery.
  4. Monitor DVOM reading. When negative battery terminal is touched, oxygen sensor output voltage should increase (up to one volt). When positive battery terminal is touched, oxygen sensor output voltage should drop (as low as .1 volt). If oxygen sensor does not respond as indicated, replace sensor.
scientia non olet · About LEMON Manuals