LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Audi >> 1990 >> 100 Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Relays, Solenoids, Motors & Modules >> Cis Digital Control >> Oxygen Sensor Heating Element
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Oxygen Sensor Heating Element

  1. With engine cold, disconnect oxygen sensor heater connection. Connect ohmmeter between male terminals of sensor connector. Start engine and let idle. Resistance should be 2-4 ohms. If resistance is not as specified, replace oxygen sensor.
  2. Connect voltmeter between female terminals of oxygen sensor connector. Battery voltage should be present. If not, check continuity of wiring back to fuel pump relay.