LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Audi >> 1990 >> 90 Quattro >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Testing >> Ignition Checks >> Cis Digital Control >> Hall Effect Sending Unit
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Hall Effect Sending Unit

  1. Remove protective cover from Hall Effect sending unit (on distributor) and unplug 3-wire connector from unit. Connect voltmeter to connector terminals No. 1 and 3. Turn ignition on. Voltmeter reading should be 9 volts minimum.
  2. If reading is not as specified, check for open circuit in wiring between sending unit and ECU terminals No. 23 and 25. See Figure for ECU terminal identifications. If reading is as specified, turn ignition off. Move back connector cover to gain access to rear of 3-wire connector. Reinstall 3-wire connector to distributor Hall sending unit. Connect voltmeter between terminals No. 1 and 2 at rear of 3-wire connector.
  3. Remove distributor cap, rotor and dust cover. Turn crankshaft by hand until rotor window clears sending unit. Turn ignition on. Voltmeter should read minimum of 4 volts.
  4. Turn crankshaft until rotor window fully aligns with sending unit. Voltmeter should read 0-.5 volt. Turn ignition off. If readings are not as specified, replace Hall Effect sending unit. If readings are as specified, check wiring between Hall Effect sending unit and ECU for shorts or opens in wires and repair as necessary. If circuits are okay, replace ECU.
scientia non olet · About LEMON Manuals