LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Volkswagen >> 1987 >> Quantum Base, Standard >> Repair and Diagnosis >> Engine Performance >> Ignition System - BOSCH Hall Effect >> Testing >> Knock Sensor Control Unit >> Continuity & Resistance Tests (Volkswagen GLI & GTI)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Continuity & Resistance Tests (Volkswagen GLI & GTI)

  1. With ignition off, disconnect knock sensor control unit. Connect voltmeter negative lead to terminal No. 3 and positive lead to terminal No. 5 at connector. Turn ignition on.
  2. Meter should indicate battery voltage. If no voltage is present, check fuse No. 18 on fuse block. If okay, check ground connection at intake manifold. Check wire No. 5 to ignition switch.
  3. Connect voltmeter negative lead to terminal No. 3 and positive lead to terminal No. 8 at connector. Turn ignition on. Actuate full throttle switch. Meter should indicate battery voltage.
  4. If no voltage is present, voltage supply (center wire) to throttle switch is open. If not, full throttle switch is defective. Replace full throttle switch.
  5. Connect voltmeter negative lead to terminal No. 3 and positive lead to terminal No. 6 at connector. Turn ignition on. Meter should indicate battery voltage. If no voltage is present, wire to idle switch is open. If not, idle switch is improperly adjusted and/or defective.
  6. Connect voltmeter negative lead to terminal No. 3 and positive lead to terminal No. 10 at connector. Turn ignition on. Meter should indicate battery voltage. If no voltage is present, wire to fuel pump relay is open. Repair wire as necessary.
  7. Turn ignition off. Connect ohmmeter between connector terminals No. 2 and 3. Ensure CIS-E fuel control unit is connected. Ohmmeter reading must be 90,000-100,000 ohms. If reading is incorrect, wire No. 2 to CIS-E control unit is open. If not, CIS-E control unit is defective.
  8. Connect ohmmeter between connector terminals No. 3 and 4. Connect test connector in engine compartment to ground. Ohmmeter should indicate continuity to ground.
  9. Connect ohmmeter between connector terminals No. 3 and 11. Ohmmeter should indicate continuity. If no continuity is indicated, ground wire between terminals No. 3 and 11 is open. On some models terminal No. 11 may not be used.
  10. Connect ohmmeter between connector terminals No. 3 and 12. Disconnect Hall control unit and install a jumper wire between terminals No. 2 and 6. Ohmmeter should indicate continuity.
  11. Connect ohmmeter between connector terminals No. 3 and 13. Ohmmeter should indicate one milliohm. If reading is incorrect, wires to knock sensor are open or knock sensor is defective.
  12. Connect ohmmeter between connector terminals No. 13 and 14 to measure the resistance of the knock sensor. Ohmmeter should indicate approximately 300,000 ohms for a type I sensor and approximately infinity for a type II sensor. If reading is incorrect, wires to knock sensor are open or knock sensor is defective.
  13. Connect ohmmeter between connector terminals No. 7 and 15. Disconnect Hall Effect sending unit and install a jumper wire between terminals No. 1 and 3. Ohmmeter should indicate continuity.
  14. Connect ohmmeter between connector terminals No. 7 and 9. Disconnect Hall Effect sending unit and install a jumper wire between middle terminal (Green/Purple wire) and outer terminal (Brown/White wire). Ohmmeter should indicate continuity.
scientia non olet · About LEMON Manuals