1989 Audi 80 Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Engine Speed Sensors

  1. Remove Gray (engine RPM) and Black (ignition timing reference) connectors from bracket near ignition coil. Connect ohmmeter to each sensor connector terminals No. 1 and 2. See Fig 2 . Ohmmeter reading should be 1000 ohms.
  2. If not, replace sensor(s). If reading is correct, check continuity between each sensor connector terminals No. 1 and 3, and 2 and 3. If ohmmeter reading is not infinity (4), replace sensor(s).
  3. Unplug connector from ECU. Check wiring between harness side of each sensor connector and ECU. SeeFig 1 and Fig 2 . Ensure each wire between ECU and sensor connectors has zero ohms of resistance. See ENGINE SPEED SENSOR CIRCUITS  chart.
    ENGINE SPEED SENSOR CIRCUITS

    Sensor Terminal Connector Terminal
    Engine RPM (Gray)
    1 29
    2 11
    3 28
    Ignition Timing Reference (Black)
    1 13
    2 12
    3 28
  4. Ensure clearance between ignition timing reference sensor and flywheel pin is .43" (1.10 mm) If engine speed sensors and wiring circuits are okay, replace control unit.
Fig 1: View of ECM Harness Connector
G94330Courtesy of AUDI OF AMERICA, INC.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.