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Engine Speed Sensors

  1. Remove Gray (engine RPM) and Black (ignition timing reference) connectors from bracket near ignition coil. For each sensor connector, check continuity between terminals No. 1 and No. 2. See Fig 1 . Ohmmeter reading should be 1000 ohms.
  2. If not, replace sensor(s). If reading is correct, check continuity between terminals No. 1 and 3, and terminals No. 2 and 3 for each sensor connector. 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. SeeFigure and Fig 1 . Ensure resistance in each wire between ECU and sensor connectors is zero ohm. See the ENGINE SPEED SENSOR CIRCUITS  table.
ENGINE SPEED SENSOR CIRCUITS

Sensor Terminal ECU Terminal
Engine RPM (Gray)
1 29
2 11
3 28
Ignition Timing Reference (Black)
1 13
2 12
3 28
Fig 1: Engine Speed Sensor Connectors
G94331Courtesy of AUDI OF AMERICA, INC.