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Home >> Honda >> 1985 >> Prelude Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Feedback Carburetor System >> Trouble Shooting >> Speed Sensor
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Speed Sensor

  1. Jack up and support the front of vehicle. Push the voltmeter or test light positive probe into the Yellow/Black wire terminal at the control unit connector.
  2. Connect the negative probe to ground. Start engine. Place vehicle in 2nd gear and accelerate slowly. Battery voltage should be as shown in table.
    SPEED SENSOR VOLTAGE CHECK

    Speed Voltage
    Below 11 MPH Yes
    Above 16 MPH No
  3. If voltage does not correspond to above MPH ranges, install a new speed sensor and retest. If there was no voltage during step 2), check for bad electrical connection, fuse or faulty speed sensor. Replace or repair as necessary and retest.