LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Oldsmobile >> 1995 >> Aurora >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 4.0L >> ECM/Pcm Code Charts >> Code 56, Turbine Shaft Speed Sensor >> Notes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Code 56, Turbine Shaft Speed Sensor: Notes

Code will set if Codes 14, 75 and 91 are not set, transaxle is not in Park or Neutral, engine is running, vehicle speed is greater than 10 MPH, turbine speed is 50 RPM or less and all conditions have been present for 2 seconds.

NOTE: Test numbers refer to numbers on diagnostic chart.
  1. With engine idling in Park, turbine shaft speed should be within 100 RPM of engine speed.
  2. Sensor will generate greater than one volt with engine running. If no voltage is present, check sensor and high and low circuits for opens or short to ground.
  3. Checks sensor high and low circuits for opens and shorts to ground. If PCM terminals and circuitry are okay, PCM is faulty.
scientia non olet · About LEMON Manuals