Input/Turbine Speed Sensor Circuit No Signal
The P0717 code indicates that the Powertrain Control Module (PCM) or Transmission Control Module (TCM) is not receiving a signal from the transmission input/turbine speed sensor. The module sets this code when it detects zero RPM from the sensor while the engine is running and the vehicle is in motion, preventing proper shift calculations.
This code is moderately urgent because the lack of input speed data often forces the transmission into a fail-safe or 'limp' mode. Driving in this condition for extended periods can cause poor performance and potential internal transmission wear.
Common symptoms
- Illuminated Check Engine Light
- Harsh or erratic transmission shifting
- Transmission slipping or failure to shift gears
- Vehicle stuck in 'limp mode' (fail-safe mode)
- Decreased fuel efficiency and poor acceleration
Likely causes
- Defective input/turbine speed sensor
- Damaged, corroded, or loose wiring and connectors in the sensor circuit
- Metal debris accumulation on the sensor's magnetic tip
- Dirty or severely contaminated transmission fluid
- Faulty Transmission Control Module (TCM) or PCM (rare)
What to check before replacing parts
Check the transmission fluid level and condition
Look for: Look for low fluid levels, a burnt smell, or heavy metal contamination in the fluid that could interfere with the sensor's magnetic operation.
Visually inspect the wiring and connectors for the input speed sensor
Look for: Look for frayed wires, melted insulation, or corroded pins at the sensor connector that would cause an open circuit.
Monitor live data using an OBD-II scan tool
Look for: Observe the input/turbine speed PID while the engine is running and the vehicle is in gear; a constant reading of 0 RPM confirms the lack of signal.
Remove and physically inspect the input speed sensor
Look for: Look for metal shavings or debris accumulated on the magnetic tip of the sensor that could block the signal from the reluctor wheel.
Test the sensor resistance and circuit continuity with a multimeter
Look for: Verify the sensor's internal resistance matches factory specifications and that there is continuity (no open or short circuits) between the sensor connector and the TCM/PCM.
This page explains the generic P0717 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
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