P0717
UniversalInput/Turbine Speed Sensor Circuit No Signal
Medium SeverityThe P0717 code indicates that the vehicle's powertrain control module (PCM) or transmission control module (TCM) is not receiving a signal from the input/turbine speed sensor. This sensor is crucial for the transmission to determine the rotational speed of its input shaft, which is necessary for proper gear shifting and transmission operation. Without this signal, the transmission may experience erratic shifts, incorrect gear engagement, or may enter a limp-home mode, severely affecting driveability.
⚠️ Before You Begin (Safety First)
Always ensure the vehicle is safely parked on a level surface with the parking brake engaged before attempting any repairs. Allow the engine and transmission to cool down completely to avoid burns from hot fluids or components. Disconnect the negative battery terminal before working on electrical components to prevent accidental shorts or injury. Use appropriate safety gear, including gloves and eye protection.
Common Symptoms
- Check Engine Light (MIL) illuminated
- Erratic or harsh shifting
- Transmission stuck in one gear (limp mode)
- Transmission not shifting at all
- Speedometer or tachometer erratic
- Vehicle hesitates or stumbles during acceleration
Common Causes
- Faulty input/turbine speed sensor
- Damaged or corroded wiring to the sensor
- Loose or corroded sensor connector
- Short circuit in the sensor circuit
- Open circuit in the sensor circuit
- Failure of the powertrain control module (PCM) or transmission control module (TCM) (rare)
Frequently reported on: General/Universal
Diagnostic Steps
- Inspect Wiring and Connector: Locate the input/turbine speed sensor on your transmission (consult a repair manual for exact location). Visually inspect the sensor's electrical connector for corrosion, bent pins, or a loose fit. Check the wiring harness leading to the sensor for any signs of fraying, cuts, or damage.
- Clear Code and Test Drive: If wiring and connector appear good, clear the P0717 code using an OBD-II scanner. Take the vehicle for a short test drive to see if the code returns. Sometimes, a temporary glitch can trigger the code.
- Test Sensor Resistance (if applicable): Some input/turbine speed sensors can be tested for resistance using a multimeter. Refer to your vehicle's service manual for the correct specifications and procedure. An out-of-spec reading indicates a faulty sensor.
- Replace Input/Turbine Speed Sensor: If the sensor is determined to be faulty or if the code consistently returns after inspections, replace the sensor. This usually involves unbolting the old sensor and installing the new one. You may lose some transmission fluid during this process, so be prepared to top it off if necessary.
- Clear Code and Final Test Drive: After replacement, clear the code again and perform an extended test drive to confirm the repair and ensure the transmission is shifting correctly.
👨🔧 When to Call a Professional
While replacing the input/turbine speed sensor is often a straightforward DIY task, if the code persists after sensor replacement and wiring inspection, or if you notice severe transmission issues like grinding or slipping, it is crucial to consult a professional mechanic. This could indicate a deeper electrical problem or internal transmission damage that requires specialized diagnostic tools and expertise.
Commonly Asked Questions
What does the input/turbine speed sensor do?
The input/turbine speed sensor monitors the rotational speed of the transmission's input shaft, which helps the vehicle's computer determine engine load and select the appropriate gear for smooth and efficient shifting.
Can I drive my car with a P0717 code?
It is not recommended to drive for extended periods with a P0717 code. While the vehicle might still move, the transmission will likely not shift properly, which can lead to further damage to the transmission or create unsafe driving conditions.
Is replacing the input/turbine speed sensor difficult?
Replacing the sensor is often considered a medium difficulty DIY task. It usually requires getting under the vehicle and may involve some minor fluid loss, but it typically doesn't require specialized tools beyond basic wrenches and sockets.
What's the difference between an input speed sensor and an output speed sensor?
The input speed sensor measures the speed of the transmission shaft directly connected to the engine, while the output speed sensor measures the speed of the shaft connected to the wheels. Both are crucial for the transmission's gear ratio calculations.
Could a P0717 code indicate a more serious transmission problem?
While P0717 most commonly points to the sensor or its wiring, if the problem persists after replacing the sensor and checking wiring, it could indicate an issue with the transmission's valve body, internal components, or even the control module itself. In such cases, professional diagnosis is recommended.