What Is OBD Code P0717?
Code P0717 stands for “Input/Turbine Speed Sensor No Signal.” This diagnostic trouble code is triggered when your vehicle’s engine control module (ECM) or transmission control module (TCM) stops receiving a signal from the input speed sensor (also called the turbine speed sensor) for more than a specified duration. The input speed sensor monitors the rotational speed of the transmission’s input shaft and is critical for smooth gear shifting, torque converter lockup, and transmission performance.
What Does P0717 Mean?
The input/turbine speed sensor is a critical component that measures how fast the transmission’s input shaft is spinning. This information helps the transmission control module determine when to shift gears, engage the torque converter, and optimize fuel efficiency. When the TCM detects no signal from this sensor for a certain period, it sets code P0717.
This is different from a signal that’s intermittent or out of range—P0717 specifically means a complete loss of signal. The ECM/TCM uses this data to:
- Calculate transmission slip and torque converter efficiency
- Determine proper shift timing and pressure
- Monitor transmission health and detect problems
- Enable adaptive transmission learning
Without this signal, the transmission cannot operate optimally and may enter limp mode to prevent damage.
Common Symptoms of P0717
- Check Engine Light: Illuminates on the dashboard
- Transmission Limp Mode: Transmission stays in one gear (usually 3rd or 4th) to prevent damage
- Harsh or Delayed Shifting: Gear changes feel abrupt or take longer than normal
- Reduced Fuel Economy: Engine works harder without proper transmission optimization
- Transmission Overheating: Without proper shift control, transmission fluid heats up
- Difficulty Accelerating: Vehicle may feel sluggish or unresponsive
- No Overdrive: Transmission may not engage higher gears
- Transmission Shuddering: Vibration felt during acceleration or gear changes
Possible Causes (Ranked by Frequency)
1. Faulty Input Speed Sensor (Most Common)
The sensor itself may fail due to age, wear, or internal electrical failure. This is the most common cause of P0717. The sensor uses a magnetic pickup or Hall effect technology to detect shaft rotation, and these components can degrade over time.
2. Damaged Wiring or Connectors
Corrosion, loose connections, or damaged wires between the sensor and TCM prevent signal transmission. Road salt, moisture, and heat can degrade connectors in the transmission area.
3. Transmission Fluid Issues
Low or dirty transmission fluid can cause sensor malfunction. Contaminated fluid may also damage the sensor internally.
4. Sensor Gap or Alignment Problem
If the sensor is misaligned or the gap between the sensor and the reluctor ring is incorrect, the signal may be lost. This can occur after transmission work or sensor replacement.
5. Reluctor Ring Damage
The reluctor ring (tone ring) that the sensor reads may be damaged, cracked, or missing teeth. This prevents the sensor from detecting shaft rotation.
6. Transmission Control Module (TCM) Failure
In rare cases, the TCM itself may fail or have a faulty input circuit, preventing it from receiving the sensor signal even if the sensor is working correctly.
7. Wiring Harness Issues
A pinched, cut, or burned wire in the transmission wiring harness can interrupt the sensor signal path.
Diagnostic Steps
Step 1: Scan for Additional Codes
Use an OBD-II scanner to check for other transmission-related codes. Codes like P0716 (Input Speed Sensor Range/Performance) or P0720 (Output Speed Sensor) can provide additional diagnostic clues.
Step 2: Inspect Wiring and Connectors
Locate the input speed sensor connector (typically on or near the transmission). Check for:
- Corrosion or green/white deposits on connector pins
- Loose or damaged connector housing
- Visible wire damage or pinching
- Water intrusion or moisture inside the connector
Clean corroded connectors with electrical contact cleaner and reseat firmly.
Step 3: Check Transmission Fluid Level and Condition
Low or burnt-smelling transmission fluid can cause sensor issues. Check the level with the engine running and transmission in Park. Fluid should be bright red and not smell burnt. If low, top up and retest.
Step 4: Test the Sensor with a Multimeter
With the engine off, disconnect the sensor connector and use a multimeter to check resistance. Compare readings to manufacturer specifications (typically 200-900 ohms for most sensors). Out-of-spec readings indicate a faulty sensor.
Step 5: Check Sensor Gap and Alignment
If the sensor is accessible, measure the gap between the sensor tip and the reluctor ring. Typical gap is 0.020-0.050 inches. If the gap is too large or the sensor is misaligned, reposition or replace it.
Step 6: Inspect the Reluctor Ring
If the transmission pan must be dropped for sensor access, visually inspect the reluctor ring for cracks, missing teeth, or damage. A damaged reluctor ring requires transmission disassembly to replace.
Step 7: Test with a Scope (Advanced)
A skilled technician can use an oscilloscope to monitor the sensor signal while the engine runs. A healthy signal should show a clean waveform that increases in frequency as engine RPM increases. No signal or a distorted waveform confirms a problem.
Repair Cost Estimates
Sensor Replacement: $150–$400 (parts + labor)
- Sensor part cost: $50–$150
- Labor: 1–3 hours depending on transmission type and accessibility
Wiring/Connector Repair: $100–$300
- If only wiring or connector cleaning/repair is needed
Transmission Fluid Service: $150–$300
- If fluid change resolves the issue
Reluctor Ring Replacement: $500–$1,500+
- Requires partial transmission disassembly
- Labor-intensive repair
TCM Replacement (Rare): $800–$2,000+
- Only if module is confirmed faulty
- May require programming/calibration
Note: Costs vary significantly by vehicle make, model, and year. Luxury and newer vehicles typically cost more. Always get a diagnostic before authorizing repairs.
Can I Still Drive With Code P0717?
Severity: Moderate to High
While you may be able to drive short distances, it’s not recommended for extended periods. Here’s why:
- Limp Mode: Your transmission will likely stay in one gear, limiting performance and fuel economy
- Transmission Overheating: Without proper shift control, fluid temperature rises, risking transmission damage
- Reduced Safety: Limited acceleration and gear selection can be dangerous in traffic or emergency situations
- Potential Damage: Prolonged driving in limp mode can cause internal transmission wear and failure
- Warranty Issues: Continuing to drive with this code may void transmission warranty coverage
Recommendation: Have the code diagnosed and repaired as soon as possible. If you must drive the vehicle, keep speeds low and avoid highway driving. Do not tow anything until the issue is resolved.
Frequently Asked Questions
Q: Can a bad battery cause code P0717?
A: Indirectly, yes. A weak battery may cause voltage fluctuations that disrupt the sensor signal or TCM operation. However, a truly bad sensor or wiring issue is more common. If you recently had battery work done, have the sensor connector and wiring inspected for damage.
Q: Will clearing the code fix the problem?
A: No. Clearing the code without fixing the underlying problem will only cause it to reappear. The code is a symptom, not the cause. You must diagnose and repair the faulty sensor, wiring, or related component.
Q: Is code P0717 the same as P0716?
A: No. P0717 means no signal is being received at all. P0716 (Input Speed Sensor Range/Performance) means the signal exists but is out of the expected range or not changing as expected. P0716 often indicates a sensor that’s working but giving incorrect readings, while P0717 indicates a complete signal loss.
Q: How much does it cost to replace an input speed sensor?
A: Typically $150–$400 for parts and labor combined. The sensor itself costs $50–$150, and labor ranges from 1–3 hours depending on accessibility. Some transmissions require pan removal, which increases labor costs. Luxury vehicles and newer models may cost significantly more.
Q: Can I replace the sensor myself?
A: It depends on your vehicle and the sensor’s location. Some input speed sensors are easily accessible and can be replaced by a DIYer with basic tools. Others require transmission pan removal or special knowledge. If you’re not confident, have a professional handle it to avoid damaging the transmission.
Q: What vehicles commonly have P0717 issues?
A: Dodge Caravans, Chrysler 300s, and Jeep Liberties are frequently reported, but this code can occur on any vehicle with an automatic transmission. Chrysler/Dodge/Jeep vehicles with 4-speed and 5-speed automatic transmissions are particularly prone to this issue.