P0717 on 2016-2021 Honda Civic: Input Speed Sensor Failure Causes and Fixes

What's Unique About the 2016-2021 Honda Civic

The 10th generation (2016-2021) Civic predominantly uses a CVT. Unlike traditional automatic transmissions, the CVT relies heavily on a constant stream of data from both an input (drive pulley) and a turbine speed sensor to make seamless ratio adjustments. The TCM compares these two speeds to ensure the transmission is operating correctly. When the primary input signal is lost (P0717), the TCM has no reference for the transmission's input speed, causing it to immediately trigger a fail-safe or 'limp mode' to prevent potential damage. The fault is almost always electrical and not an internal mechanical failure of the CVT itself, a common misdiagnosis that could lead to a costly and unnecessary transmission replacement.

Symptoms You May Notice

• Check Engine Light is on
• Blinking 'D' (Drive) indicator light on the dashboard
• Transmission enters 'limp mode,' often stuck in one ratio and unable to accelerate properly
• Harsh or delayed engagement ('banging' into gear) when shifting from Park to Drive or Reverse
• Vehicle feels sluggish and has poor acceleration
• Reduced fuel economy

Most Likely Causes

1. Faulty Input/Turbine Speed Sensor 'A' 🔴 High Probability The sensor is an electronic component that can fail over time due to heat cycles and vibration. It is the most common point of failure for a 'no signal' circuit code, as confirmed by numerous owner experiences.
   How to confirm: After verifying the wiring is intact, the sensor itself is the culprit. A diagnostic tool will show 0 RPM from the input sensor even when the vehicle is moving. Testing the sensor's connector for correct voltages is the definitive test; if power and ground are good but the signal is absent, the sensor has failed.
   Typical fix: Replace the input/turbine speed sensor. This sensor is located on the exterior of the transmission case, typically under the air intake box assembly.
   Est. part cost: $50-$150
2. Damaged Wiring or Loose Connector 🟡 Medium Probability The wiring harness leading to the transmission can be exposed to heat, vibration, or rodent damage, potentially causing wires to break or the connector to become loose or corroded over time.
   How to confirm: Visually inspect the wiring harness leading to the input speed sensor for any signs of damage, melting, or corrosion. Disconnect the connector and check for clean, tight-fitting pins. Use a multimeter to check for voltage at the connector with the key on.
   Typical fix: Repair the damaged section of the wire or clean/replace the connector.
   Est. part cost: $5-$50

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM) or Transmission Control Module (TCM): This is very rare. Before condemning the control module, all other possibilities, including the sensor and its entire circuit, must be exhaustively tested. A faulty module may also be accompanied by other seemingly unrelated trouble codes.

Diagnosis Steps

1. Read the code with an OBD-II scanner to confirm P0717 is present.
2. Check the transmission fluid level and condition. While not a direct cause of a 'no signal' code, low or burnt fluid indicates other potential issues that should be addressed.
3. Locate the input/turbine speed sensor on the transmission housing. On the 10th gen Civic, this requires removing the air filter box and intake tubing. The sensor has a blue or gray electrical connector.
4. Inspect the sensor's electrical connector and wiring harness for any visible damage, corrosion, or loose connections.
5. With the key in the 'ON' position (engine off), disconnect the sensor. Use a multimeter to test the terminals in the harness-side connector. On a typical 3-wire sensor, you should find one ground wire (close to 0V) and two wires showing a 5-volt reference from the PCM.
6. If two 5V reference signals and a good ground are present, the wiring from the TCM to the connector is good, and the sensor itself has failed.
7. If voltage or ground is missing, there is an open or short in the wiring harness between the TCM and the sensor that must be traced and repaired.
8. If the wiring is confirmed to be good, replace the input/turbine speed sensor. Always use a new O-ring and apply a small amount of clean transmission fluid to it before installation.
9. After replacement, clear the DTC with the scanner and perform a test drive. You must drive the vehicle over 19 mph (30 km/h) for the system to verify the repair and confirm the fix.

Parts You'll Likely Need

• Transmission Input Speed Sensor (Turbine Speed Sensor) (OEM #28810-5DJ-004) — This sensor is the most common failure point for a P0717 code, as it provides the direct input speed reading to the TCM.
  Trusted brands: Honda (Genuine OEM), NTK, Beck/Arnley, Standard Motor Products
  OEM price range: $100-$150
  Aftermarket price range: $50-$120

Platform-Specific Known Issues

• Owner Confusion Between Input and Output Sensors: A user on Reddit posted a picture of two different sensors they removed from their 2016 Civic's transmission while trying to fix a P0717 code. The community confirmed that the longer sensor, found under the airbox, was the correct input speed sensor, while the shorter sensor was the output/vehicle speed sensor. This highlights the importance of correctly identifying the sensor before replacement.

Mechanic-Grade Diagnostic Values

• Voltage between sensor connector pin 2 and body ground — expected: Approximately 5V. Failure: A reading other than ~5V suggests a fault in the signal circuit wiring or TCM.
• Voltage between sensor connector pin 3 and body ground — expected: Approximately 5V. Failure: A reading other than ~5V suggests an open in the VCC2 power wire from the TCM.
• Voltage between sensor connector pin 1 and pin 3 — expected: Approximately 5V. Failure: If power and ground are confirmed good at the connector, but this test fails, the sensor itself is defective.

Scan Tool Commands That Help

• Honda Diagnostic System (HDS) or equivalent: Clear DTCs — After replacing the sensor, the code must be cleared. No specific relearn or adaptation is required for the sensor itself, but a test drive is necessary to confirm the fix.

Wiring & Ground Locations

• Transmission Ground Cable — A cable connecting the transmission case to the chassis.. A poor ground connection can cause a variety of electrical issues, including sensor signal problems. While not the most common cause for P0717, ensuring the ground is secure and free of corrosion is a valid diagnostic step. The OEM part number for the cable is 32601-TBA-A00.
• Input/Turbine Speed Sensor 3P Connector — On the top of the transmission, under the air intake assembly.. This is the connector where all diagnostic voltage tests are performed to determine if the fault lies in the sensor, the wiring harness, or the control module.

Real Owner Repair Stories

• YouTube Commenter (Honda Accord (similar platform)) — Hard shift into Drive/Reverse, flashing D light, Check Engine Light with P0717.
  ❌ Tried (didn't work) An initial replacement of the sensor did not fix the problem.
  ✅ What actually fixed it The owner discovered they had not fully seated the new sensor into the transmission housing. After removing it and pushing it all the way in until it was flush before tightening the bolt, the problem was resolved. This highlights a common DIY mistake.
• Honda Owner Report — An owner of a similar Honda platform reported a message on the car stating "engine system problem" and advising not to drive the vehicle. A diagnostic scan revealed DTC P0717 for Input/Turbine Speed Sensor A Circuit No Signal (NHTSA ODI #11646484).

OEM Part Supersession History

• 28810-5DJ-004 → No supersession found.
  Heads up: This part number appears to be consistent for the 2016-2021 Honda Civic model years.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• A/C Condenser Failure 🔴 High — Very common across all 2016-2021 models. The condenser was manufactured to poor specifications, leading to tiny holes and refrigerant leaks. (Ref: Honda issued a warranty extension (TSB 19-091) covering the A/C condenser for 10 years with unlimited mileage for factory defects. A separate TSB (23-039) addresses A/C compressor shaft seal leaks.)
• Engine Oil Dilution (1.5L Turbo) 🟠 Medium — Common on 1.5L turbo models, especially in cold climates or with frequent short trips. Fuel mixes with engine oil, reducing lubrication. (Ref: Honda addressed this with software updates for the ECU and TCM under TSB A19-033 to help the engine warm up faster. Owners often report an oil level over the full mark with a strong smell of gasoline.)
• Sticky Steering at Highway Speeds 🔴 High — Affects some later models in this generation and is more prominent on the 11th gen. The steering can feel momentarily 'stuck' or require extra effort to turn off-center. (Ref: Honda TSB 23-037 was issued, instructing dealers to replace the electronic power steering (EPS) gearbox. The issue is caused by a manufacturing defect in the worm gear.)
• CVT Torque Converter Shudder 🟠 Medium — Prevalent in earlier years (2016-2018), typically appearing between 30,000 and 80,000 miles. It's felt as a vibration during light acceleration. (Ref: Honda addressed this with updated CVT fluid (HCF-2) and software updates. No single TSB is universally cited, but dealers are aware of the issue.)

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: Given the relatively low cost of a new aftermarket or OEM sensor ($50-$150) and the labor involved in accessing it, using a used sensor from a junkyard is generally not recommended. The electronic component's remaining lifespan is unknown, and the risk of premature failure outweighs the small cost savings.

Donor-vehicle mileage cap: roughly under 50000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Check for physical damage to the sensor body and connector.
• Ensure the O-ring is present and not degraded (though it should always be replaced with a new one).
• Avoid sensors with heavy corrosion on the electrical pins.

OEM-only on this vehicle (don't cheap out):

• While not strictly OEM-only, many technicians prefer using genuine Honda sensors for critical transmission functions to ensure correct signaling and longevity. If avoiding the dealership, a high-quality OE-supplier brand is the next best choice.

Aftermarket brands forum-validated for this vehicle:

• NTK (a division of NGK, a major OE supplier for many Japanese brands)
• Beck/Arnley (often repackages OEM parts)
• Standard Motor Products (SMP) (generally considered a reliable aftermarket brand)

Brands owners have reported issues with on this vehicle:

• Unbranded, cheapest-available options from online marketplaces should be avoided, as their quality control and signal accuracy can be inconsistent, potentially leading to continued shifting problems or a rapid failure.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0716 — Refers to the same Input/Turbine Speed Sensor 'A' but indicates a 'Range/Performance' or intermittent signal problem, rather than the complete 'No Signal' indicated by P0717. This code can appear as the sensor begins to fail before it fails completely.
• P0722 — Indicates 'No Signal' from the Output/Vehicle Speed Sensor. This sensor is often physically located near the input speed sensor and can be confused during diagnosis, as noted by owners. A failure of either sensor can cause similar limp mode and shifting symptoms.
• P0700 — This is a general Transmission Control System (TCS) malfunction code. It is an informational code stored in the ECM to turn on the Check Engine Light when a more specific transmission-related code, like P0717, is stored in the Transmission Control Module (TCM).
• P0796 — This code for 'Pressure Control Solenoid 'C' Performance/Stuck Off' is noted to appear on platform mates like the Honda Fit with similar CVT issues. While a different component, erratic data from a failing speed sensor (P0717) can sometimes trigger hydraulic pressure codes.

Frequently Asked Questions