# P0717: Input/Turbine Speed Sensor "A" Circuit No Signal

**Verdict:** Drive to a shop this week

Transmission - Generic OBD-II code, applies to all gasoline cars and light trucks sold in the US since 1996.

- **Typical cost:** $100-$900
- **Urgency:** This week
- **Most likely:** Dead input sensor or open wiring
- **DIY?:** Possible if external

## Quick answer

P0717 means the transmission computer is getting no signal at all from the input or turbine speed sensor, which measures how fast the shaft entering the transmission spins. Without it, the computer cannot judge shifts or slip, so it often goes into limp mode. An open wire, an unplugged connector, or a dead sensor is the usual cause.

## What does P0717 mean?

The input speed sensor, also called the turbine speed sensor, reads how fast the transmission's input shaft turns, which is the speed coming out of the torque converter. The transmission computer compares it with engine speed to measure converter slip, and with output shaft speed to confirm each gear and time shifts. Most are magnetic or Hall-effect sensors that read teeth on a rotating part.

P0717 is narrower than P0715. It sets when the computer sees no pulses from the sensor while engine speed and other signals show the input shaft must be turning, such as when driving in gear above a set speed. A flat-zero reading usually means an open circuit, a dead sensor, or a disconnected plug, rather than a sensor reading slightly wrong. "A" refers to the first or only input speed sensor, since some transmissions have two.

## What are the symptoms of P0717?

- Transmission stuck in one gear (limp mode)
- Harsh or delayed shifts
- Higher RPM at highway speed because the converter will not lock
- Check engine light, sometimes a flashing gear indicator
- Speedometer still works normally on most vehicles

## What causes P0717?

Ranked from most to least likely. Check them in this order: the cheap, common causes first.

1. **Failed input speed sensor** (most common). The sensor sits in a hot, vibrating spot, and its internal coil or electronics can fail open, producing no signal at all. Failures may appear only when hot at first, then become constant. A resistance check on magnetic sensors, or a supply voltage and signal check on Hall-effect sensors, shows whether it is dead.
2. **Open wire or unplugged connector** (common). No signal often means the circuit is broken somewhere between sensor and computer. Connectors can be left unplugged or not fully latched after other work, and wires chafe through on brackets or melt near the exhaust. Rodents chewing harnesses is another cause on vehicles that sit parked. A continuity check end to end usually finds the break.
3. **Corroded or fluid-soaked connector** (common). Transmission fluid can wick past a failing sensor O-ring or harness seal into the connector, and road salt corrodes exposed terminals. Corrosion raises resistance until the weak signal never reaches the computer. Pins that look green or feel loose, or a code that sets after rain or car washes, point to the connector.
4. **Damaged tone ring or wrong sensor gap** (less common). The sensor reads teeth on a drum or gear inside the transmission. If debris coats the magnetic tip, the sensor was installed with the wrong spacer, or the toothed part is damaged, the sensor sees nothing even though it works. This is more likely after internal transmission work or a failure that shed metal.
5. **Computer input or supply failure** (rare). Rarely, the computer's input circuit or the supply voltage it sends to the sensor fails, often after a short in the sensor wiring. Some sensors share a reference voltage with other sensors, so several speed codes at once can point there. Checking supply voltage and signal at the computer connector confirms it.

## How do you diagnose P0717?

1. Read all transmission codes and check whether other speed sensor codes, such as P0720, are stored too.
2. Watch input speed on a scan tool while driving; a flat zero with the car moving in gear confirms no signal.
3. Inspect and reseat the sensor connector, and check for fluid, corrosion, or damaged wires.
4. Test sensor resistance or supply voltage, then check wiring continuity back to the computer.

## How do you fix P0717, and what does it cost?

| Fix | Typical cost | What it involves |
| --- | --- | --- |
| Repair wiring or connector | $100-$350 | Includes tracing and fixing an open or corroded circuit. |
| Replace external input speed sensor | $150-$450 | Usually one bolt and an O-ring, plus a fluid top-up. |
| Replace internal input sensor | $400-$900 | Means removing the pan or valve body, then refilling with fresh fluid. |

## Is it safe to drive with P0717?

> **Drive to a shop this week.** You can usually drive slowly to a shop, but limp mode often holds one gear, which makes merging and climbing hard and stresses the transmission. Avoid highways and towing until it is repaired.

## Will P0717 fail an emissions test?

P0717 turns on the check engine light, so the vehicle fails an OBD-II emissions test in most states. Because the transmission affects engine load and fuel economy, the fault counts as emissions-related. Clearing it resets the readiness monitors, and P0717 returns as soon as the car moves with no sensor signal, so fix it first.

## After the repair: clearing P0717

After the repair, clear transmission and engine codes, then drive through every gear. On a scan tool, input speed should rise and fall smoothly with engine speed and drop at each upshift. Some transmissions need a shift adapt relearn afterward. Normal shifts and no returning code over a few drives mean it worked.

## How to prevent P0717

- Make sure every transmission connector is fully latched after any nearby repair work.
- Change transmission fluid on schedule so metal debris does not build up on sensor tips.
- Fix leaks at sensor O-rings early, before fluid wicks into the wiring.
- Keep wiring clear of exhaust parts, and have heat-damaged harness sections repaired properly.
- Take steps against rodents if the vehicle sits parked for long periods.

## P0717 by make

| Make | What to know |
| --- | --- |
| Honda | On many older Honda and Acura automatics, a transmission speed sensor fault makes the D or D4 indicator blink along with the stored code. |

## Codes often seen with P0717

- [P0715](/codes/p0715): Input/Turbine Speed Sensor "A" Circuit
- [P0720](/codes/p0720): Output Shaft Speed Sensor "A" Circuit
- [P0700](/codes/p0700): Transmission Control System (MIL Request)
- [P0730](/codes/p0730): Incorrect Gear Ratio
- [P0741](/codes/p0741): Torque Converter Clutch Solenoid Circuit Performance/Stuck Off

## Frequently asked questions

### Can I drive with a P0717 code?

You can usually drive slowly to a shop, but expect limp mode, which often holds one gear and makes acceleration weak. Avoid highways, towing, and long trips. Driving far in limp mode or with harsh shifts can overheat or wear the transmission, turning a sensor repair into a bigger job.

### What is the difference between P0715 and P0717?

P0715 is the general input speed sensor circuit code, covering signals that are erratic, out of range, or missing. P0717 is more specific: the computer sees no signal at all while the input shaft must be turning. That usually points to an open circuit, an unplugged connector, or a dead sensor.

### Where is the input speed sensor?

On most vehicles it threads or bolts into the transmission case near the front, often on top or on the side. On some transmissions it sits inside, on the valve body or in the case, and requires removing the pan. Service information for your exact transmission shows its location.

### How much does it cost to fix P0717?

Most P0717 repairs cost $100 to $900 at an independent shop. A wiring or connector repair runs about $100 to $350 and an external sensor $150 to $450. An internal sensor that needs the pan or valve body removed usually costs $400 to $900 with fresh fluid.

### Can I replace the input speed sensor myself?

If the sensor is external and easy to reach, many home mechanics can replace it with basic tools. Clean the area first so dirt does not fall into the transmission, lube the new O-ring with fluid, and check the fluid level afterward. Internal sensors are usually a shop job.

### Can a bad input speed sensor cause limp mode?

Yes, losing the input speed signal is a common reason for limp mode. Without it, the transmission computer cannot check shifts or converter slip, so it protects the transmission by holding one gear. Normal shifting usually returns once the signal is restored and the codes are cleared.

### Will my speedometer stop working with P0717?

Usually not, because most vehicles take vehicle speed from the output shaft sensor or the wheel speed sensors, not the input sensor. A working speedometer with P0717 actually helps confirm the input side is the problem. If the speedometer also fails, check for an output sensor code such as P0720.

### Can low transmission fluid cause P0717?

Low fluid does not usually cause a no-signal code directly, since the sensor reads a rotating part, not the fluid. It can cause slipping codes alongside it, though. Check the fluid anyway, because a leaking sensor O-ring can let fluid escape and soak the sensor connector at the same time.

### Could P0717 mean something worse inside the transmission?

Occasionally. If the sensor and wiring test good, the toothed part it reads may be damaged, or debris may coat the sensor tip, which points to internal wear. Metal stuck to the sensor magnet is a warning sign. In most cases, though, P0717 turns out to be an electrical repair.

### Will P0717 clear itself?

It may disappear if a loose connector makes contact again, but it usually returns when the fault does. The transmission computer may stay in limp mode until the code is cleared or the engine restarts, depending on the vehicle. Fix the cause, then clear codes in both computers.

## Sources

- [SAE J2012: Diagnostic Trouble Code Definitions](https://www.sae.org/standards/content/j2012_201812/)
- [EPA: On-Board Diagnostics (OBD)](https://www.epa.gov/state-and-local-transportation/vehicle-emissions-board-diagnostics-obd)

## Other transmission codes

- [P0700 Transmission Control System (MIL Request)](https://diagxcar.com/codes/p0700)
- [P0705 Transmission Range Sensor "A" Circuit (PRNDL Input)](https://diagxcar.com/codes/p0705)
- [P0715 Input/Turbine Speed Sensor "A" Circuit](https://diagxcar.com/codes/p0715)
- [P0720 Output Shaft Speed Sensor "A" Circuit](https://diagxcar.com/codes/p0720)
- [P0730 Incorrect Gear Ratio](https://diagxcar.com/codes/p0730)
- [P0731 Gear 1 Incorrect Ratio](https://diagxcar.com/codes/p0731)
- [P0732 Gear 2 Incorrect Ratio](https://diagxcar.com/codes/p0732)
- [P0740 Torque Converter Clutch Solenoid Circuit/Open](https://diagxcar.com/codes/p0740)
- [P0741 Torque Converter Clutch Solenoid Circuit Performance/Stuck Off](https://diagxcar.com/codes/p0741)
- [P0750 Shift Solenoid "A"](https://diagxcar.com/codes/p0750)

## Symptoms

- [Why does my car jerk when I accelerate?](https://diagxcar.com/symptoms/car-jerks-when-accelerating)

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Source page: https://diagxcar.com/codes/p0717
Updated: 2026-11-03
General information, not a substitute for a qualified mechanic.