OBD-II trouble code
P0717: Input / Turbine Speed Sensor No Signal
The input (turbine) speed sensor circuit is producing no signal at all while the transmission is clearly turning. Where P0715 covers an erratic or out-of-range reading, P0717 is the total-dropout case — the TCM sees nothing where it should see shaft speed.
Quick facts
- System
- Powertrain
- Category
- Transmission / Speed Sensor
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $200 – $800 (external input speed sensor replacement)
- DIY difficulty
- Intermediate DIY
Browse every code in P0700–P0799, or start from the full code library.
What does P0717 mean?
P0717 is the 'no signal' member of the input speed sensor family, and the contrast with P0715 is the key to diagnosing it. P0715 sets when the input/turbine speed signal is present but erratic, implausible, or out of range. P0717 sets when there is no signal at all — the TCM expects to see the input shaft turning (because the engine is running, a gear is engaged, and the vehicle is moving) but the input speed reads a flat zero. That clean dropout is consistent with an electrical open, and a marginal sensor is still on the list: a broken wire, a disconnected or corroded connector, a completely dead sensor, or in some cases a reluctor that's so damaged the sensor produces nothing.
The distinction matters because it changes where you look first. An erratic P0715-style signal makes you suspect a partially shorted wire, a chipped tone ring, or a sensor on its way out. A dead-flat P0717 signal makes you suspect a full open in the circuit — and one check is the connector and wiring before the sensor is condemned. Back-probe or unplug-and-inspect the sensor connector, and watch whether the signal reappears when you reseat it. A connector that has corroded or backed out is one cause of a complete signal loss, and it does not require a new sensor.
Functionally, P0717 hits the transmission the same way P0715 does. The TCM relies on input speed to calculate gear ratio, verify the commanded gear, and manage converter slip and lockup. With the input signal gone entirely, it may drop into limp mode — a single fixed gear with adaptive shifting disabled — to protect the hardware. The list is a failed sensor, an open or corroded wiring or connector path, and internal damage. Because the signal is fully absent rather than just noisy, wiring and connector inspection is the check that does not require opening the case.
Common causes
- Open circuit in the input speed sensor wiring (broken or disconnected wire)
- Disconnected, backed-out, or heavily corroded sensor connector
- Completely failed input/turbine speed sensor
- Damaged reluctor / tone ring producing no readable pattern
- Chafed wire shorted to ground killing the signal
- Metal debris or fluid intrusion that has destroyed the sensor
- TCM internal fault on that sensor input (rare)
- Sensor left unplugged or mis-seated after a recent transmission repair
- Low or contaminated fluid contributing to sensor failure over time
Symptoms
- Check engine light on with P0717 stored
- Transmission locked in one gear (limp mode)
- Input speed reads zero in live data while the vehicle is clearly moving
- Harsh engagement and no adaptive shifting
- Torque converter clutch not locking up
- Possible speedometer or cruise-control effects on some platforms
- The symptom can appear suddenly and completely rather than intermittently
Diagnostic steps
- 1.Read live data with the vehicle moving and confirm the signature: input speed flat at zero while output speed and road speed are clearly non-zero indicates a complete signal loss. Have a passenger read the scan tool or use its record-and-play-back function — the vehicle is already in limp mode and holding a fixed gear, which is not the moment to be reading a screen from the driver's seat.
- 2.Inspect and reseat the connector before buying a sensor. A no-signal code is consistent with an open circuit, a disconnected connector, or a dead sensor. The connector is first because it is outside the case, not because a counted share of cases is published.
- 3.Unplug-and-inspect the sensor connector, looking for corrosion, backed-out pins, or fluid intrusion; reconnect and watch whether the signal returns.
- 4.Check continuity of the signal and ground wires from the sensor to the TCM to locate an open.
- 5.Test the sensor in the way its type allows. On a two-wire magnetic pickup, an open or badly out-of-spec resistance reading condemns that two-wire sensor. A three-wire Hall-effect or active sensor has no coil to open, so it cannot be condemned that way — check that it has supply and ground at the connector first, because an active sensor starved of either produces exactly this dead-flat nothing while being perfectly good itself.
- 6.If the circuit and sensor test good, inspect the reluctor/tone ring for damage, which requires dropping the pan and is a larger job.
Repair cost
$200 – $800 (external input speed sensor replacement)
This pair is an external input speed sensor. When the sensor is the external case-mounted type RepairPal describes for a vehicle speed sensor — one or two fasteners — that estimator's average, updated 3 September 2026, is $395–$506, with examples from about $204 on a Civic to about $817 on an Altima. An internal sensor is not that job. RepairPal's transmission fluid change average, updated 3 September 2026, is $294–$356, with vehicle examples from about $162 to about $463. AutoZone's published band for a transmission rebuild is $1,800–$3,500, and for a full replacement $4,000–$8,000. Opening the transmission for a reluctor or for debris is not in this pair.
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DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.