P0715 Transmission Input Speed Sensor Circuit
Get it checked soon
The transmission cannot see its input speed. Expect harsh shifts or limp mode. It is often the sensor or its wiring, but check the fluid too.
- Safe to drive?
- To a shop, not for weeks
- Typical cost at a shop
- $294-$1,006 RepairPal national averages, parts and labor
- Emissions test
- Yes, while the check engine light is on, most OBD emissions tests fail the car.
- Carmaker bulletins
- 1 note with links
What it means
The input (turbine) speed sensor tells the transmission computer how fast the transmission input is turning. The computer compares it with engine speed and output speed to know which gear it is in and when to shift. P0715 means the signal is missing or does not make sense, so the computer has to guess.
The technical version
The TCM checks that input speed is present and plausible for the gear and engine speed. A missing or erratic signal sets P0715 and often puts the transmission in a fail-safe gear. Some cars need a software update for this code (see make notes).
Official name: Input/Turbine Speed Sensor Circuit Malfunction.
Symptoms
- Harsh or badly timed shifts.
- Engine revs flare between gears.
- A dead speedometer on some cars.
- Limp mode stuck in one gear.
Causes, most likely first
| Cause | How likely | How to tell |
|---|---|---|
| A failed input or turbine speed sensor | most common | Input speed reads zero while the engine turns. |
| Wiring or connector damage | common | The signal drops in and out. |
| Metal debris on the magnetic sensor tip | less common | Debris on the sensor when removed. |
| Very low or worn fluid | less common | Fluid check. |
| Software, on some models | less common | A bulletin for your car (see make notes). |
| Internal damage to the part the sensor reads | rare | Sensor and wiring test good. |
How likely is our ranking from repair data and common practice, not a published rate.
What the live data shows
Where the car reports transmission data, input speed that disagrees with engine speed tells the story: the engine at 2,500 rpm while input speed reads zero or jumps is a sensor or wiring sign. If engine rpm flares during a shift while road speed rises smoothly, that is real slip, a more serious finding.
What to check first, in order
-
Read the transmission module codes and freeze frame.
Confirms the code and any companions.
What the data shows: Input speed versus engine speed.
Cost: no cost if you have a scanner
-
Check the connector and wiring at the transmission.
Cheap and common.
What the data shows: Watch input speed while you move the harness.
Cost: free to look
-
Check fluid level and condition.
Low fluid and debris cause faults.
What the data shows: Fluid temperature where supported.
Cost: $294-$356 at a shop (Transmission fluid change, RepairPal)
-
Check for a software bulletin.
Some cars need a reprogram.
What the data shows: No reading needed.
Cost: free to check
-
Replace the input speed sensor.
External and cheaper on many transmissions.
What the data shows: Input speed tracks engine speed.
Cost: $395-$506 at a shop (Vehicle speed sensor replacement (closest RepairPal page to an input speed sensor), RepairPal)
Is it safe to drive?
Get it checked soon
To a shop, not for weeks. The transmission is shifting on guesses.
Expect symptoms, not just a light: harsh shifts, rev flare, maybe limp mode. It is drivable to a shop, not for weeks, because erratic shifting is hard on a transmission. If it drops into limp mode on the highway, get it in now.
Stop driving and get help if
- It slips or flares badly.
- It is stuck in one gear at highway speed.
What it costs
| Repair | Typical cost |
|---|---|
| Transmission fluid changeRepairPal, updated September 3, 2026 | $294-$356 |
| Vehicle speed sensor replacement (closest RepairPal page to an input speed sensor)RepairPal, updated September 3, 2026 | $395-$506 |
| Transmission control module replacementRepairPal, updated September 3, 2026 | $929-$1,006 |
National averages for the full job at a shop, parts and labor, from RepairPal (updated September 3, 2026). Your price depends on the car and the area. Many of the first checks on this page cost nothing with a scanner.
Can I clear it? Will it come back?
After the repair, clear the code and drive through all gears. Input speed should track engine speed.
Will it fail an emissions test?
Yes, while the check engine light is on, most OBD emissions tests fail the car.
Carmaker notes
Service bulletins and warranty extensions that name this code. Ask a dealer to check your VIN.
-
Nissan 2022 Pathfinder built before March 21, 2022
Nissan bulletin NTB22-030 (April 2022): 'Service at power reduced' warning with P0715 stored. The fix is a transmission computer reprogram.
Nissan NTB22-030 via NHTSA static.nhtsa.gov
Related codes
Also related, no guide yet: P0720, P0717.
How Obie handles P0715
Obie compares input speed with engine speed where the car reports both, and tells you whether it looks like a sensor or real slip. Obie is part of ScanMyCar Pro. Codes and live sensors are free.
Questions people ask
Can I drive with P0715?
To a shop. Erratic shifting is hard on the transmission.
Is P0715 the transmission itself?
Usually not. It is most often the sensor or its wiring.
Where is the input speed sensor?
On the transmission case on many cars; inside it on some. Your repair manual shows it.
Sources
- RepairPal: P0715 code page repairpal.com
- RepairPal: Transmission fluid change (updated September 3, 2026) repairpal.com
- RepairPal: Vehicle speed sensor replacement (closest RepairPal page to an input speed sensor) (updated September 3, 2026) repairpal.com
- RepairPal: Transmission control module replacement (updated September 3, 2026) repairpal.com
- Nissan NTB22-030 via NHTSA static.nhtsa.gov
- Texas DPS emissions testing FAQ dps.texas.gov
- Arizona myazcar.com: OBD and the check engine light myazcar.com
A guide, not a diagnosis. This page describes what P0715 generally means across OBD2 cars. What is actually wrong with your car depends on its live data and its history, and any repair decision deserves a proper diagnosis, whether that is you with a scanner or a professional with a lift.
