Can I drive in limp mode to the dealer?

Short distances, yes. Limp mode typically locks you into second or third gear. Avoid highway driving in limp mode.

Is the sensor accessible without dropping the transmission?

On most vehicles, yes. Input speed sensors are typically on the outside of the transmission case. Some require removal of a bellhousing cover.

Should I change the transmission fluid at the same time?

Yes, especially if it has not been changed recently. Metal contamination in the fluid damages sensors and valves.

Codes › P0715

P0715: The transmission cannot measure its input shaft speed

Input/Turbine Speed Sensor A Circuit Malfunction

High severityCan you keep driving?

Drive only to a shop. Without input speed data, the transmission may shift harshly, refuse to shift, or go into limp mode. Continued driving risks transmission damage.

What it means

The input speed sensor measures how fast the transmission's input shaft is spinning. The TCM uses this data to calculate slip across the torque converter and to control shift timing and pressure. Without it, the transmission is operating blind on those calculations. P0715 means the signal from this sensor is missing or out of range. The sensor itself is the most common failure, but fluid contamination from a worn transmission can also destroy sensors quickly, so check fluid condition alongside the sensor.

Common causes

Failed input speed sensorThe magnetic sensor wears or the tip breaks off from contact with the tone ring.
Damaged or corroded wiring to the sensorLocated inside the transmission bellhousing area; wiring exposure varies by design.
Contaminated or metal-particle-laden transmission fluidMetal debris from internal wear can damage the sensor or its tone ring.
Damaged reluctor ring (tone wheel)The toothed ring the sensor reads can shed teeth or corrode.

What it costs

Input speed sensor replacement$150 to $400
Transmission fluid and filter service$100 to $250
Wiring repair$80 to $300

Symptoms

Harsh or erratic shifting
Transmission limp mode
Torque converter clutch will not lock up
Speedometer inaccurate in some vehicles
Check engine and transmission warning lights

What to do next

Check the transmission fluid level and condition first. If it is dark, burned, or has metal particles in it, the transmission has internal wear and replacing only the sensor will not address the underlying damage. If fluid is in good condition, the sensor itself or its wiring is the likely fix.

Lewis shows the live input speed sensor signal and compares it to vehicle speed so you can see whether the signal is completely absent or just erratic under certain conditions. Download Lewis.

Related codes

FAQ

Can I drive in limp mode to the dealer?: Short distances, yes. Limp mode typically locks you into second or third gear. Avoid highway driving in limp mode.
Is the sensor accessible without dropping the transmission?: On most vehicles, yes. Input speed sensors are typically on the outside of the transmission case. Some require removal of a bellhousing cover.
Should I change the transmission fluid at the same time?: Yes, especially if it has not been changed recently. Metal contamination in the fluid damages sensors and valves.