P0716 and P0717: input/turbine speed sensor circuit and no signal

An automatic transmission control module runs a continuous calculation: input shaft speed divided by output shaft speed gives the actual gear ratio. Compare that with the ratio it commanded, and you know whether the gearbox is doing what it was told.

Remove the input speed signal and the whole calculation collapses.

Code	Meaning
P0715	Input/turbine speed sensor circuit
P0716	Range/performance
P0717	No signal

Related: P0715 input turbine speed sensor and P0730 incorrect gear ratio.

What happens without it

The module cannot verify ratios, so it stops trying. The usual response:

• Limp mode, holding one gear — often third — to guarantee the car can still be driven.
• Harsh shifts, because shift pressure is calculated from speed data that is no longer available.
• No torque converter lockup.
• A speedometer that still works, because that comes from the output sensor or the ABS system.

That last detail helps: a car in limp mode with a working speedometer points at the input sensor rather than the output sensor.

Limp mode: what it is and how to exit.

P0716 versus P0717

P0717 — no signal. Nothing arriving. An open circuit, a dead sensor, or a sensor that has fallen out of position.

P0716 — range/performance. A signal exists but does not make sense: it disagrees with engine RPM and output speed in a way the physics does not allow.

That distinction matters because P0716 can be caused by actual slipping rather than by a sensor fault. If a clutch pack is slipping, input speed genuinely does not match output speed, and the sensor is reporting the truth.

Gears slipping on an automatic.

Sensor fault or real slip?

The question that decides whether this is a cheap repair or an expensive one.

Log engine RPM, input shaft speed and vehicle speed together.

Pattern	Meaning
Input speed absent entirely	Sensor or circuit — P0717
Input speed present, tracks engine RPM in lockup	Sensor healthy
Input speed rises while vehicle speed does not	Genuine slip
Input speed erratic at steady cruise	Sensor, wiring or a reluctor problem

Row three is the one that costs money. Revs climbing without matching acceleration is slip measured rather than guessed, and it points inside the gearbox.

Row four points back at the sensor.

Causes

The internal harness

Many transmissions route the sensor through an internal harness that exits via a sealed case connector. That seal hardens with heat and age, and fluid wicks up the wiring.

Fluid in the transmission connector is a specific finding and explains multiple simultaneous transmission codes without multiple failed components.

The sensor

Inductive or Hall, depending on the design. Both fail with heat and vibration. Some are external and accessible; others require dropping the valve body or the pan.

The reluctor

Debris from clutch wear sticks to the toothed wheel the sensor reads, adding phantom teeth. Metal in the pan is itself a finding — it means something inside is wearing.

Fluid condition and level

Low or degraded fluid causes genuine slip, which sets P0716 legitimately. Check level and condition before assuming electronics.

That check requires a working fluid temperature sensor on most modern gearboxes, because the level is specified at a temperature: P0710 to P0713 transmission fluid temperature sensor.

Read the transmission module, not just generic codes

Generic OBD-II gives you P0700 as a pointer and sometimes the specific code. The transmission module holds the detail — adaptation values, slip counters, and which clutch element the module thinks is failing.

P0700 transmission control system malfunction and scan tool limits.

Before agreeing to a rebuild

1. Check fluid level and condition properly.
2. Log input speed against engine RPM and vehicle speed.
3. Establish whether the sensor is external or internal, which sets the cost floor.
4. Check for fluid in the external connector.
5. Ask whether the pan has been dropped and what was in it.
6. Distinguish “no signal” from “signal showing slip” — they are different repairs.

This check needs no workshop — an ELM327 adapter and the free tier of the app cover it. Log engine RPM against vehicle speed on a steady motorway cruise. Revs that climb while speed holds constant is slip, recorded rather than argued about.