P0718 Input/Turbine Speed Sensor A Circuit Intermittent

P0718 points to an intermittent input or turbine speed sensor A circuit fault. The sensor signal disappears or glitches under certain conditions.

Code details

Generic OBD-II · P0

System: Transmission
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace the sensor solely because the code is intermittent; prove whether the dropout is sensor, wiring, or module side.

Symptoms of P0718

Harsh, delayed, or slipping shifts, or being stuck in one gear.
Check-engine light, sometimes with limp-home mode.
Flaring RPM or a shudder under load.

Common causes of P0718

Low or degraded transmission fluid.
A failing speed sensor, shift solenoid, or pressure-control circuit.
Wiring, connector, or internal hydraulic/mechanical faults.

Useful checks before replacing parts

Graph turbine speed while road testing over bumps, during hot operation, and while gently moving the related harness.
Inspect connector locking, terminal fit, sensor wiring, case connector condition, and possible heat-related internal harness faults.
Look for matching shift flares, ratio codes, or limp-mode events at the same moment the speed signal drops out.

Related OBD-II codes

These nearby transmission entries can help compare wording and pin down the fault area.