The input or turbine shaft speed sensor – a Hall sensor with square-wave output or an inductive sensor with sine output – reports the speed behind the torque converter. With output and engine speed it gives the actual gear ratio, converter slip and shift timing. P0718 means the signal is present but jumps or drops out briefly. Ford's petrol modules from 2012 to 2023 count 200 turbine speed spikes above 400 rpm with at most 1.5 s between them in a forward gear. GM's Honda-built five-speed of 2006 flags jumps of more than 3 mph per 10 ms three times in 500 ms, after two trips; GM's own transmissions file such jumps under P0716 instead. Loose contacts and electrical interference are the usual causes; shifts become erratic and limp mode may follow at times.
Medium severity. Can I keep driving?Drive gently to a repair shop. If it slips, you hear clunks, or it loses its gears, do not keep driving.
Symptoms
- Occasional harsh or unexpected shifts
- Warning lamp
- Converter clutch applies and releases unevenly
- Limp mode at times
Most likely causes
- Loose contact, corroded connector or chafing
- Electrical interference (shielding, ground, added consumers)
- Metal debris on the sensor or loose mounting
- Sensor faulty internally (temperature-dependent)
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P0718 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 7: Transmission
- 18: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0718?
Drive gently to a repair shop. If it slips, you hear clunks, or it loses its gears, do not keep driving.
What causes code P0718?
The most common causes are: loose contact, corroded connector or chafing; electrical interference (shielding, ground, added consumers); metal debris on the sensor or loose mounting.
Related codes
- P0715Input/Turbine Shaft Speed Sensor A Circuit
- P0716Input/Turbine Shaft Speed Sensor A Circuit Range/Performance
- P0717Input/Turbine Shaft Speed Sensor A Circuit No Signal
- P0723Output Shaft Speed Sensor Circuit Intermittent
Sources
- newtonnet.co.uk: fordobd2012
- fordservicecontent.com: OBD Operations Summary Gasoline 2020 2023
- gsi.ext.gm.com: 2006trans8
- roushcleantech.com: Roush CleanTech Diagnostics Manual DA 8.5.18
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.