P0710: Transmission Fluid Temperature Sensor A Circuit
What to do
Shifts will probably feel firmer than usual and stay that way however long you drive, and economy may drop. Not urgent, but worth fixing rather than living with — the module is protecting the transmission with a blunt instrument because it no longer knows how hot the fluid is.
What this code means
The transmission fluid temperature signal is missing or out of range. This reading does more work than its modest name suggests: fluid viscosity changes substantially with temperature, so the module uses it to decide how much pressure a given shift needs, when torque converter lock-up may be allowed, and when to protect itself by restricting what it will do.
Without a trustworthy reading the module assumes the worst case. In practice that means firmer shifts that never soften as the vehicle warms, and lock-up either delayed or withheld entirely — the latter costing noticeable fuel economy at cruise, since without lock-up the converter is always slipping a little.
Likely causes
Start here
- Faulty transmission fluid temperature sensor · moderate
- Corroded transmission connector · moderate
Less common
- Open circuit in sensor wiring · moderate
- Fluid tracking into the transmission connector · moderate
Rare
- Faulty transmission control module · specialist
Symptoms
Components involved
Information, not instruction
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Community experience
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