P0712: Transmission Fluid Temperature Sensor A Circuit Low
What to do
The transmission may refuse to use its higher gears or lock up the converter, which feels like a serious fault and usually is not. If a transmission overheat warning appears alongside this code while the vehicle has been driven gently and briefly, treat the reading with suspicion rather than the gearbox.
What this code means
The fluid temperature signal is below its valid voltage range, typically a short to ground. These sensors are thermistors whose resistance falls as temperature rises, so a short to ground is electrically identical to fluid that is impossibly hot — and the module responds accordingly.
That response is the reason this code is worth attending to promptly. Believing the fluid is overheating, the module inhibits torque converter lock-up and may restrict the gears it will use, so the vehicle behaves as though it is in trouble when nothing mechanical is wrong. It is a fault that manufactures its own alarming symptoms.
Likely causes
Start here
- Wiring shorted to ground · moderate
- Faulty transmission fluid temperature sensor · moderate
Less common
- Fluid tracking into the transmission connector · moderate
- Corroded transmission connector · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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