What P0712 means
The transmission fluid temperature sensor is an NTC thermistor whose resistance falls as the fluid warms; the module feeds it with 5 V through a resistor.
How the engine computer detects it
A low signal therefore means very hot or a short to ground, a high signal very cold or an open circuit. P0712 means the signal is too low – the sensor reads extremely hot, or the signal wire is shorted to ground. GM's 2025 transmission modules flag below 13.5 Ω for 5 of 6 s after two trips; the 2018 LT4 engine module below 17.88 Ω (over 150 °C (302 °F)) without MIL; the 2007 Allison 1000 150 °C (302 °F) or more for 2.5 s; Saab's AF40 over 200 °C (392 °F); Ford below 0.05 V for 5–12 s without MIL. The module substitutes a value (coolant temperature, 80 °C (176 °F) or a hot mode) and may shift with hot-fluid strategy. Real overheating with a good sensor is P0218.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Transmission in hot mode (early converter clutch, changed shift points)
- Harsh shifts
- Extremely high fluid temperature shown
- Check engine or transmission lamp depending on manufacturer
Common causes
- Signal wire shorted to ground (internal harness, chafing) Most likely
- Sensor shorted internally Possible
- Transmission actually severely overheated Less likely
- Control module faulty Less likely
How to diagnose P0712
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: transmission fluid temperature sensor, transmission internal harness, transmission control module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 7
- Transmission
- 12
- Specific fault
Questions drivers ask
Can I drive with code P0712?
If the car shifts normally, drive gently to a shop. If it's stuck in one gear, slips, shifts harshly or won't move out of Park, don't drive it: have it towed.
Will P0712 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.