Transmission · Powertrain · generic (SAE-defined)
P0712: Transmission Fluid Temperature Sensor "A" Circuit Low
P0712 means the transmission fluid temperature sensor signal voltage is lower than normal, which the computer reads as an implausibly high fluid temperature.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0712 sets
The transmission fluid temperature sensor is typically a thermistor whose resistance falls as temperature rises, pulling the signal voltage lower. When the transmission control module (TCM) sees the voltage below its valid range for a set time, it assumes a short to ground or failed sensor and sets P0712. Thresholds are manufacturer-specific.
Common causes of P0712
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Sensor signal wire shorted to ground
- Internally shorted fluid temperature sensor
- Damaged internal transmission harness
- Fluid or moisture inside the transmission connector
- TCM fault
P0712 symptoms
- Check engine light on
- Fluid temperature reading very high in live data on a cold vehicle
- Firm shifts or early converter lockup
- Transmission overheat warning on some vehicles
- Possible reduced performance mode
How P0712 is diagnosed
- Record freeze frame data and compare fluid temperature with ambient and coolant temperatures
- Inspect the transmission connector and harness for chafing or fluid intrusion
- Disconnect the sensor and see whether the reading drops to an extreme cold value, which suggests a shorted sensor
- Check the signal wire for a short to ground
- Measure sensor resistance and compare with the manufacturer's chart
Typical fixes for P0712
- Replace the fluid temperature sensor or internal harness
- Repair wiring shorted to ground
- Clean and seal the transmission connector
- Replace or reprogram the TCM if it is faulty
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Related codes & warning lights
P0712 FAQ
What does code P0712 mean?
P0712 means the transmission fluid temperature sensor signal voltage is lower than normal, which the computer reads as an implausibly high fluid temperature. The standard definition is "Transmission Fluid Temperature Sensor "A" Circuit Low."
Can I drive with a P0712 code?
Generally yes for a short time, but shift quality and converter lockup may change. Schedule diagnosis within a few days so a real overheating condition is not masked.
Why does a low voltage mean high temperature?
The sensor's resistance drops as fluid gets hotter, so voltage falls. A short to ground produces the same low reading, which the computer interprets as extreme heat.
Can a pinched wire under the vehicle cause P0712?
Yes. A harness pinched against the transmission or frame can short the signal to ground and set this code.
Keep researching
More transmission codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.