Usually drivable; fix soon to protect the transmission. P0710 means the transmission computer has seen the transmission fluid temperature (TFT) sensor signal drop outside its valid range, so it can no longer trust the fluid temperature it reads. The fault is almost always in the sensor itself or its wiring rather than in the transmission's internals.
What P0710 means
P0710 is set when the transmission control module (TCM) sees the transmission fluid temperature (TFT) sensor signal fall outside its valid window. The TFT sensor is a negative-temperature-coefficient (NTC) thermistor mounted in the valve body or fluid pan; the module feeds it a reference voltage and reads the voltage that returns across the sensor. Because it is an NTC device its resistance drops as the fluid warms up. On a typical unit the winding spans from roughly 156 kilohms when the fluid is frozen near -40 degrees C down to under 100 ohms as it approaches 150 degrees C. The module converts that resistance into a temperature and uses it to schedule shift timing, line pressure, and torque-converter-clutch lockup, and to trigger overheat protection. P0710 is the base circuit code: it logs when the measured resistance stays pinned below the low limit (around 79 ohms) or above the high limit (around 156 kilohms) for a short qualifying period, usually about half a second. That out-of-range reading tells the module the circuit is shorted, open, or has failed, so it substitutes a default temperature and flags the fault.
Symptoms
- Check-engine light on with a stored P0710; some vehicles also light a transmission or overdrive warning lamp
- Harsh, delayed, or erratic shifts because the module falls back to a fixed default temperature instead of a real reading
- Torque converter clutch will not lock up, so engine RPM stays higher than normal at a steady cruising speed
- The transmission drops into limp or fail-safe mode on some vehicles, holding a single gear until the fault is cleared
- Worse fuel economy and a hotter-running transmission because temperature-based protection strategies no longer work correctly
Common causes
- A failed TFT/ATF thermistor that has gone open or shorted internally — the single most common cause
- Damaged wiring or a chafed harness between the transmission and the control module
- Corroded, spread, or backed-out terminals at the internal transmission connector
- Low, burnt, or contaminated fluid fouling the internal connector and sensor
- A faulty control module or a problem on its sensor reference circuit — the least common cause
Severity & driving advice
Severity: Moderate — The car still drives, but the module loses real fluid-temp data and may block converter lockup or hold safe shift settings, adding heat.
Can I drive? Usually drivable; fix soon to protect the transmission
Diagnostic approach
- Scan codes and read the live temperature PID — Record every stored and pending transmission code and check the freeze-frame data. Then watch the fluid-temperature parameter on a scan tool with the engine cold. A reading that is stuck at the extreme low value (around -40 degrees C) points to an open circuit, while a reading pinned at the maximum (roughly 150 degrees C or higher) points to a short. A cold reading that tracks ambient temperature means the sensor is likely healthy.
- Check transmission fluid level and condition — Confirm the fluid is at the correct level and is clean, not dark, thin, or burnt-smelling. Low or badly degraded fluid can corrode the internal connector and disturb the sensor circuit, producing an erratic or out-of-range signal. Correct the level or service the fluid to the maker's spec before condemning electrical parts.
- Measure sensor resistance against the temperature curve — With the key off, measure the TFT sensor's resistance and compare it to the fluid temperature. As an NTC thermistor its resistance should fall as the fluid warms, staying inside a working band of roughly 79 ohms to 156 kilohms across the full temperature range. An infinite (open) reading or a near-zero (shorted) reading confirms a failed sensor. Cold fluid should read high resistance; hot fluid should read low.
- Inspect the harness, connector, and isolation to ground — Follow the two-wire circuit from the module to the transmission connector and inspect for chafing, corrosion, spread terminals, or fluid intrusion. Both signal and sensor-ground wires should be isolated from chassis ground, typically reading about 10 kilohms or higher to any other terminal. Wiggle-test the harness with the meter connected to expose an intermittent open or short.
- Verify the signal at the module and rule out the TCM — If the sensor and wiring check out, confirm the reference voltage is present at the sensor connector and that the resistance seen back at the module terminals matches the sensor's value. Only after the sensor, wiring, and connectors pass should you suspect the control module, since a module fault for this code is uncommon.
Make & model notes
Chrysler: On Chrysler, Dodge, Jeep, and Ram automatics the TFT thermistor sits inside the valve body, often as part of the internal solenoid/sensor assembly, and P0710 is reported as the base transmission fluid temperature sensor circuit fault. When the module cannot trust the reading it substitutes a default temperature and may hold the transmission in a fail-safe gear. Check the internal transmission connector for fluid intrusion or spread terminals before replacing the sensor.
Toyota: Toyota rarely uses the bare P0710. Its ECM splits the same ATF (TFT) sensor fault into P0712 for a short (resistance below about 79 ohms, read as roughly 150 degrees C) and P0713 for an open (above about 156 kilohms, read as -40 degrees C), each confirmed in about half a second. Confirm the resistance between the sensor signal (THO1) and sensor-ground terminals lands inside the 79-ohm to 156-kilohm band.
General Motors: On GM units the TFT sensor shares a two-wire circuit routed through the internal transmission connector, and GM logs P0710 as the general circuit malfunction. A frequent trigger is a corroded or spread terminal at that internal connector rather than a dead sensor, so inspect and reseat it before parts replacement.
FAQ
Is P0710 the same as P0711, P0712, and P0713?
They all involve the transmission fluid temperature sensor but describe different faults. P0710 is the general circuit code. P0711 is a performance or range code, meaning the sensor reads but the value is implausible. P0712 is a low-input (short) fault where resistance falls below the low limit, and P0713 is a high-input (open) fault where resistance rises above the high limit. Some makes, such as Toyota, use the P0712 and P0713 pair instead of the bare P0710.
Can I keep driving with P0710?
For short trips it is usually drivable, but do not ignore it. Without a trusted temperature the module defaults to safe shift settings, may refuse to lock the torque converter, and cannot run its overheat protection. That means more heat and slightly worse economy, and some vehicles drop into limp mode. Have it diagnosed before the added heat starts to shorten the life of the fluid and internal parts.
How do I test the transmission fluid temperature sensor?
With the ignition off, measure the sensor's resistance and compare it to the fluid temperature. As an NTC thermistor its resistance should be high when cold and fall as the fluid warms, staying within a working band of roughly 79 ohms to 156 kilohms. An open (infinite) or shorted (near-zero) reading confirms a failed sensor. Also confirm the two wires are isolated from ground, typically 10 kilohms or higher to any other terminal.
Will P0710 put my transmission in limp mode?
It can on some vehicles. When the module decides it cannot trust the temperature signal, it may command a fail-safe strategy that holds a single gear and locks out the torque converter clutch to protect the transmission from an unknown temperature condition. Clearing the code after the circuit is repaired usually restores normal shifting, but the fault will return if the underlying sensor or wiring problem is not fixed.