P0710 Code: Transmission Fluid Temperature Sensor A Circuit

What the P0710 code means

The sensor measures the temperature of the transmission fluid. The computer uses it to adjust pressure, shift smoothness and torque converter lockup, and to protect the transmission from overheating.

The sensor changes its resistance with temperature, and the computer measures the resulting voltage. A circuit fault can be caused by the sensor, the wiring or the power supply. That is what sets the P0710 code.

Without this signal the computer uses a fixed value, so shifts can be harsh when cold or the torque converter may not lock up. On many transmissions the sensor is part of the internal harness, so it is replaced by removing the pan. See the sensor guide to learn how to test it.

Always start with the simplest checks: fuse, relay and connector. Then check power, ground and signal with the component connected (using back probing pins) and, last, the continuity of each wire back to the computer. Only replace the component if all of that checks out.

P0710 code symptoms

• Check engine light on.
• Harsh shifts or a torque converter that does not lock up.
• Harsh shifts when the transmission is cold.
• Engine rpm a little high on the highway.

Likely causes of the P0710 code

1. Damaged or corroded connector. The most frequent cause.
2. Wiring that is cut or shorted between the sensor and the computer.
3. Failed sensor, open or internally shorted.
4. Missing supply reference. Check whether other sensors are also failing.
5. Computer. Uncommon, so rule out everything above first.

How to diagnose the P0710 code step by step

1. Read the sensor value on the scan tool and compare it with what is expected.
2. Inspect the connector for corrosion, water and loose pins.
3. Check power and ground with the key on: a correct reference and less than 0.1 volt drop on the ground.
4. Measure the signal with the connector plugged in and see whether it changes with the condition.
5. Do a wiggle test of the wiring with the scan tool in graph mode.
6. Check the continuity of each wire back to the computer (under 1 ohm).
7. With the transmission cold, compare its temperature with the coolant temperature. They should be close to each other.

How to fix the P0710 code

• Repair the connector or the wiring.
• Replace the sensor if the tests confirm it is bad.
• Correct the real condition if there is one.
• Clear the P0710 code and verify with a road test.

Technical reference data

• NTC thermistor: high resistance when cold and low resistance when hot.
• Normal fluid temperature: 70 to 95 °C (158 to 203 °F).
• Reference values only: check the manufacturer data for your vehicle.

Brand-specific notes

The source notes how the sensor is mounted on two brands.

P0710 on GM

On GM the sensor is built into the internal harness of the transmission or into the control module.

P0710 on Ford

On Ford the sensor is built into the internal harness of the transmission or into the control module.

Frequently asked questions about P0710