P0711: Transmission Fluid Temperature Sensor Range/Performance
What Does Code P0711 Mean?
The transmission Fluid Temperature (TFT) sensor is a varuable resistor, or also called thermistor which changes resistance value depending on the temperature of the transmission fluid. As the fluid temperature increases the resistance of the TFT decreases, and conversely as the temp decreases, the sensor resistance increases. The Powertrain control module (PCM or ECM) provides a 5-volt reference signal to the sensor and then measures the voltage drop across the circuit. When the transmission fluid is cool the sensor resistance is high and the computer detects high signal voltage. As the fluid temperature increases to normal operating temperature, the sensor resistance lowers and the signal voltage will decrease.
How The Code Is Set
Transmission Control Module (TCM) or the powertrain module detects very low or high voltage from the fluid sensor.
Code P0711 Symptoms
- Check Engine Light on
- Transmission shift problems
Common Causes of Code P0711
- A fualty TFT sensor
- Transmission Fluid Temperature wiring open or shorted
- Temperature sensor circuit poor electrical connection
- A faulty TCM or powertrain module
How to Diagnose P0711
As with any trouble code a scanner is an invaluable tool to help diagnosis. If you have one, look at the TFT sensor data when the transmission is cold then also when hot. Use a laser thermometer on the oil pan to compare the values. If they are not similar, then you need to go a little further. Use a digital volt / ohm meter and get a resistance chart that shows the relationship between temperature and resistance. These are availble online or in the vehicle service manual. Disconnect the sensor and test the resistance across the sensor. Then compare that to the temp chart to see if it is within range. The temperature and resistance won't be exact, but pretty close on a properly functioning TFT. If the sensor is reading good, then move along the wiring while moving the harness around to look for an intermitant problem. If all is good to this pint, then the transmission contol module or powertrain computer may be at fault.
What Will Fix Code P0711?
Proper diagnosis, replacing the sensor or fixing wiring or replacement of the computer. The sensor is a little difficult to replace. Depending on the veicle make and model, it is located either in the pan on the valve body or in the side cover. Clear all the computer codes after any repairs are made and take your vehicle for a test drive.
⇦ Code P0503; Code P0712 ⇨
