The transaxle fluid temperature (TFT) sensor is a positive temperature coefficient thermistor, temperature sensitive resistor, that provides information to the transmission control module (TCM) regarding transaxle fluid temperature. The temperature sensor is located in the valve body. Calculated temperature is a factor used to determine the shift time and shift delay time.
The internal electrical resistance of the sensor varies in relation to the operating temperature of the transaxle fluid.
The TCM sends a 5-volt reference signal to the temperature sensor and measures the voltage rise in the electrical circuit. A higher fluid temperature creates a higher resistance in the temperature sensor, there by measuring a higher voltage signal.
The TCM measures this voltage as another input to help control line pressure, shift schedules, and torque converter clutch (TCC) apply. When the transaxle fluid temperature reaches 120°C (248°F), the TCM enters hot mode. Above this temperature, the TCM modifies transaxle shift schedules and TCC apply in an attempt to reduce fluid temperature by reducing transaxle heat generation.
This diagnostic procedure supports the following DTC:
DTC P0711 Transmission Fluid Temperature (TFT) Sensor Performance
• | The temperature has not changed more than 3.5°C (38.3°F). |
• | The engine speed is greater than 500 RPM. |
• | The system voltage is greater than 9 volts. |
• | No CAN error DTCs P1671, P1672, or P1673 are set. |
• | No vehicle speed error DTCs P0720, P0721, or P0722 are set. |
• | The vehicle speed is greater than 20 km/h (12 mph) for 500 seconds cumulative. |
• | The temperature at start up is between -40°C to +20°C (-40°F to +68°F). |
• | The engine coolant temperature has changed by more than 50°C (122°F) since start up. |
• | The hold lamp will blink. |
• | The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer. |
• | The TCM assumes the transaxle fluid temperature is 60°C (140°F). |
• | No influence on driveability |
• | The blinking hold lamp will turn OFF when the malfunction has not occurred after 3 ignition cycles. |
• | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
• | Using a scan tool can clear history DTCs. |
When DTC P0711 sets, the possible cause of the fault could be the TFT sensor.
Step | Action | Values | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Automatic Transmission? | -- | Go to Step 2 | |||||
2 |
Did either of the fail conditions occur? | -- | Go to Step 3 | Go to Diagnostic Aids | ||||
3 |
Is the resistance equal to the specified value? | 990 ohms | Go to Step 7 | Go to Step 4 | ||||
4 |
Was a condition found? | -- | Go to Step 5 | Go to Step 6 | ||||
5 | Replace the automatic transaxle wiring harness. Did you complete the replacement? | -- | System OK | -- | ||||
6 | Replace the TFT sensor. Is the action complete? | -- | System OK | -- | ||||
7 |
Is the resistance equal to the specified value? | 0 ohms | Go to Step 9 | Go to Step 8 | ||||
8 |
Did you complete the repair? | -- | System OK | -- | ||||
9 |
Is the voltage within the specified range? | 9-16 V | Go to Step 10 | Go to Step 11 | ||||
10 |
Did you complete the repair? | -- | System OK | -- | ||||
11 | Replace the TCM. Refer to Transmission Control Module Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||
12 |
Has the last test failed or is the current DTC displayed? | -- | Go to Step 1 | System OK |