For 1990-2009 cars

Table 1: | DTC P0710 - TFT SENSOR Performance - Low Temp

### DTC P0710 - TFT Sensor Performance - Low Temp

### Circuit Description

The engine coolant temperature (ECT) sensor, intake air temperature (IAT) sensor and transaxle fluid temperature (TFT) sensor are thermistors that vary resistance according to changes in engine coolant, air induction and transaxle fluid temperature. The powertrain control module (PCM) supplies a 5-volt reference through a pull-up resistor to each sensor, which are connected to ground. When each sensor is cold it has high resistance, high signal voltage at PCM. As the sensor temperature increases, its resistance decreases, lower signal voltage at PCM. The PCM uses the signal voltage to determine engine coolant, air induction and transaxle fluid temperature. DTC P0710 sets when the transaxle fluid temperature is below a calibrated temperature, above a calibrated voltage, based on the ECT and IAT temperatures. This DTC compares the temperatures of the ECT, IAT and TFT for rationality.

### DTC Parameters

DTC P0710 will set if TFT sensor temperature is below a calibrated temperature, above a calibrated voltage, based on ECT and IAT sensor temperatures when:

• | Condition exists for longer than 21 minutes and 20 seconds

• | Condition exists twice in one ignition cycle

• | No ECT, IAT, P0712 or P0713 DTCs have been set

DTC P0710 diagnostic runs continuously once the above conditions have been met.

DTC P0710 is a type A DTC.

### Diagnostic Aids

DTC P0710 indicates a skewed ECT, IAT or TFT sensor or increased sensor circuit resistance.

Check for skewed high ECT temperature, skewed high IAT temperature or skewed low TFT temperature by comparing each value to each other after vehicle has been turned Off for over a 6 hour period. Each sensor temperature should be within 2°C of each other.

For this DTC to set, the TFT temperature must be less than (ECT + IAT)/2-40 in °C. This must exist along with the other DTC parameters.

#### DTC P0710 - TFT SENSOR Performance - Low Temp

** COMBINATIONS | SENSOR TEMPERATURE FAULT
--- | ---
ECT | IAT | TFT
1 | Skewed High | Normal | Normal
2 | Normal | Skewed High | Normal
3 | Normal | Normal | Skewed Low
** These combinations can set DTC P0710

ECT, IAT and TFT SENSOR RESISTANCE VALUES vs TEMPERATURE
Temperature | SENSOR RESISTANCE (OHMS)
--- | ---
-40°C (-40°F) | 77k-109k
-29°C (-20°F | 39k-53k
-18°C (0°F) | 21k-27k
-7°C (20°F) | 11k-15k
4°C (40°F) | 6.6k-8.4k
16°C (60°F) | 3.9k-4.5k
27°C (80°F) | 2.4k-2.7k
38°C (100°F) | 1.5k-1.7k
49°C (120°F) | 0.98k-1.1k
60°C (140°F) | 650--730
72°C (160°F) | 430--480
83°C (180°F) | 302--334
94°C (200°F) | 215--235
105°C (220°F) | 159--172
120°C (248°F) | 104--113
140°C (284°F) | 63--68