Code 59, Transmission Temperature Sensor Low Temperature: Notes

Temperature sensor is a 2 wire thermistor located in transaxle. This sensor operates in the same manner as engine coolant temperature sensor and intake air temperature sensor. PCM applies 5 volts to sensor on signal circuit. Voltage sensed at PCM signal circuit terminal will be high when trans fluid is cold and as fluid warms voltage signal will drop. A very high signal voltage indicates a low fluid temperature or a failure in sensor circuit. Normal fluid temperature range is between 167°F-212°F (75°C-100°C).

Code 59 will set when sensor indicates a temperature of less than -40°C for 5 seconds. Malfunction Indicator Light (MIL) will not illuminate and PCM will use a default sensor value of 90°C.

1. This test determines if a current condition exists.
2. Simulates a Code 58. If PCM recognizes low signal voltage, and scan displays 146 degrees centigrade or higher, PCM and wiring are okay.
3. Checks if signal circuit is open. Five volts should be present at sensor connector.