E059

ECM Code E059:

DFI Sensor Circuit:

DESCRIPTION:

The transmission temperature sensor is a thermistor, or variable resistor, that varies in resistance based on temperature. The sensor is a two wire sensor with a reference signal coming from the ECM to the sensor on Pin A (CKT 520) and a reference ground on Pin B (CKT 476). As the temperature of the sensor increases, sensor resistance decreases. As the resistance decreases, the signal voltage from the ECM decreases due to the less voltage drop across the transmission temperature sensor. High temperature will result in low signal voltage on CKT 520 and low temperature will result in high signal voltage on CKT 520. The ECM uses transmission temperature information to vary VCC apply speeds. Code E059 will set the ECM sees a excessively low or excessively high VCC temperature when the coolant is hot or cold, respectively.

TEST CONDITIONS:

1. Codes EO14 and EO15 not set.
2. Vehicle speed greater than 10 MPH for 600 seconds.

FAILURE CONDITIONS:

Transmission temperature less than -39°C when the coolant temp is greater than 50°C or transmission temperature greater than 148°C when the coolant temp is less than 50°C.

ACTION TAKEN:

1. ECM turns on "SERVICE ENGINE SOON" telltale.
2. ECM commands BCM to display "SERVICE SOON" message on DIC.
3. ECM substitutes 11O°C for transmission temperature.

NOTES ON FAULT TREE:

1. VCC sensor circuit is shorted to ground.

2. VCC sensor circuit is open.

NOTE ON INTERMITTENTS:

Manipulate the transmission connector, ECM connector, and CKT 520 wiring while observing ECM parameter ED26. If the fault is induced, the data value will jump from a normal reading to a low or high reading. Repair the intermittent short to ground or open in CKT 520. Disconnect and reconnect the ECM and transmission connectors and ensure they are latched. If wiring and connectors check out OK, substitute a known good transmission temperature sensor and retest.

Review the snapshot data parameters stored with this code to verify failure condition. If the failure condition is verified, check and repair intermittent wiring connection, or sensor.