Here is what 04 Diag manuals says about the code:
Symptom:
P0713-TRANS TEMP SENSOR VOLTAGE TOO HIGH
When Monitored and Set Condition:
P0713-TRANS TEMP SENSOR VOLTAGE TOO HIGH
When Monitored: Continuously with the key on and the engine running.
Set Condition: This code will set if the Transmission Temperature Sensor Signal circuit
voltage goes above 3. 76 volts for 2. 2 seconds.
POSSIBLE CAUSES
TRANS TEMP SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
TRANS TEMP SENSOR SIGNAL CIRCUIT SHORT TO 5-VOLT SUPPLY CIRCUIT
TRANS TEMP SENSOR SIGNAL CIRCUIT OPEN
SENSOR GROUND CIRCUIT OPEN
5 VOLT SUPPLY OPEN IN TRANSMISSION
TRANS TEMP SENSOR SIGNAL CIRCUIT SHORT TO 5-VOLT SUPPLY CIRCUIT INSIDE TRANS
TRANS TEMP SENSOR SIGNAL CIRCUIT OPEN INSIDE TRANS
SENSOR GROUND CIRCUIT OPEN INSIDE TRANS
TRANSMISSION TEMPERATURE SENSOR
ENGINE CONTROL MODULE
INTERMITTENT WIRING AND CONNECTORS