For a complete wiring diagram Refer to Section 8W.The DTC is intended as an informational DTC to aid the technician in determining the root cause of a customer dirveability issue. The DTC is also intended to alert the technician to determine if a cooling system malfunction has occurred or if an additional transmission air to oil cooler is needed to support the customers driving behavior.When Monitored:Whenever the engine is running.Set Condition:Immediately after a Overheat shift schedule is activated when the Transmission temperature exceeds 127° C or 260° F.Possible CausesHIGH TEMPERATURE OPERATION ACTIVATEDTORQUE CONVERTER CLUTCH SLIPPING / NOT ACTIVATINGOPERATING VEHICLE WITH TRANSMISSION IN LIMP-IN MODE FOR AN EXTENDED PERIOD OF TIMEEXCESSIVE TIME IDLING IN GEARAlways perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE) 1. HIGH TEMPERATURE OPERATIONThis DTC is an informational DTC designed to aid the Technician in diagnosing shift quality complaints.This DTC indicates that the transmission has been operating in the "Overheat" shift schedule which may generate a customer complaint.The customer driving patterns may indicate the need for an additional transmission oil cooler.Verify proper Engine cooling system operation which would affect proper transmission operation.Verify proper torque converter clutch operation.With the scan tool, check the DTC EVENT DATA to help identify the conditions in which the DTC was set.If there are no possible causes remaining, view repair.RepairRepair the cause of transmission overheating. Refer to the Service Information for the proper repair procedure. Make sure to check for any Service Bulletins pertaining to this problem.Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)