FORD FCSD TECHNICAL TRAINING FCS-14000-DL - Manual (Page 96)

LESSON 3: POWERTRAIN
TCM Monitoring Functions
The TCM monitors all transmission inputs and outputs to identify possible transmission failures. If a fault is
detected, the TCM takes the appropriate actions to ensure the transmission enters a safe mode of operations. The
PCM then sets a DTC and illuminates the Malfunction Indicator Lamp (MIL).
•
Voltage Supply - This function monitors the vehicle’s battery life.
• Watchdog Monitoring - This feature has two functions:
– Checks for faults in the driver circuits by activating each driver.
– Checks to see if the safety circuit is functioning correctly.
• TCM Temperature - If the TCM temperature raises above a predetermined level, the TCM shuts down. Prior
to shutting down, the TCM logs a fault code during the shut down. The transmission enters a mechanical limp
home mode.
• Pressure Regulator/Solenoid - Each pressure regulator and solenoid is monitored for open and short circuits.
The TCM also checks that the current being delivered to each solenoid valve or pressure regulator is within
limits.
• Torque Converter Control - The TCM checks and verifies that the torque converter has been engaged
correctly. If the torque converter has not engaged correctly, the TCM will carry out the fail-safe action of
opening the converter clutch.
2005 Expedition/Navigator New Model Technician Training 02-SEP-04 3-60