FORD FCSD TECHNICAL TRAINING FCS-14000-DL - Manual (Page 93)

LESSON 3: POWERTRAIN
Sensors Integrated With TCM
Sensors Integrated With TCM
Item Description Item Description
1 Output Shaft Speed (OSS) Sensor 3 Turbine Shaft Speed (TSS) Sensor
2 Transmission Fluid Temperature (TFT)
Sensor
• Several sensors are located on the TCM and main control valve body unit.
• The Turbine Shaft Speed (TSS) sensor is a Hall effect type sensor.
• The Output Shaft Speed (OSS) sensor is a Hall effect type sensor.
• The Transmission Fluid Temperature (TFT) sensor is a temperature dependent resister (thermister).
– The TCM uses the TFT signal to determine whether a cold start shift schedule is necessary. The cold start
shift schedule allows quicker shifts when the transmission fluid temperature is cold. The TCM also inhibits
torque converter clutch operation at low transmission fluid temperatures.
The TCM can diagnose electrical errors associated with the TSS and OSS sensors while the vehicle is stationary
as well as moving. Plausability monitoring is carried out on the sensor output when the engine is running.
2005 Expedition/Navigator New Model Technician Training 02-SEP-04 3-57