Driving Your Aerostar - Ford 1996 Aerostar Manual

Driving Your Aerostar

Automatic Transmission
Operation (4R44E/4R55E)
The 4R44E and 4R55E transmissions are
electronically controlled four speed overdrive
automatic transmissions with lockup torque
converter. Transmission operation is controlled
by the Powertrain Control Module (PCM).
The PCM will automatically adjust transmission
operation to make up for varying conditions.
Several sensors located on the engine and
transmission such as throttle position, engine
speed, vehicle speed and transmission
temperature are used by the PCM to shift the
transmission into a higher or lower gear when
required for the best performance and fuel
economy. For example, you may notice that the
transmission will upshift to a higher gear more
quickly when the vehicle has not reached normal
operating temperature.
The PCM also controls the transmission's Torque
Converter Clutch (TCC) to further raise vehicle
performance and fuel economy. The TCC will
engage when the transmission operating
temperature and other conditions determined by
the PCM have been met. Engagement of the
clutch may be noted as a decrease in engine
speed.
To help in troubleshooting, the PCM continually
performs self-tests on the electronic control
system and, if any faults are detected, stores
them in memory. The Overdrive Off Indicator
Light (O/D OFF), which is located on the
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