Electronic Shift-On-The-Fly (ESOF) System

WARNING: This page is about a different car, the 2014 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

The Electronic Shift-On-The-Fly (ESOF) system consists of the following components:

Mode Select Switch (MSS), located on the instrument panel
Transfer Case Control Module (TCCM), located near the passenger kick panel
Integrated Wheel End (IWE) solenoid, located in left rear of the engine compartment
Integrated Wheel Ends (IWEs), located at each front wheel hub
Transfer case assembly (includes shift motor and synchronization clutch)

Vehicles equipped with an ESOF system allow the operator to choose between 2-Wheel Drive (2WD) (2H) and 2 different Four-Wheel Drive (4WD) modes. The transfer case is shifted electronically based on the MSS position. Under normal driving conditions, the transfer case is in 2WD (2H), but when desired, the operator may shift into 4WD high (4H) or 4WD low (4L). The operator can shift between 2WD (2H) and 4WD high (4H) at any speed. When shifting into or out of 4WD low (4L) range, the TCCM requires that the vehicle speed is less than 5 km/h (3 mph) and the transmission in NEUTRAL.

The transfer case is equipped with an electronically controlled clutch which is located inside the case. This clutch is used to synchronize the speed of the front driveline with the rear driveline during 2WD (2H) to 4WD high (4H) shifts.