A/T - E4OD Description
SIL 89-28 (Aug)SUBJECT: FORD
INTRODUCTION
The E40D is a fully automatic, computer-controlled, four-speed transmission. It is currently used in 1989 Econoline and F-series trucks, but will be in Bronco 5 and motor homes at a later date.
The main operating components of the E40D include a torque converter clutch, six multiple-disc clutch packs, one band, two sprags and a one-way roller clutch.
The operation of the E40D is controlled through the EEC-IV system for gasoline engines, or the transmission control system for diesel engines. Many electronic components provide information that affects transmission operation. The components for the gas engine include the following:
^ Throttle position sensor (TPS)
^ Manifold absolute pressure (MAP) sensor
^ Profile ignition pickup (PIP) signal
^ Brake switch
^ Manual lever position sensor
^ Vehicle speed sensor (VSS)
^ Transmission oil temperature (TOT) sensor
^ Overdrive cancel switch and indicator light
Transmission operation is controlled through four (4) on/off solenoids and one (1) variable Force Solenoid (VFS). These solenoids are housed in the transmission solenoid body assembly. Solenoids 1 and 2 provide gear selection of first through fourth gears. Solenoid 3 controls the torque converter clutch (lock-up). Solenoid 4 controls the coast clutch for overdrive lock out and engine braking. The VFS combines a solenoid and a regulating valve to produce Electronic Pressure Control (EPC) which regulates transmission line pressure.
Solenoids 1 through 4 are normally closed, blocking the flow of fluid. When the solenoid is on (energized) it allows pressure to flow through it, operating the shift valves. The following charts show solenoid operation for the various shift selector positions, and major components used in each gear.
The chart (Fig. 1) shows solenoid 1 through 4 applications for the various shift selector positions.
The chart (Fig. 2) details the major components that are used during each gear. The chart reflects both drive and coast.