Ford EEC
The Ford EEC or Electronic Engine Control is a series of ECU that was designed and built by Ford Motor Company. The first system, EEC I, used processors and components developed by Toshiba in 1973. It began production in 1974, and went into mass production in 1975. It subsequently went through several model iterations.
EEC I and II
The EEC I and EEC II modules used a common processor and memory so they can be described together. The microprocessor was a 12-bit central processing unit manufactured by Toshiba, the TLCS-12, which began development in 1971 and was completed in 1973. It was a 32mm² chip with about 2,800 silicon gates, manufactured on a 6 μm process. The system's semiconductor memory included 512-bit RAM, 2kb ROM and 2kb EPROM. The system began production in 1974, and went into mass production in 1975.The EEC-II controlled air-fuel ratio via Ford's model 7200 Variable Venturi Carburetor, the last carburetor designed and built by Ford US. In it, the air-fuel ratio was controlled by a stepper motor that operated a rack which moved a pintle that opened and closed the float bowl vent. When closed, no air could enter the bowl, causing the fuel mixture to be lean. When open, the fuel mixture was rich. Each carburetor was hand-calibrated in a pressure-controlled room.
EEC-III
This system was used on certain 1980-83 vehicles. There were two different EEC-III modules; one for use with a feedback carburetor, and one for use with Ford's "Central" throttle-body fuel injection system. The module size and shape were approximately the same as the EEC-II and still utilized the external memory module. The two modules had differently keyed connectors to prevent accidental insertion in the wrong vehicle.EEC-III uses a Duraspark III module and a Duraspark II ignition coil. A resistance wire is used in the primary circuit. The distributors in EEC-III systems eliminate conventional mechanical and vacuum advance mechanisms. All timing is controlled by the engine computer, which is capable of firing the spark plug at any point within a 50-degree range depending on calibration. This increased spark capability requires greater separation of adjacent distributor cap electrodes to prevent cross-fire, resulting in a large-diameter distributor cap.
EEC-III on carbureted cars controlled the same Ford 7200 VV carburetor as the EEC-II. On fuel-injected cars, the module fired two high pressure fuel injectors that were mounted in a throttle body attached to a traditional intake manifold in the center valley of the 5.0 liter engine.
The processor was designed and manufactured by Motorola. It featured an 8-bit data length, a 10-bit instruction length and a 13-bit address length. The address space was "paged", meaning you could not directly address all of the address space without special instructions. There were 4 pages. Page 0 was for normal code. Page 1 was for interrupt code. Page 2 was also for background, but could only be accessed by a special "Jump Page" instruction from page 0. Page 3 was used to store parametric data or additional interrupt level code. This chip was never sold commercially. Like EEC-I and -II, all code was written in assembly language.
The processor chips were manufactured by Motorola, and the modules were designed and assembled by Motorola, Toshiba, or Ford. The designs were functionally equivalent but slightly different components were used. Motorola optimized their design to use as many of their own components as possible.
EEC-IV
Preliminary design work in EEC-IV started even before EEC-III was in production. Over time, there were many different modules designed around this processor. It is likely that more Ford vehicles were produced using Engine/Powertrain Control Modules based on variations of this design than any other module that Ford has ever used.Unlike previous EEC systems, EEC-IV uses a small ignition module called the TFI or TFI-IV module. It is usually grey in color and was originally mounted on the distributor. Later models have the TFI module mounted on a heatsink in the engine compartment. It is prone to damage from heat. It was created with surface-mount technology parts, allowing it to be much smaller than the previous Dura-Spark ignition module. The ignition coil used is the E-Core design. This ignition coil design is more efficient than the older-style cylinder-shaped ignition coils.
The EEC-IV system has more diagnostic capabilities than previous EEC systems. Early EEC-IV equipped cars don't have the capability to send sensor data through the diagnostic connector to a scan tool. However, there are KOEO and KOER self-tests, and a continuous-monitor test, a feature to help test the wiring connections to various sensors/actuators by wiggling the wires of the component in question. By the early 1990s certain models had sensor data streaming capability called DCL.
The EEC-IV computer was built around an Intel-designed 8/16 bit processor called the 8061. This chip was never sold commercially, but a close variation, the 8096, was extremely popular. The major difference between these two chips was the external instruction/data bus. Ford wanted to minimize the number of pins used for input and output so Intel designed a unique bus that multiplexed address and data onto an 8 bit bus. Several additional control lines were used for transferring information on this bus. Because of the unique nature of the bus, custom memory chips were required.
EEC-IV first appeared on the 1983-1/2 1.6L Escort EFI. This was followed in 1984 2.3L High Swirl Combustion, 2.3L EFI Turbo and 2.8L truck engines. With the Escort, the base engine was the same as all US Escorts, the 1.6L CVH, but featured unique intake and exhaust manifolds in addition to EFI. This was non-sequential EFI, meaning 1/4 of the required fuel for each cylinder was injected into the intake manifold, near the intake valve for each cylinder firing.
The first EEC-IV module was different from future modules. It had a unique "edge card" connector intended to reduce cost versus the EEC I/II/II pin-and-socket connectors, but was quickly abandoned due to poor reliability. It utilized a 40 pin DIP IC package which limited the number of inputs/outputs. It also used only 1 memory chip which contained 8K bytes of MROM instructions/data and 128 addition bytes of RAM.
All subsequent EEC-IV modules used a through-hole IC package with staggered pins on all 4 edges which allowed all available I/O to be utilized. Memory quickly grew to 2 - 8k/128 MROM/RAM chips and then a separate 32K MROM and 1K RAM. Bus loading limited the design to 2 external memory devices.
Intel only manufactured chips, not modules. Eventually there was a unique MBUS UVEPROM designed and manufactured by Intel. Motorola and Ford Electronics Division designed and manufactured the modules. After several years of Intel being the sole supplier of processor chips, Ford persuaded Intel to share the design with Motorola and allow them to produce 8061 chips, but only for consumption by Ford.
Over the years, there were many variations of EEC-IV modules depending on the number of engine cylinders and the types and quantities of inputs and outputs. There were even a series of special EEC-IV modules designed for use in Formula 1 race cars, making Ford one of the earliest adopters of digital electronics on a race car.
These EEC-IV were used on the Ford/Cosworth 1.5L turbo Formula 1 engine in 1985.
This engine with the EEC-IV was used by Haas/FORCE F1 a.k.a. Hass/Lola. This team employed both Ross Brawn and Adrian Newey.