Ford EEC
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.
[1][2] Ford's internal code name for the TLCS-12 microprocessor was "PM-11" or "Poor Man's 11" implying it was a stripped down version of the, then popular, Digital Equipment Corporation PDP-11 computer.
[citation needed] This 12 bit processor was the only commercially available chip to feature all four mathematical functions (addition, subtraction, multiplication and division) at the time.
This was done to facilitate changing the software, a combination of algorithms ("strategy") and data ("calibration") in the field, if necessary.
The strategy would read these switches and retard the spark advance for vehicles experiencing pre-ignition (knock).
[citation needed] The processor module featured a 10 volt reference for its analog-to-digital converter which was used to gather data from various sensors.
First, all sensors used a ratiometric measuring method that ensured accuracy in spite of varying reference voltage.
Second, during cranking, a special circuit triggered the ignition system in synchronization with the reference pulses from the engine.
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.
[3] Although there was much in common "inside the box", the size, shape and main connector were different between EEC I and II.
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 two modules had differently keyed connectors to prevent accidental insertion in the wrong vehicle.
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.
On fuel-injected cars, the module fired two high pressure (approximately 40 psi) fuel injectors that were mounted in a throttle body attached to a traditional intake manifold in the center valley of the 5.0 liter (302 cid) engine.
Page 3 was used to store parametric ("calibration") data or additional interrupt level code.
It was created with surface-mount technology parts, allowing it to be much smaller than the previous Dura-Spark ignition module.
Early EEC-IV equipped cars don't have the capability to send sensor data through the diagnostic connector to a scan tool.
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.
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.
Additional performance needs drove Ford Electronics to develop an enhanced microprocessor named the 8065 building on EEC-IV technology.
Additional interrupts and improved time controlled I/O allowed continued use of EEC-IV code and extended the family lifetime to almost 20 years in production.
European Ford Diesel Duratorq engines (all TDDi and TDCi starting with model year 2000) used EEC-V DPC-xxx series, which used variant of Intel i196 microcontroller with 28F200 flash memory.
[6] EEC-150 for 3.0/4.0 V6/4.6 SOHC engines uses PowerPC, however compared to Visteon Levanta the ECU is closer to EEC-VI by design.
