EEC-IV (replaced by EEC-V) is Fords made and widely used engine control unit on years 83-99. Has been used from Ford Fiestas to Ford/Cosworth 1.5L turbo Formula 1 (year 1985). EEC-IV development can be seen from year 1986 document Equinox Turbo - The story of Fords first attempts at making a competitive turbo Formula 1 engine.
Year 1994(?) Escort Mk6 selling brochuser claimed that it has been too used on ZETEC-R Formula engines *.

+ Pics from development kits (Thanks Dex!)

There is many variations over the years like until year 87 (no catalysator) did not have KAM memory, year 92 came diagnostic port DCL, year 94 ignition module EDIS and later immobiliser PATS can be found included inside ECU.





For shortly how ECU functions..

Ignition Advance EEC-IV chooses from three different maps (Sea Level, Altitude or Borderline) the smalled advance reading (smallest HC ja NO -emissions). Idle spark is calculated with Spark Idle Feedback Desired Torque value from with MBT Spark table (Maximum Brake Torque - Fords highest ignition advance reference for stock engine) - map and it has low limit which for me was 3 degress as stock. I raised it up to 8 degress myself.
If you doing modifications you can simplify and remove all extra maps by putting in them very high Ignition Advance so ECU wont take notice of them ever as it always chooses lowest value.
Att! don't touch MBT Table - values.


EEC-IV fixes like all ECUs constantly gas air mix (Adaptive Control - Fuel Trim max 25%, aims for 14.64 AFR (Stoich) value) by conditions changing in Closed Loop.
To block learning cold or hot engine there is limits like for max and minimum limits for ACT and ECT sensors.
In Open Loop EEC-IV wont use HEGO sensor LAMBSE value (LAMBDA value which ECU asking) is calculated from Injection or Fuel maps.
In Closed Loop ECU constantly adds and lowers LAMBSE value until HEGO contorls the mix ratio right (fixes with injection pulse time length, which clacluates from MAF sensor) and saves the fix ratio multiplication to own map (which been used to make final value from Fuel Open Loop Stabilised Table) to KAM memory.


Does effect power and emissions if you have reset ECU by taking battery out for like 10min (KAM memory resets) as map is active under WOT throttle.

After reinstalling battery operation was descripted this in 2.0l DOHC Sierra '87 - Engine Management and Emission System -book:
After reconnection of the battery, the engine should be allowed to idle for 3 minutes. At normal operation temperature, engine speed should then be increased to 1200 rpm and maintained for approximately 2 minutes. This will allow the module to 're-learn' idle values. However, it may be necessary for the vehicle to be driven, allowing the module 're-learn' idle and drive values. The module should complete its learning strategy after approximately 5 miles (8 kilometres) of varied driving.
Previous learning can be notified after starting car when idle does swing around until Closed Loop has been reached and running does stabilise.

Failure Mode Effects Management aka FMEM effects when diagnostics notices one or more sensors being bad like ECT (Engine Coolant Temperature sensor) value goes over limits, so ECU replaces fully sensor value with fixed warm engine value. In this happening engine is bad start when cold as it wont inject the rich mix required under cold start.

Limited Operation Strategy aka LOS effects when all signals has been lost or battery is low (low level hw controlling takes place instead of microchip controll) and known as Limp mode. Can be notified ex. fuel pump humming constantly.

Lähde*

Car can be found OBD port but...
EEC-IV uses as protocol a SAE J1708 -By Steve.*Att! RS2000 ECU is more like a Sierra which does not have DLC port.*
EEC-V uses ISO 11519-4(SAE J1850 PWM) -fordclub.fi ja mustangforums.com.

More detailed explained here!

EEC-IV does not support standard OBD-II protocol commands.
"Ford's engineers decided to use a standard RS-485 -- two wire interface. Diagnosis is done by K-Line".

For diagnostics wanting one is ForDiag.
You can get too (if not found) installable OBD-port, which will be connected (pic) FD2000 service port (RS-485) wires, +12V and GND.

Kontakt -form and updates for program can be found here.
Package (Ceska posta -tracking) arrived 5 days in my local Postal office. Cost was 102EUR.


Att!
Cable and program is mainly made for Fords but can be used limited ways for VAG machines too. Cable (FTDI) can be put inside Fordiag to dummy mode or KL-mode, which then cable can be used with VAG-COM VCDS-Lite and ELMConfig * and Vol-FCR -programs. FD2000 service port can be found on Escorts which have Zetec near by air box (side of Vacuum Solenoid Valve) with red plug. Isntantly next to it is three pin FCR port (known as STAR).

Faultcodes via STAR port led light blinking has been separated in 1/2, 2, and 4 seconds stops. It can be read example like next:
(2-character codes like Sierras and RS2000) Fault codes
Fast codes (ingore them) KOEO codes (will be repeated twice)→ First digit of first KOEO code (1/2 second between blinks) 2 second pause Second digit of first KOEO code (1/2 second between blinks) 4 second pause Next KOEO code ... Once all KOEO codes are read the EEC will repeat them 6 second pause Single or Dual Separator Blink (this indicates the change from KOEO codes to stored codes from KAM) 6 second pause Codes from KAM memory (will be repeated twice) ...

(3 character codes like Escorts with Zetec) Faultcodes
Fast codes (ingore them) KOEO codes (will be repeated twice)→ First digit of first KOEO code (1/2 second between blinks) 2 second pause Second digit of first KOEO code (1/2 second between blinks) 2 second pause Third digit of first KOEO code (1/2 second between blinks) 4 second pause Next KOEO code ... Once all KOEO codes are read the EEC will repeat them 6 second pause Single Separator Blink (this indicates the change from KOEO codes to stored codes from KAM) 6 second pause Codes from KAM memory (will be repeated twice) ...

Chip?

J3 adapter

Ford Escort (EU) Zetec - GSAZ1 *Def* -WIP

TunerPRO forum i made own thread where from can be found download link my made of Definition files for these. Which can be used to modify values or parameters of these ECUs. If missing your ECU then send me *.bin -file of the ECU memory dump so i can disassemble it for you. Not maybe full but some.

If you end up disassemble yourself then search first MAF Transfer as its easiest. And notice next:
56K *.bin When Programing a EEC-IV use 56k Bin File from Address 2000-FFFF.

"Technical Notes on The EEC-IV MCU" (eectech98.pdf), revealed that 2020-2030 address alueella (2020=64K, 0020=56K *.bin) holds (Calibration Pointers / Table 'segment') addresses 8pcs. Which can be used to locate maps (goes in chain so earlier show next point) and shows else too..

EEC-V has these pointers at address 2062-2070.


Ford Mustang? Most liekly already disassembled. Get Binary Editor $170 and ready Definition $25-? for it.

Links for EEC-IV things:

EEC forums
"Technical Notes on The EEC-IV MCU"
"BPRacing - FAQ EECV Hardware Page"
"Pete Kvitek's EEC IV page"
"Andrew's EEC-IV pages" *.zip *
"DEEC - by Jason Keeney"
"A Semi Automatic Disassembler Tool -for 8061/8065"
"HAX Mk II programmer"
"T.I. Performance J3 Chips"
"Extreme Performance Engine Control - Handbook"
Fault Code Read:
From russia some sort Fordiag
FCR - "Key On Engine Off (KOEO) Testing Procedures "
FCR - "DIY Fault Code Reading for EEC IV units"
FCR - oldfuelinjection.com
FCR - "Error Codes and Fault Code Readers"
FCR - Gunson Ford FCR manual (Sierra, Escort, Cosworth... fault codes)
FCR - Do it Yourself LED code reader