Ford EEC-IV wiring (1993 Mondeo, Zetec 2.0)
 

I plan on running Zetec 2.0 with the standard engine loom and stock engine management. On various forums the Ford EEC-IV is complimented as being smart enough to be useful and practical, but simple enough not to cause too much trouble.

As it's been a bit too cold to spend time in the workshop, I've been spending time sorting out the looms I have in the warmth of my home. Broke a Mondeo and a Sierra loom for wires and plugs, also tracked down each wire and plug within the Mondeo Zetec harness. Now I have spreadsheet of the ECU pinout with colours and functions, and a tag on each wire coming into the three oval plugs that connect the engine loom to the body loom:

https://fridge.pov.lt/~alga/zetec/Mondeo-ECU-pinout.pdf
(editable spreadsheet version)

My engine management has the coil drivers built into the ECU, systems with EDIS-4 might have slight differences in the ignition wiring.

To summarize, you just need to feed battery positive, main power positive, ignition positive, and battery negative in order to run the engine with the stock ECU. The rest of the wires coming out of the engine loom are various senders and non-essential sensors and outputs. There isn't even a check engine light coming out of that ECU!

Removing EGR, pulse air and canister purge relays/sensors from the system might upset the ECU (codes will be visible in the self test), but they should not throw it into limp mode. If they cause any problems, they can be stubbed with appropriate resistors.

If you decide to go this route, I recommend getting the Haynes manual for the engine donor. The Mondeo's Haynes wiring diagrams are much easier to read than Sierra's, as they have all the numbered components listed on the same page. If you don't want to buy a paper version, for Mondeo, usually googling for 1923-12.PDF will do the trick!

Speaking of wiring, the injector/CMP/temp sensor subharness was completely Kaput on my engine. Out of 12 wires in that subharness there wasn't a single one with isolation fully intact. I suspect the engine wiring was the main reason why the Mondeo was broken:




The main part of the engine harness is in a pretty good shape. Only the crank angle sensor wires and the EGR valve plug wires are damaged. EGR will be deleted anyway, and the CKP plug I replaced.

I found out that the square plugs used for injectors and most sensors on the Zetec are of the Tyco/AMP Junior Power Timer series. Getting replacement crimped contacts for them will not be much problem.



But I've still no clue what the oval 12-point plug is called. In the worst case I'll solder the wires to the old contacts.

Hi Albert. I'm going the same way. Have you figured out if removing the purge,egr and pulse upsets the running at all? I'm using a DEEP Ecu which has the inbuilt Edis

If you need to replace just the pins in the plug itself rather than solder the wires on to short tails these people are most likely to have them.

http://www.vehicle-wiring-products.e...e/homepage.php

And if you need the tool for getting the critters out snap on do this and its not dear to buy, i have had mine years and its had a lot of use.

http://directory.pten.com/product/10...et_No_SGTT106A

Bob

Oooh, thanks a lot for the pointers. I was going to get the contacts from the generic electronics suppliers like Digikey or Farnell. JPT terminals are widely available, but the 1.6 mm round pin system of the oval plug appears to be quite rare.

As for deleting pluse air, canister purge and EGR sensors & valves, I haven't been able to try it out yet.

No you will be fine with out these and more besides. Such as the air con presure switches and other load adjusters like the heated windows and clutch.

It also runs fine with out the speed sensor But I do plan on refitting that as there are meant to be other gains such as fuel cut on over run ect.

Dont limit your self to the early eec-iv as the Pat's is no big deal as long as you have the matching key and you gain the obd2 function.

Ive done several and had one I did through iva

Pre 95 deep ecu

http://youtu.be/Pxq4ks2Us_U

Post 95 (1997)104 pin eec-v with Pats owls ecu

http://youtu.be/BKqeCjdBM0w

1999 104 pin eec-v with pats Olw5 ecu. This was wired for a midi and shows how few connections there are. Done so the user only had perm live switched live, a few earths, fuel pump and there is one for the tacho.

http://youtu.be/pUbV0NPvx4M

Some really usefull information there Big W :) :cool:

So, I have got the engine wired and running with the stock ECU. Some notes:

* I'm using an LED with a resistor to read error codes on the STAR connector. I made a plug to connect to the triangular STAR socket by pulling out the terminals out of a similar plug and inserting them into a triangular male plug which was used to blank one of the unused plugs on the engine harness, speed sensor or somethinlg like that.

All the removed systems (Pulse Air, EGR, Power Steering valve) are ringing error codes in the STAR connector. They are a bit annoying as you have to read them all slowly just to see if there are any other codes. I'm not sure if it's worth silencing these errors by adding resistors where needed. Fuel pump relay code is also signalled. Probably the ECU expects the pump to stop after building out the pressure when the engine is not running, mine is always running when ignition is on.

* The tach signal is 12V positive pulses 1 ms in duration. Sierra's tach expected a coil signal, with negative pulses from 12V to 0, and didn't work with the ECU signal. I made a logic inverter out of a MOSFET, now the tach works. I can post the schematics if anyone is interested.

* The radiator fan control signal is grounded for off, disconnected from ground for on. So, another MOSFET is needed to drive the fan relay, or a normally closed relay. Or an original transistor fan relay out of a Mondeo.

* The engine tends to foul plugs, from time to time one of the cylinders refuses to fire due to no spark. Might be old sparkplugs, or the engine might be running rich at idle. I think the ECU relies on EGR at idle speeds. I haven't gotten around to checking the oxygen sensor yet.

Missed this last year.

The oval plug is a ford specific plug.


I must try and get my blacktop running, I have an ecu which I think is PATS free but it's over a year since I looked at it.

TT

I found the female terminals for the oval Ford plug at Würth. They came with pieces of red wire and silicone seals already crimped on, ready for soldering, and they cost something like 40p apiece (eek!)