How to install a Dodge SMEC (single module engine controller) into a Ford 2.3 turbo powered vehicle

Okay, first off a list of items that you well need to gather on your next trip to the junkyard.
1) The SMEC itself.
You need to locate any 88-89 turbo chrysler product. This shouldnt be hard, since Chryco put turbos in EVERYTHING in the 80s. Anything from a Dodge Caravan to a K-car, Daytona, Laser, Aires, LeBaron, etc will do. If you are unsure of year, it is very easy to tell by looking at the ECU itself, which is located near the driver's side fender behind the headlight. The SMEC is easily identifiable by its 60-way and 14-way connectors; no other dodge ecu has this configuration.

2) The wiring harness.
Many times this can come from the same vehicle that the SMEC above did, however some are less desirable than others. In particular, some are routed through the firewall and some simply pass along it in the engine compartment. Naturally, the one routed through the firewall should be avoided, as it is very hard to extract. Once you find a suitable donor, get out your wire cutters and go to town. Start by disconnecting all sensors and connectors that you can get to. Then, cut the harness where it enters the firewall. It is very thick here, so some kind of a saw may work better than wire cutters. Cut the harness loose from its mounting as you go around the engine bay, making sure to retain mating connectors wherever possible. Cut the wires leading into the headlight/bumper area on each side, as these just go to the lights and are not required. There are several relays attached that should also be retained. Don't forget the injector harness, as it does unplug from the main harness just like the Ford ones.
3) Sensors.
You will need to grab the following sensors: coolant temperature, oxygen sensor, knock sensor (if you choose to use one), map sensor/baro-read assembly, and charge temperature sensor. If you are lucky, you found a Turbo II setup that already has a charge temp sensor, but most will have to scrounge one off another vehicle (any year turbo car will work). The coolant temp and charge temp sensors are electrically identical, but physically the coolant temp has a brass body while the charge temp is plastic. Here is a picture comparing the two, and pictures of stock locations of the sensors:
**example pics here**
For the oxygen sensor, you could buy a new one from the parts store if you want, but they are expensive. the SMEC ustilizes a 4 wire heated sensor with external signal return, unlike the 1 and 3 wire Ford sensors. They do share the same thread size though so are completely interchangable. A hint for lossening the sensors: hit the base of the sensor with a small hammer to break the rust loose. After this small tap, many sensors can be unscrewed by hand with no other tools required. The SMEC also relies on a speed sensor for various functions such as dashpotting and cruise control. Using one is not required, however the car will tend to idle down too soon when decelerating and may die easily at stop lights. Those with transmissions from 87-88 thunderbirds that have a speed sensor on the tranny will be able to use the signal from that sensor as it is compatible. Others will have to add the sensor or do without.
4) Throttle body.
Most will want to pass up the 4 cyl Dodge turbo throttle bodies as they are only 48 mm. However, 3.3L V6 Caravans have a compatible 52 mm throttle body (same size as the stock Ford unit). Or a 58 mm or larger tb can be sourced from 3.8L Caravan engines or other mopar products. I am still working on sources for these larger throttle bodies. If being used on a race car or other application where idle control is not important, any throttle body that incorporates a 5v max output tps can be utilized; the SMEC is smart enough to adapt to just about any tps. However, it can only control a stock type stepper motor for idle control, not the linear actuator type as used on Ford engines.
**picture of 52 mm tb here**
5) Distributor.
UPDATE
I have recently completed a long standing modification of the SMEC code to make it compatible with a stock Ford distributor! This means that the following distributor instructions are no longer required. I will post the wiring required to hook into the TFI soon, as well as the modified code file. At this point it would also not be a good idea to use a knock sensor with this modification. This will be fixed in the future if there is enough interest.

This one gets a bit tricky. You will ned 2 distributors: the one from the same car you got the harness or SMEC from will work for the Dodge side, and you will also need a Ford 2.3 distributor. These two will be cut apart and welded back together to make a hybrid distributor. The details for this will be given below. If you will be making your own spark plug wires, you will also want to clip off the distributor ends of the spark plug wires, or just grab the whole set.
Dodge Distributor:


Now on to the build.
First the details on the distributor, as machine work will be required and we can speed things along by getting it to the machine shop right away to be worked on while we do up the harness. Note that i have seen two different styles of Ford distrubutor, and that only one type may work.
Here is a crude ascii drawing of how the distributor shaft needs to be machined (this is the ford shaft, no part of the dodge shaft is used). 

         6.110"
     |--------------------|  1.500"
                          |---------|
            / /
+-///------/ /------------+
| ///      \ \            |----------  - dia .452"
| ///       \ \           |----------  -
+-///-------/ /-----------+
           / /
you can see the finished shaft in this picture:

Note on the drawing that there also needs to be a keyway cut at the top end for the rotor, and a hole drilled in the middle for a roll pin to secure the stator cup. The stator cup should be pushed all the way onto the shaft so that the bottom of it rests on the should of the transition in size. It is absolutely essential that these are lined up correctly with each other, so that the rotor points at the leading edge of the stator vane with the window in it. Examine the dodge distributor before taking it apart to see how this lines up.
Now to cut the distributor bodies. The dodge distributor is easiest; once the shaft is removed, it just needs to be cut at the base where it is square such that you are left with the cup shaped upper half. Make sure to cut as straight as possible, and clean it up with a file afterwards. This becomes the surface that is mated to the Ford distributor, so must be absolutely flat and true to ensure that the final product is true.

Now cut the "walls" of the cup off the ford distributor so that you are left with just the flat bottom surface. Again, be carefull with the saw here, as this is the other mating surface.

Next the bottom of the Dodge half will have to be drilled out to the same size as the center bushing of the Ford distributor. Be absolutely sure that you have the drill exactly centered, as this will be the only thing keeping the halves centered in the next step. The use of a drill press here is highly advised. Before welding the two halves together, the center bushing should be cut down flush with the inner surface of the dodge part of the distributor. Now its time for the welding. Simply slip the two distributor halves together and weld all the way around the outside. The pieces should sit level and centered if the above steps were followed correctly, so you wont need expensive machine shop equipment to do this step. A cheap mig welder has been used successfully for welding these together, and even a metal epoxy like JB Weld may work. Now, put it all back together, using roll pins from your local hardware store if you need new ones.
Here is the final product:

That concludes the distributor construction.

You will have undoubtedly noticed by now that normal Ford spark plug wires do not have the correct distributor ends on them, and that the stock Dodge ones are not nearly long enough. So, we are left with the option of buying new custom wires from Magencor (at $100 or better), or constructing our own. Probably the cheapest option would be to buy a new set of Ford wires and re-crimp the Dodge ends that you grabbed from the junkyard along with your distributor. It's a tough job, but its the cheapest route.
Now comes the longest and most tedious process, preparation of the wiring harness. To start with, you will become very familiar with the images on this page, the scans of the engine harness diagram. It would be wise to print these out as you will refer to them often. The first task is to strip the harness of all its wire loom and electrical tape. This is a very messy process, as the harness is covered with deteriorating electrical tape as well as many harnesses being soaked in oil and grease. Sometime during this stage you will want to pry out the red inserts in the 60-way connector and remove the wires that will not be used. Be carefull while the red retaining inserts are out, as the wires can come loose very easily, which could make for a nice puzzle to put back together. Here are some wires that i have identified as not being required. Naturally, some may wish to keep some sets of wires for various features such as cruise control.
pins 7, 8, 9, 29, 53, and 60 can be removed if not using the built-in cruise control.
pins 45 and 56 can be removed if not using a/c.
pins 2, 30, 36, 39, 40, 48, 54, 55, 57, and 59 can be removed or left in as desired. refer to the pinout diagram for their functions to determine if you will require them.
If there is not a wire at location 21, you will need to add it in (this is for the charge temperature sensor). This is very easy to do, simply drill out the gray plastic body with the correct size drill bit, remove the plastic nipple that is left over, and insert one of the wires that were removed above.
Now we will have to relocate many of the sensor's plugs, as the Ford engine bay layout is very different from that of the Dodge. You will have to start by determining where the SMEC itself will be mounted. Often it will be alot easier to mount of the housing is cut down to size. Although it was cooled by the intake air passing through it in the Dodge, this is not neccessary and so opens up more placement options. In My Merkur I mounted it in the location previously occupied by the battery after the battery was relocated to the trunk. Find a suitable location for the SMEC, and then measure out along the intended path of the harness to where each sensor harness will branch off. Now dig into the harness, cutting or extending wires where needed to move the sensors into locations that math your measurements from above.
My harness ended up being laid out as such:
    (8)
     |  F I R E W A L L
SMEC-+-+--+-----+-----+-----+
       |  |  v   |     |     |
       | (3) a   |     |    (1)
      (2)    l   |     |
             v   |     |
             e   |     |
                (4)    |
             c   |    (9)
             o  (5)    |
             v   |    (6)
             e  (7)
             r
as seen in this picture:

legend:
1) MAP sensor and baro-read solenoid assembly
2) O2 sensor
3) Engine coolant temperature sensor (in heater supply line)
4) Injector harness
5) Throttle body connections (TPS and idle motor)
6) Ignition coil
7) Charge temperature (mounted in intake)
8) Interface connector (power, instrumentation, etc)
9) Distributor pickup
As noted at point (8), a single multi-position connector was used to route power to the system, and route signals out for instrumentation and fuel pump control. The connector used in this case was the one used for the vehicle speed sensor (among other things) in the Dodge, since the speed sensor only used up 2 pins of the 8 available. In addidtion to the speed sensor, I utilized the other 6 positions for battery power, key-on power, tach signal, fuel pump relay signal, oxygen sensor output (for a/f meter), and fuel monitor output (for experimenting with the in dash econo module used in some Dodge vehicles). It is interesting to note that the only ground used in the system is in the injector harness and utilizes one of the fuel rail bolts.
**did i miss anything?**

Links and resources.
mailing lists:
Mopar_ChEM. A public group dedicated to the ChEM calibration tuning software.
Mopar_ECM. This is a private group those with the skills and background to be able to hack and reverse engineer the various Mopar ECUs.
Links:
ChEM. One of the best pieces of software I have seen for tuning ECU programs, and best of all it is free!
D-Cal. D-Cal is a very promising calibration tuning program still in developement, but holds some special interest to us, as it is more tailored to SMEC hacking than ChEM is. Get it from the files section of this yahoo group
Russ Knize An excellent (if brief) site with some general background info on ChEM and D-Cal, and with links to sources of some of the harder to find and unique parts used by the ECU hacker.

 

THANKS TO : xrattiracer
his home page