I was reading through the mr2 message boards on megasquirting the 2, and I came across this post http://www.mr2oc.com/showthread.php?...1&page=1&pp=30

which lead me to these pictures

look farmilliar?


The yellow one is the exact same looking connector as my s5 unit, as I am sure most of you have noticed. To the ones who have yet to see an s5 unit i have pics coming tomorrow.

The brown connector is an odb1 connector for a pretty long list of cars:
http://tuner-deals.com/-p-22.html?ze...b1ce704d15223c
It looks like it can also be used for a s5 breakout board. You will just have one extra unused connector socket.

So far, from what i see, it looks like the s5 ecu works with a MKII gen2/3 mr2.

Lets take a closer look shall we:



pics are from here: http://www.mr2oc.com/showthread.php?t=157628

Seems close enough to me to bite the bullet. I am going to go ahead and order the 3SGTE breakout board. When i get it I will let you know how it works out.
The place to buy them:
http://tuner-deals.com/-p-21:634f0ef...b1ce704d15223c
http://tuner-deals.com/-p-22.html?ze...b1ce704d15223c

The pinout labels on the break out boards differ from the s5 ecu pinout, so the board silkscreens will not match the rx-7... which can prove confusing to some. Much of the jumpers will not help, and theres a pretty high chance of having to re-route some of the signals.

However, finding extra connectors should not be that hard either. It seems that many honda ecus also have the same connector type. Though i have yet to see it with my own eyes. http://www.mr2oc.com/showthread.php?...hlight=hondata

 

Here are a couple pics of my extra s5 n/a ECU.

 

I actually have an adapter board that's waiting for test. Hopefully I'll have time to test it sometime in the next couple of weeks.

Ken

 

I was planning on making my own either way. This was just an unexpected finding, so i thought i would share... For the impatient people who dont mind doing a little bit of extra work.

I could use the s5 n/a stock base maps though.

 

That should work if the adaptor board "high load" (power/ground/injector) thicker pins/traces went to the corresponding "high load"pins of the S5 yellow connector.If that's the same connector (which it looks to be) then that should be the case as the thicker power/ground/injector pins on the S5 connector would be the same ones used by the MR2.Do you know if that's the case?

 

The connectors are the same, and the traces are thicker for the "high load" pins.
ninjai is going to use the 3S board, he will most likely have to do a small amount of re-pinning.
There is also a "generic" board, it uses a 76-pin connector but the RX7 harness will plug into 64 pins of it. The closeout-priced generic board is a straight breakout board. Not yet listed on the site, there is a second version (of each board), that includes much MS2E circuitry --

• 2 programmable outputs
• Table switching
• Launch Control
• One VR conditioning circuit
• A PWM boost-solenoid control circuit.

Oh yeah, there is a knock headphone circuit on board as well, for tuning purposes (or if you like to listen to your engine...).

 

Even if the 3s board did not come with thicker traces for the pwr/gnd/injector, its easy to rework it and just use 18 awg or thicker wire for them. Especially since all the traces seem accessible due to the fact its a 2 layer. Simple cut/rewire and you are good to go.

Once I map out the differences between the rx-7 and mr2 connectors ill post it up.

 

Here are the pinout comparison. Could somebody please overlook the rx-7 pin out diagram. I need confirmation that its correct. The bold items are the ones That are not used with the megasquirt. Something tells me I am missing a couple.

The rx-7 list below is set up so that the The pinout follows the pin labeling on the mr2. Let me know if there is something wring/missing.

pin# s5 13b
1A battery
1C ignition switch
1E malfunction indicator light (MIL)
1G ignition coil trailing (Igt-T)
1I 1 pin test connector
1K fuel pump resistor relay
1M mileage sensor
1O a/c switch
1Q Clutch switch
1S fog light switch
1U AT switch
1B main relay
1D Self Diagnosis checker (monitor lamp)
1F Self-Diagnosis checker (malfunction code number)
1H ignition coil leading (igt-L)
1J ignition coil trailing (Igs-T)
1L a/c relay
1N Power steering Pressure switch
1P Hazard sensor
1R Neutral Switch (M/T)
1T back up light and 5th switch (MT)
1V Trailing ignition coil (IGf-T)

2A meetering oil pump position sensor
2C Oxygen Sensor
2E Water thermosensor
2G Throttle sensor (full range)
2I Sensors Vref(+5V)
2K Intake air thermosensor (airflow meter)
2M Solenioid valve (VDI)
2O Soneloid Valve (switch)
2B Airflow meter (Vs)
2D
2F Throttle Sensor (narrow range)
2H Pressure sensor
2J Ground or open
2L Intake air thermosensor (engine)
2N Port air Solenoid Valve
2P Solenoid valve (Relief)

3A Ground
3C Ground
3E Crank angle sensor (Ne)
3G Crank angle sensor (G+)
3I Split air solenoid valve
3K Circuit opening relay
3M Solenoid valve (pressure regulator control)
3O Blower Switch
3Q Solenoid valve (bypass air control)
3S Stepping motor (MOP)
3U Stepping motor (MOP)
3W Injector (front primary)
3Y injector (rear primary)
3B Ground
3D Ground
3F
3H Crank angle sensor (G-)
3J Soneloid Valve (accelerated warm up system)
3L Headlight switch
3N EC-AT control unit
3P rear defroster switch
3R 6-port induction (6pi) system
3T Stepping motor (MOP)
3V Stepping motor (MOP)
3X injector (front secondary)
3Z injector (rear secondary)


For those who might be interested The mr2 pinout is below.
pin# US 1991 3sgte
A1 batt
A2 Diode - Electrical idle-up (ELS)
A3
A4 Stoplight switch (stp)
A5 CEL (w)
A6 Fuel Pump relay
A7
A8 ABS ECU (abs)
A9 Speed sensor (SPD)
A10 A/C clutch relay (ac1)
A11 (from ignition/clutch sw) sta
A12 Circuit opening relay (+B)
A13 Circuit opening relay (+B1)
A14 Power steering (PSCT)
A15 Power steering (PS)
A16
A17
A18
A19
A20
A21 ACT
A22

C1 Turbo Pressure sensor (VC)
C2 Airflow meter (VS)
C3 Airflow meter temp (THA1)
C4 Engine Water Temp (THW)
C5 Knock Sensor (KNK)
C6 Oxygen sensor (OX1)
C7
C8 Check connector (VF)
C9 ground (E2)
C10 EGR gas temp sensor (THG)
C11 Throttle position sensor (VTA)
C12 Cruise control/TPS (IDL)
C13 Turbo pressure sensor (PIM)
C14 Oxygen sensor (Ox2)
C15 Check Connector (T)
C16 Distributor (G-)

B1 Distributor (NE)
B2 Distributor (G2)
B3 Ignitor (IGF)
B4
B5
B6 Turbo VSV (TPC)
B7
B8 (oxygen sensor heator) HT
B9 Idle ISC valve (RSO)
B10 Cold start injector/injector time sw (STJ)
B11 injector (#2)
B12 injector (#1)
B13 Ground (E01)
B14 Ground (E1)
B15 Distributor (G1)
B16
B17 (circuit opening relay inductor) FC
B18 VSV for t-vis (TVIS)
B19
B20 Ignitor (IGT)
B21
B22 Idle ISC valve (RSC)
B23 VSV for EGR system(EGR)
B24 injector (#4)
B25 injector(#3)
B26 ground (E02)