8 Valve ECU's  only:                                                           

Here is the ECU out of my 1991 Tracker with 4wd and M/T , not too fancy looking.
Typical of all 91's to 95 , and 8 valves ONLY.  All 8v ECU need the Rubicon Caps, replaced just  once, per car /ECU life time. 

Drawing #1 (8v typical)

Located behind Left FRONT Radio speaker. remove speaker and look.  (all kicks, 89-95)
All ECU's (PCM's) have the 33920 prefix, if not , its not an ECU, but RWAL or a TCM, or  ABS module.
The The 56B = 8valves, the 40 is for A/T tranny the  last digit can vary due to revision levels or smog compliances rules.
The US means USA, and AT means Automatic Ttransmision. the other codes are all secret Mitsubishi numbers.

The next picture is of the guts, the main circuit board.
It is just a simple microprocessor with some RAM and some ROM.

I cured mine by replacing all the black and aluminum CAPS, repairing the grounds and by putting heat sink compound on the power transistors.
C101,103,105,111 were replaced with Premium 105 DEGREE CENTIGRADE caps, made in Japan , not China !

I marked the transistors,below, that drive the TBI injector, so you can find them and replace them.

You can try to repair the unit or buy (trade) ECU's  on EBAY, Search "SideKick ECU" bingo.  $70 exchanged.< a great GUY!

You can buy a new one from Suzuki for $1400 ( will that be VISA or Mastercard ?   No way Jose' ). Never pay more than $200 !
See my new  parts list for the critical components shown, below:
We have done this 100's of times on the  forums, now, and 99% success rate.  Even DIY works  most times.

This information below , is available, no where else.  Enjoy: !
8 valve engines only:
USA/Canada typical:  91-95 ( but 89/90 are similar)

The 8v TBI Schematic  1991-95 (only wires ,to make engine run perfect !)

1989/90  8V ?(it's quite different )

My INJECTOR Schematics and Transistor OUTPUT function ID page , you can repair bad outputs !

The Full PDF of the below is here, plus real photos of connectors.

1991-95, FSM Pin-Out  pages.  Look at the pins , functions and normal voltages.

As you can see,some pins will be empty
A4 ,   only Calif. cars have A4 pins wired to ground,
A2 is A/C , no factory Air, no wire here.
A16 is Calif EGR
same with the 3 transmission,  The M/T will not have TCC lockup. nor A/T start logic or A/T park /drive switch logic pins. !
M/T = Manual transmission.
Where is Pin A1 or B1? , gee, look below, at the drawing #1 , see the markings?  Bingo !

The high power feeds are on the Green and lower power sensors on the white, note gold pins on white conn.
I have all output transistors Identified.
Fully protected , Inputs usually do not blow out, just outputs .Never hot wire any ECU,  if you do, you will blow it, out, I promise ! Then I get to fix it. (grin)

Bad power to ECU:   My comments are using Suzuki pin letters,  "Bn" Pins are Green, "A" are white(old yellow)
I keep replacing  my ECU and it still does not act right.  ECU keeps resetting or wont show code 12 ,etc.
The ECU has 3 fuses , all 3 need to be good.  IG-coil, FI and Dome (memory)
When you turn the key, the Main relay must energize, if it does not, the ECU lost its ground or someone hot wired the fuel pump and burned up the B15 Diode D102 inside the ECU.
Key on and Green pin B1 and B7 most go to 12vdc or the MAIN is dead.
Green pin B15 must be about 0.7vdc or the diode inside is blown up.
All grounds cables to the engine and body to battery and body to engine must be good, clean them and grease them with silicon grease.
The critical ground must  be good.
The below tests should be done with the negative voltmeter lead connected to the MINUS  - terminal of the battery. (or to body clean shinny metal, 2nd choice)
The voltage spec. for ground   should be below 0.5v or ideally way less.  (ECU GREEN B2,B10 and A24)
  (A4 for California car only and is ground but does not power the ECU at all)
The power pins will read 12vdc, B1, B7. (green) if not , the Main relay is dead.
The B15 pin must be near 0.7vdc Ideal.  Never 12v , never 6vdc , it must be near 0v. but will never reach there fully.  (this is called forward diode drop voltage to a tech, or engineer)

The body/battery minus ground strap behind the battery is very critical. It must be good, so starting current does not pass through the ECU.  VITAL !
Make sure the battery main large black (biggest) minus cable goes to the starter and is clean and tight on both ends,
if not, you risk sending starter currents through the ECU. This would be very bad.

The schematic pages show all the other ECU power pins. The power to the ECU must be good and so must the main power feed in the body of car, fuse box 1 and 2.

Typical of all 91's to 95 , and 8 valves ONLY.
Drawing 2:  -56B30 ECU.

C111 is the main failure item,  about a 100% failure rate after 10years. Costs 33 cents to replace it.

I need a new injector driver for my 8valve ECU above:
If you have spark and no DTC 41 or 42 cranking, then these 2 are bad (D1415 is first to go)

Q101 is 
2SB1020   PNP  (Plus  driver)      Date Sheet for B1020

Q102  is the 2SD1415 NPN (Ground side driver)    Data sheet D1415

Source 1:   "MCM" carries the 2SD1415 but not the  B1020. (they ship 1 part in many  cases, and do so, lightning fast "automated processing")

Source 2: "Match a Knob in NY" , has both transistors for the injectors. , min. order is 2 , and $20 miniumum order.

Source 3: "Electronx.com" has the other B1020  transistsor

eBAY HAS MANY , A B1020 search example. ( no miniumum orders, it's what you see is what you get)

More Circuit drawings and facts.
+5vdc refr. and main 5vdc power supply details.(my 8 valve reverse eng. drawing)

See photo of  Hybrid module.

See here for transistor testing.

Parts Substitutions.

If the ceramic hybrid models are bad,  I think it's the end of the road.
 ( Mitsubishi don't return calls) The big shops canabalize old dead ECU's to fix the sick.
More  8v ECU's   photos;
The 1989/90 see large DIP package MicroProcessor?  This is a 60A ECU.
I have no  reverse engineering data on this below ECU,  I has no spark generation, but does monitor spark to cut fuel at spark loss.
The pinout on this  next ECU is Unique.

Here is the 1989 ECU notice how the minus bands on CAP.'s, are not all in the same direction nor at all like the 91+ ECU's

PN: -60A32/42  MT/AT below.  ( No spark generation, that means it don't do advance ,nor does it drive the ignitor at all)
Also know as, the Gold Box ECU,  and has many -60Axx suffix partnumbers that last digit changes by smog regions or revision levels.

The later Sammuri ECU 1995?   the -80Cxx ECU. below.  

Fancy Aluminum case here.
Here is an other: Vitara Australian  ECU. 57B30 .  very diff. design and far better than any USA , of this era.

ver 3 (2007 version 1,  , revised 2-3-2013  revised for , why are pins missing,  answer, because you don't have that option !