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Below is the pinout for a 92 Subaru SVX Engine Control Unit (ECU).

enter image description here

Since the wiring harness is no longer collocated with original car, I have no idea as to what the pinout for the Data Link Connector (DLC) might be. Can anyone help me align the pinout guide to exactly where it is attached to the DLC? I'm assuming it comes from the "C" connector (top center with 16 pins), where the greyed out wires are at, but even so, I don't know how they align to the connector itself. I could guess and fumble through it, I guess, but I think this might risk damaging the ECU or my code reader. I don't want either to happen.

UPDATE NOTE: To clarify what's going on ... I am installing an EG33 (3.3L H6) engine into a 96 Impreza. The EG33 is from a 92 SVX. To do this, I have to take out most of the wiring harness which runs the EJ22 (2.2L H4) engine which comes standard in the 96 Impreza and install the engine side wiring harness and ECU from the SVX into the Impreza. The Impreza ECU remains in the car to run the gauges and other things, while the SVX ECU runs the engine and related components. The two are married together to provide everything which is needed to run the car. I need to understand the connection of the SVX ECU to the DLC so I can attach my OBDI code reader to it and get any diagnostics back from the ECU it can provide. This will hopefully help me solve the problem I'm having right now with it not wanting to start.

  • I do not understand the question but will add this comment: The OBD11 DLC connector is defined in the SAE J1962 specification and should not change across vehicles. – Fred Wilson Nov 21 '16 at 23:10
  • @FredWilson - Yes, this is for OBDI, so wouldn't be the same. I can figure out which pins of the DLC itself are for the data ... I just don't know which ones from the ECU connect to these pins. Just need a little help, lol. – Pᴀᴜʟsᴛᴇʀ2 Nov 21 '16 at 23:15
  • 1
    what year did the ecu come out of? – Ben Nov 22 '16 at 0:25
  • @Ben ... Adding info. – Pᴀᴜʟsᴛᴇʀ2 Nov 22 '16 at 1:30
  • So to clarify: You're putting an EG33 engine and a '92 SVX ECU into a '96 Impreza body? You're sure that the ECU is literally from an SVX (not an Impreza)? Previously, you were looking at wiring diagrams for a '96 Impreza ECU. (I assume you know this, but the EG33 only ever came in the SVX.) Did the ECU come from a North American SVX (or non-Japanese)? Not trying to doubt you, just clarify some things for those less well-versed (like me!). – Zach Mierzejewski Nov 22 '16 at 4:46
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Look at the MPFI B61 connector and Select Monitor connector, pin 2 on the SM connector will be brown/white (pin 1 is blank) and pin 9 will be black/red. On the MPFI B61 connector pin 1 is white and pin 16 is yellow.

Note that the Data Link Connector is called the Select Monitor Connector.

MPFI Connectors enter image description here

Wiring Diagrams

enter image description here enter image description here

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I found the 1992 Subaru SVX Wiring Diagram and Troubleshooting manual.

In the contents, there is 15. ENGINE ELECTRICAL (MPFI) SYSTEM .... 44. The page numbers of the contents and the PDF don't line up.


On page 42 of the PDF (but labeled 43 in the text of the PDF), aka page [0415] 6-3, you'll find this diagram:

Wiring Diagram.

None of them are labeled Data Link Connector, but I'm pretty sure we're in the right area.


From this image, Fig 6., on page 77 of the PDF (but labeled 11), aka page [0500] 6-3:

Lower left footwell graphic.

We can rule out the B37 Diagnosis Terminal and the B36 Diagnosis Connector.


On page 82 of the PDF (but called 91 in the PDF), aka page [0604] 6-3, you'll see these three images, Fig. 69:

Lower left footwell connectors graphic.

These are all the connectors in the lower left footwell.

Connectors 33-37 names. Connector 58 name.

We ruled out B36 and B37 already. We'll rule out B58 because that is for the air bags. We'll rule out B33 because it is for setting the temperature units.

That leaves us with either B34 or B35.


You say that there are supposed to be 12 pins on that generation of Subarus' DLC. (OBD1 is a misnomer because there was never an officially recognized OBD1 standard and Subaru definitely wasn't following the non-existant standard in '92.)

From the previously listeds image we can see that:

  • B34 has 9 pins, but only uses 3 to connect to the ECU.
  • B35 has 20 pins, but only uses 5 to connect to the ECU.

Back up on page 42, we can see the pinouts:

B34 connector pinout. B35 connector pinout.

And, on page 2, we see the description of how to read the pinout diagrams, Fig. 2:

How to read pinout diagram.


On page 4, aka page [0102] 6-3, we see the Color Code diagram:

enter image description here


Back up in the first image we see that:

B34Uses:

  • Pin 13 (Light Green/Red) connected to B61 Pin 7
  • Pin 14 (Brown/White) connected to B61 Pin 8
  • Pin 17 (Orange) connected to B61 Pin 13

B35 Uses:

  • Pin 9 (Black/Red) connected to (A)
  • Pin 8 (Blue/Yellow) connected to B61 Pin 15
  • Pin 3 (Light Green/Red) connected to B61 Pin 7
  • Pin 2 (Brown/White) connected to B61 Pin 8
  • Pin 5 (Brown/Red) connected to FB-42 Fuse No. 18
  • While this probably gets me which pins connect, how do these align with the DLC? – Pᴀᴜʟsᴛᴇʀ2 Nov 22 '16 at 11:29
  • @Pᴀᴜʟsᴛᴇʀ2 After reading that document more, I don't think that B36 is what you need. I think you want B34. How many pins are on your code reader for that generation of Subaru's? I ask because I want to independently verify that number lines up with the number of pins on B34. – Zach Mierzejewski Nov 22 '16 at 13:07
  • I believe there are usually only two on an OBDI DLC (could be three), even though there are 12 (IIRC) pins which show in the DLC. I'm only going to use jumper wires with alligator clips to connect them anyway. – Pᴀᴜʟsᴛᴇʀ2 Nov 22 '16 at 13:43

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