90 Wire Disaster! Please Help!

[@TDC]

Hey guys. I was in the middle of installing Link v3 Full in my 90 1g and I believe I came across the reason it is not working connecting correctly. 2 of my ECU harnesses are mixed up like crazy. My car was working perfectly fine. I tried to hook up my Eprom with Link and I cant get a response from the ECU. I created a drawing showing how the wires are right now along with some pictures of the actual wiring. I would really appreciate if another 1990 DSM owner could post some pictures of there ECU wiring harnesses.

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As you can see that Pin #2 has no wire in it at all. Pin #2 is Diagnostics/Data Transfer Select. I ran a wire from Pin #2 on the ecu to Pin 10 on the diagnostics connector hoping this would solve my Link connecting problem but still I cannot connect. This is how it looked when I first took a look this morning. You can see the light shining through where the wire should be.

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Here are pics of the actual wiring.

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This is the wire from harness C-59 Pin #107 that has a different wire from what the pin out says should be there.

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[92AWDHX40]

Visual Frequently Answered Questions - Home Page

http://www.dsmtuners.com/forums/art...12841-1990-engine-control-wiring-harness.html


if you need more help lmk i have some harnesses available too.

 

[@TDC]

Visual Frequently Answered Questions - Home Page

http://www.dsmtuners.com/forums/art...12841-1990-engine-control-wiring-harness.html


if you need more help lmk i have some harnesses available too.

Thanks for the links! I would hate to have to switch my whole wiring harness because of this. My car runs fine just wont connect to Link. How much for a complete 90 harness???

 

[19Eclipse90]

You sure you aren't looking at the connectors wrong? That pin #2 on the 24-pin ECU connector that is missing is not pin #2 at all, it would be pin #11 which has no wire on the '90 harness as it is for ABS.

Same case could be made for the C-59 connector where the white wire is supposed to be red. It looks absolutely correct to me, compared to the 1990 Harness article Victor provided for you.

http://www.dsmtuners.com/forums/articles-tuning-ecu/246467-how-identify-ecu-pin-numbers.html

 

[92AWDHX40]

I dont have the harness i have some yellow plugs its a 92 but a lot of them are the same as a 90, ill look in my dsm box tommorow.

 

[BoostedBeaver]

19eclipse90 hit the nail on the head. You are suppose to be reading the plug as if it were plugged in.

I guess its back to the drawing board for the connection issue.

Robert

 

[@TDC]

You sure you aren't looking at the connectors wrong? That pin #2 on the 24-pin ECU connector that is missing is not pin #2 at all, it would be pin #11 which has no wire on the '90 harness as it is for ABS.

Same case could be made for the C-59 connector where the white wire is supposed to be red. It looks absolutely correct to me, compared to the 1990 Harness article Victor provided for you.

http://www.dsmtuners.com/forums/articles-tuning-ecu/246467-how-identify-ecu-pin-numbers.html

Oh my goodness! I need to call it a day! Thanks for the clarification. Since all my connections are fine that leads me to the next question. Why the hell isnt ink connecting????

19eclipse90 hit the nail on the head. You are suppose to be reading the plug as if it were plugged in.

I guess its back to the drawing board for the connection issue.

Robert

Thanks for the help sir! I'm stumped as to why Link is not finding the ECU??

Can someone please shed some light on how to test for voltage on connector plug using a multimeter??? I connect the red probe to the harness and the black to a ground and get nothing. I am using a cen tech multimeter. (Harbor Freight $3) I keep trying to find out how to use a manual ranging multimeter but I cant get a solid answer on how to correctly use it for working on my car. Thanks for the help.

 

[19Eclipse90]

I don't know near enough about Link to even begin trying to help you figure that out. But for the multimeter stuff, here's a start: http://www.dsmtuners.com/forums/newbie-forum/451488-multimeter-setting-test-pin-41-a.html

And yes, the red to the source and the black to a ground would be the way to do it: http://www.dsmtuners.com/forums/articles-electrical-wiring/404574-multi-meter-usage-primer.html

 

[@TDC]

I don't know near enough about Link to even begin trying to help you figure that out. But for the multimeter stuff, here's a start: http://www.dsmtuners.com/forums/newbie-forum/451488-multimeter-setting-test-pin-41-a.html

And yes, the red to the source and the black to a ground would be the way to do it: http://www.dsmtuners.com/forums/articles-electrical-wiring/404574-multi-meter-usage-primer.html

Thank you sir!

 

[BoostedBeaver]

I am guessing that I do not need to pull the ECU now???

Another question, have you tried using another computer??? Just borrow a buddies, download the software, and give it a shot. Better yet, if you know someone local that has a working link laptop that would be great. Give this a try and let us know how it works.

Robert

 

[@TDC]

I am guessing that I do not need to pull the ECU now???

Another question, have you tried using another computer??? Just borrow a buddies, download the software, and give it a shot. Better yet, if you know someone local that has a working link laptop that would be great. Give this a try and let us know how it works.

Robert

I'm in the works of trying this out!! I shall be back with the results!

 

[@TDC]

Also if it helps any my Mac worked perfectly fine when I had link for my 2g idk what the difference is now??

 

[Tyeler18]

You sure you have the correct drivers and com port set up? It took me about 2 hours to finally get my correct com port swapped to use my link cable.

 

[@TDC]

You sure you have the correct drivers and com port set up? It took me about 2 hours to finally get my correct com port swapped to use my link cable.

Well when I install the driver for Mac I am only allowed to download 1 driver which is the snow leopard driver! My Mac OSX will not allow me to download any other driver. I did this when I had my 2g and link worked perfectly fine.

 

[Tyeler18]

What version of link did you have in the 2g? I'd assume pre-v3? I'm not real familiar with MAC so it's hard for me to help, but it sounds like something with the cable isn't installed correctly. Can you post a picture of your opening screen and what com port ecmlink is defaulting to when you try and connect (assuming MAC works the same way that is)?

 

[@TDC]

What version of link did you have in the 2g? I'd assume pre-v3? I'm not real familiar with MAC so it's hard for me to help, but it sounds like something with the cable isn't installed correctly. Can you post a picture of your opening screen and what com port ecmlink is defaulting to when you try and connect (assuming MAC works the same way that is)?

It was v3 full and sure ill post some pics in a minute!

 

[@TDC]

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It even recognizes my EcmLink cable!

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[Tyeler18]

Definitely different that PC by a long shot, but that was the same message I was getting when my COM port was wrong. I can't help much more than that because of my limited MAC knowledge, but to me it seems to either be a cable issue or a serial issue. The v3 cables do go bad from time to time, I ended up sending mine in because it went bad and would give a similiar message. They will replace them for free though.

 

[@TDC]

Definitely different that PC by a long shot, but that was the same message I was getting when my COM port was wrong. I can't help much more than that because of my limited MAC knowledge, but to me it seems to either be a cable issue or a serial issue. The v3 cables do go bad from time to time, I ended up sending mine in because it went bad and would give a similiar message. They will replace them for free though.

Thanks for all the help! I really appreciate it. I would just love to get this over with and move on!! I am in the process of finding another computer to try to connect with. Hopefully it will connect so that I'll know its something on my computers end!!

Well guys! I tested my diagnostic connector for the continuity with the ECU pins. I am 100% sure that this time I used the correct pins. I tested the following pins for continuity. First was diagnostic connector pin #1 to ECU pin #1 I placed multimeter probes to both pins and got a reading. So basically there was no broken connection between the 2 pins. Next was pin #10 on the diagnostic connector to pin #2 on the ECU. I placed multimeter probes on both pins and got a reading. So there were no broken points in the connection between the 2 pins. Last I tested diagnostic connector pin #12 for connectivity to chassis ground and it tested fine. I then tested the voltage for pin #10 of the diagnostic connector and I got 3.37 DCV. ECMTuning says it should be 3.5v for a 1990 DSM. When I tested pin #1 for voltage I got 0.04. ECMTuning says it should be pulsing but I dont have a CEL. Does this seem like the connection between my diagnostic connector and ECU are fine???

 

[dsm-junkie]

Interested to see what the cause is.

 

[EisHERE]

Seeing this makes me want to steer clear of link.....

 

[19Eclipse90]

When I tested pin #1 for voltage I got 0.04. ECMTuning says it should be pulsing but I dont have a CEL.

This is the only part that is slightly suspect if you measured it with the ignition switch in the "ON" position. Otherwise (i.e., if this was done with ignition switch in "OFF"), everything looks fine.

 

[@TDC]

This is the only part that is slightly suspect if you measured it with the ignition switch in the "ON" position. Otherwise (i.e., if this was done with ignition switch in "OFF"), everything looks fine.

I tested this with the ignition switch in the on position. I thought that pin #1 was only for code reading purposes? If I didn't have a CEL then what should it read??

 

[@TDC]

Seeing this makes me want to steer clear of link.....

This is only a connection issue.. After I get this fixed it will be more than worth it!!

 

[19Eclipse90]

If there are no codes, there should be small fluctuations in voltage (repetitive short pulses). If it remains constant -- and I find it improbable considering you've said the car runs fine otherwise -- that is indicative of an ECU problem: ECU Code Checking.