ECM wiring diagram

1991 BUICK PARK AVENUE
160,000 MILES • 3.8L • V6 • 2WD • AUTOMATIC
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FRAGO
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I'm looking for a wiring diagram of the three connectors related to the ECM. The former owner of my car has made some modifications on the pink and black lead and I would like to know what he has done?
Thanks for helping.
Franck
Sep 27, 2020 at 6:20 PM
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ASEMASTER6371
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Good morning,

I attached the wiring diagram of the ECM as you requested.

Let me know if you need any other help.

Roy
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Sep 27, 2020 at 6:47 PM
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FRAGO
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Yes, I said thanks and said that I will investigate and give you feedback...
Sep 27, 2020 at 7:06 PM
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ASEMASTER6371
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You are welcome.

always glad to help.

Roy
Sep 27, 2020 at 7:12 PM
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FRAGO
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Yes, I did but same problem again with the message system.. So I did investigations but the wiring diagram does not match with my ECM... The faulty pink and black is number a2 on the black 24 pins connector... What did you think about that?
Franck
Sep 28, 2020 at 4:28 AM
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FRAGO
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See the attachment....
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Sep 28, 2020 at 4:30 AM
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ASEMASTER6371
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Okay, in the diagrams I sent the pink/black is a power feed to the ECM.

Is that what this wires does?

Roy
Sep 28, 2020 at 5:26 AM
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FRAGO
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Hi Roy.

I assume that what is important is the pin number and not the color, right? The diagram leads color does not match with my connector... On my ECM, the connectors are black and green not orange...
I have to do more investigations to really conclude about the function of this pink and black lead....
Have a good day.
Franck
Sep 28, 2020 at 4:53 PM
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ASEMASTER6371
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Can I have the VIN number from the car please?

Roy
Sep 28, 2020 at 6:04 PM
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FRAGO
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Hi Roy,

VIN is: 1G4CW53LOM1702281.
I did more investigations and found out that the wiring of my car corresponds to a model 1993!
Maybe because it was sold in Europe (I'm French).
In this case the pink and black lead must be from/to the MAF?
What do you think about that?
The strangest thing is that the red replacement lead goes to a harness like if it was from the manufacture.
Is it a spare lead in case of...?
Sep 29, 2020 at 2:19 AM
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ASEMASTER6371
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The VIN comes back the car I gave you for the diagrams.

What does not function that makes you want to replace this?

Where is the other end of the wire?

Roy
Sep 29, 2020 at 5:39 AM
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FRAGO
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Hi Roy,

I bought this car that has not run for a while. I had to remove the dashboard to fix the HVAC and I discovered that tricky modified pink and black lead... Somebody has cut and strapped it with a red lead that goes I don't know where yet... Before putting back the dashboard, I just wanted to be sure about the purpose of this red lead...
I think that I have everything to finish this investigation... I will give you feedback if you want.
Thanks again for helping, I really appreciate your patience.
Merci et bonne journée,
Franck
Sep 29, 2020 at 5:54 PM
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ASEMASTER6371
  • ✓Experienced Mechanic
  • 52,796 POSTS
You are welcome.

Always glad to help.

Roy
Sep 29, 2020 at 6:04 PM
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