Check engine light but no computer?

OVERLORDOFMARS

MEMBER
1986 CHEVROLET TRUCK
6 CYL
2WD
MANUAL
212,900 MILES

Hello, I have a 1986 Chevy 2500 with the 4.8 L Inline six engine. The check engine light came on but I cannont find the reason. The truck began to idle bad about a week after the light. Here is my problem, there is no code test jack that I can see. I have looked every where under both sides of the dash. I cannot find the typical computer either! What is making this light go on and where is this hidden ECM and test jack?

4 Replies

MERLIN2021

MECHANIC
17,250 POSTS

Here is the location for the engine control unit and PCM. Check out the images (Below). Please let us know how it goes

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Saturday, August 16th, 2008 AT 8:16 PM

OVERLORDOFMARS

MEMBER
2 POSTS

I took the glove box out, there is nothing up there but a speaker for the radio.

What is this check engine light connected to?

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Saturday, August 16th, 2008 AT 8:23 PM

MERLIN2021

MECHANIC
17,250 POSTS

E had them under one of the seats, but this is c20, forget about what engine you think the diagram shows, that was not even a consideration fo the part. And if you look close, thats a carb on top!

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Saturday, August 16th, 2008 AT 8:29 PM

DON SAMSONITE

MEMBER
1 POST

I had to replace mine as well but let me tell you that you will have to get it reprogramed for your truck I know because I had the same issue hopefully this helps you as well

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Monday, July 17th, 2023 AT 7:05 PM