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Jerry Newton
Jerry Newton, Chevy Technician
Category: Chevy
Satisfied Customers: 4508
Experience:  ASE Master Technician, L1, Master GM Technician. Over 20 years of bumper to bumper GM experience.
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I changed a 93 k3500 diesel with 4l80 trans to gas engine

Customer Question

hi I'm Jerry I changed a 93 k3500 diesel with 4l80 trans to gas engine 5.7 using the 4l80 tran. I need to know what has to be changed on wiring through firewall for transmission to work
Submitted: 1 year ago.
Category: Chevy
Expert:  Jerry Newton replied 1 year ago.

Start with trouble codes, the ECM might be telling you what's wrong with those circuits. Can you get a scan tool that connects to this truck, or flash out the codes to see what's stored in the ECM?

Customer: replied 1 year ago.
Trouble codes 42,54,66,67 . I cleared codes and code 66 was the only one that erased. Current codes 66 ,67 and 66 erased
Expert:  Jerry Newton replied 1 year ago.

The wiring is not correct, or it's damaged. I am attaching a schematic that shows what each of the transmission wires goes to, you'll have to test every one and make sure the correct wires are in the correct pins. You'll also need to make sure that you have power on the appropriate pin, none of the solenoids will work if you don't have power on pin K.

Customer: replied 1 year ago.
The service number on my pcm is16196395 that is what i wired to. My transmission has 11 pins in it 2 speed sensor
Expert:  Jerry Newton replied 1 year ago.

My diagram shows 12 wires going to the trans. Which of those 12 do you not have?

Customer: replied 1 year ago.
I have only 1 power wire instead 2 on my transmission pin. i have 3 rows 0f pins top row has 4 pins, middle row has 1 pin which is power to solnoid inside transmission, bottom row has 6 pins, very bottom row is empty
Expert:  Jerry Newton replied 1 year ago.

http://www.michaelrenz.com/4l80e/Images/93_94%20S10%204l60E%20connector%20pinout.jpg

Look at that image for reference of the pin numbers, check the diagram and make sure the correct wires are in the correct pin slots.

Customer: replied 1 year ago.
I rewired my pcm to the diagram that I received from you. engine did not start, rewired back engine started. transmission diagram that was just sent is what my 4l80 has
Expert:  Jerry Newton replied 1 year ago.

There is something definitely amiss about that, because there's nothing in the transmission wiring that should stop the engine from starting. You have to have some incorrect wires on those circuits, or in the wrong pins at the ECM, or something along those lines.

Customer: replied 1 year ago.
the transmission wires that I received from you was half control were in red connector and the others on blue connector, the one I have was mostly in blue connector
Expert:  Jerry Newton replied 1 year ago.

What connector are you talking about? What's red and blue?

Customer: replied 1 year ago.
The plugs that go into the pcm are red and blue
Expert:  Jerry Newton replied 1 year ago.

I see, I didn't get what you meant, I was thinking of the trans connector.

In the diagram that I sent, only two wires go to the C/D connector, the rest of them go to the A/B connector. Where do you see that half of them go to each connector?

Customer: replied 1 year ago.
From the wire diagram that you sent me on the pcm . Half went into one plug and half goes into the other plug
Expert:  Jerry Newton replied 1 year ago.

Not the way I'm looking at it. Pins G and H go into one connector, the rest of the wires go into the other connector. I'm looking at the schematic that I sent you to arrive at this.

Customer: replied 1 year ago.
Can u send me the one your looking at (schematic)
Expert:  Jerry Newton replied 1 year ago.

It's the same one that's attached above, I'll attach it again.

Customer: replied 1 year ago.
Im going out to check the wire's on the truck one more time
Expert:  Jerry Newton replied 1 year ago.

OK. It sounds like you have a number of them misrouted.

Customer: replied 1 year ago.
when I moved all the wires on my pcm to diagram. I have 8 wires for engine side not plug in. would you have diagram the for engine side also or complete pcm diagram Thank You for your help. Will let you know what happens tomorrow.
Expert:  Jerry Newton replied 1 year ago.

The diagrams from 1993 are really, really tough. They originally came to dealers on giant foldouts, like blueprints. Those are long gone, they were stupid anyway and were difficult to read, and now that we have switched to electronic format, all we have are pictures of portions of the overall diagram.

I am attaching a schematic for a 1995, and it should be substantially the same, if not exactly the same, as your 93. By 95 they were switching to electronic formats, so the diagrams are easier to read. This should give you what you need to find where these wires go.