4.3 to 5.3 Ls swap
Thread Starter
Teching In
Joined: Apr 2020
Posts: 13
Likes: 3
From: PHX
4.3 to 5.3 Ls swap Hello everyone new to the forum... recently picked up an 03 4.3 Silverado for a very good deal and want to swap it. I picked up an 01 Tahoe today 5.3 2wd 4l60e drove it an hour home and it’s the perfect candidate for the swap. One thing I’m reading on is something about the computers. Yes they are both DBC and I know it would be an easy swap only thing I’m worried about is will all my gauges work fine and what not? People are saying online if you’re swapping a 99-02 get a V8 those years. Swapping an 03-06 get a V8 those years. Why exactly is this? I picked the 01 because of the DBC set up. Much easier to do and play with. Thanks
Thread Starter
Teching In
Joined: Apr 2020
Posts: 13
Likes: 3
From: PHX
from my understanding PO1 is an 03 computer P59 started in 04. And I’m going to be using the computer from the 01 motor in the 03 truck. Will it work with the truck harness itself on the inside of the truck is my question? If not what modifications are required?
The basic long block is the same.
The 99-02 use a single wire Oil Pressure switch 03-07 classic use a 3 wire setup. The O2 sensor plugs change as well.
The P01 and P59 use Class 2 data bus Not CAN.
The they are not interchangeable. P01 is a 512KB operating system. The P59 Is a 1 MB Operating system.
The 99-02 use a single wire Oil Pressure switch 03-07 classic use a 3 wire setup. The O2 sensor plugs change as well.
The P01 and P59 use Class 2 data bus Not CAN.
The they are not interchangeable. P01 is a 512KB operating system. The P59 Is a 1 MB Operating system.
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Joined: Mar 2020
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I've got a 2002 P01 411 PCM working a 2010 5.3 with DBC in a '99 s10. Didn't have a single problem with the gauges, everything works.
I did a VVT delete and 24x conversion. The only issue is where to put the knock sensors since the GEN 4 block doesn't have them in the valley. So the old style need to be screwed into a spare hole in the block and hope it works.
And on another truck, a 2001 s10 I swapped in a 2003 4.3 with a P59 PCM. You'd never know it was swapped. I dropped it in, plugged it in, ran it.
I did a VVT delete and 24x conversion. The only issue is where to put the knock sensors since the GEN 4 block doesn't have them in the valley. So the old style need to be screwed into a spare hole in the block and hope it works.
And on another truck, a 2001 s10 I swapped in a 2003 4.3 with a P59 PCM. You'd never know it was swapped. I dropped it in, plugged it in, ran it.
Teching In
Joined: Jun 2020
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Need help Hi! I’m angel, I’ve started on a build and am in much dire need for some help to get it finished!
I recently got a 02 v6 Silverado ext cab and had a 04 5.3 I dropped in to replace the blown 4.3 in it. I went and pulled the wiring harness for the 04 v8 along with flashing and removing vats and tuning the ecm for the v8 everything is plugged in. New power wires and grounds are in place and even replaced neutral safety switch and such small other things as like shift cabe for the trans. Have the pedal and all for the drive by wire set up and at this point we’ve got the battery and all hooked up and get nothing except signal to the reverse lights, radio and running lights. No dash lights, no headlight switch signal. Need as much help as I can get !! Please!
I recently got a 02 v6 Silverado ext cab and had a 04 5.3 I dropped in to replace the blown 4.3 in it. I went and pulled the wiring harness for the 04 v8 along with flashing and removing vats and tuning the ecm for the v8 everything is plugged in. New power wires and grounds are in place and even replaced neutral safety switch and such small other things as like shift cabe for the trans. Have the pedal and all for the drive by wire set up and at this point we’ve got the battery and all hooked up and get nothing except signal to the reverse lights, radio and running lights. No dash lights, no headlight switch signal. Need as much help as I can get !! Please!
