Lm7 in 2003 Silverado
06-09-2021 | 08:49 PM
#1
Thread Starter
Teching In
Joined: Jun 2021
Posts: 7
Likes: 4
Lm7 in 2003 Silverado So I have a 2003 Silverado single cab with a 4.3 and manual trans
I purchased a running and driving 2000 Silverado with a 5.3 I cammed it had pcm tuned long tube and couple other misc. things drove the truck for about a month to ensure all working properly
Performed the swap to install the 5.3 into my single cab the truck has sentimental value to me which is why I am swapping it
swap everything over harness pcm motor 4l60 everything is bolted up plugged in. When I turn the key one click the starter engages and turns over by it self
I have read forums and forums about this will not work and I have to go to a Dbw setup and I understand that, but there has been a couple I read where you could use a 2003-2005 express van harness and pcm or have the v6 pcm flashed to a v8 and it should work
I would prefer for everything to work they way it was suppose to like factory so if I did a stand alone it wouldn’t work that way
Maybe another option might be to just swap all electrical from the donor truck to the 2003
I’ve lost countless hours of sleep trying to figure out which route to go and a direction
and help would be much appreciated
I purchased a running and driving 2000 Silverado with a 5.3 I cammed it had pcm tuned long tube and couple other misc. things drove the truck for about a month to ensure all working properly
Performed the swap to install the 5.3 into my single cab the truck has sentimental value to me which is why I am swapping it
swap everything over harness pcm motor 4l60 everything is bolted up plugged in. When I turn the key one click the starter engages and turns over by it self
I have read forums and forums about this will not work and I have to go to a Dbw setup and I understand that, but there has been a couple I read where you could use a 2003-2005 express van harness and pcm or have the v6 pcm flashed to a v8 and it should work
I would prefer for everything to work they way it was suppose to like factory so if I did a stand alone it wouldn’t work that way
Maybe another option might be to just swap all electrical from the donor truck to the 2003
I’ve lost countless hours of sleep trying to figure out which route to go and a direction
and help would be much appreciated
06-11-2021 | 09:50 PM
#2
TECH Enthusiast
Joined: Mar 2005
Posts: 665
Likes: 380
From: South Carolina
You have three options as the truck 99-02 harness and the 03+ harnesses are different :
Change the pinouts so the 2000 harness will work in the newer 2003 truck.
Swap to a Express or Savanna van harness and use the existing V6 cable throttle pedal.
Swap to an 03+ truck, tahoe, yukon or escalade harness to support a DBW throttle body, TAC module and DBW accelerator pedal.
Be aware in the V6 trucks with the cable pedal there is a large metal plate under the column that interferes with mounting a DBW pedal. Most just shoot the pedal mounting bolts through that plate. You'll need self tapping bolts or drill and use non self tapping metal bolts.
Change the pinouts so the 2000 harness will work in the newer 2003 truck.
Swap to a Express or Savanna van harness and use the existing V6 cable throttle pedal.
Swap to an 03+ truck, tahoe, yukon or escalade harness to support a DBW throttle body, TAC module and DBW accelerator pedal.
Be aware in the V6 trucks with the cable pedal there is a large metal plate under the column that interferes with mounting a DBW pedal. Most just shoot the pedal mounting bolts through that plate. You'll need self tapping bolts or drill and use non self tapping metal bolts.