4L80e 1987 C 10 ls swap not shifting

[bkhrla]

Hey guys I need some help. I got a
6.0 with a 4l80e
Btr stage 2 cam
799 heads
Short headers
Ls7 lifters
Swap the trans to a 1987 Chevy c10 from 2002 Chevy Silverado 2500

I finally got it “running” I’m able to drive it but my transmission isn’t shifting.
When I drive It does high revs the rpm gauge goes high and no sign of shifting

 

[bkhrla]

Another picture

 

[NickTransmissions]

Hey guys I need some help. I got a
6.0 with a 4l80e
Btr stage 2 cam
799 heads
Short headers
Ls7 lifters
Swap the trans to a 1987 Chevy c10 from 2002 Chevy Silverado 2500

I finally got it “running” I’m able to drive it but my transmission isn’t shifting.
When I drive It does high revs the rpm gauge goes high and no sign of shifting

Sounds like either it's in limp mode or no vss data is being received...What's the deal with the transmission? Is it a fresh rebuild or used? What are you using to control the transmission?

 

[bkhrla]

I’m using a stand alone harness, I’m using the transmission from my other truck which was running fine before I did the swap.

 

[bkhrla]

Sounds like either it's in limp mode or no vss data is being received...What's the deal with the transmission? Is it a fresh rebuild or used? What are you using to control the transmission?

Sorry I’m new here. I’m using a stand alone harness, I’m using the transmission from my other truck which was running fine before I did the swap. There’s no oil burning, or any burning smells. My oil level is good. Btw I did replace the ISS sensor but that didn’t change anything.

 

[NickTransmissions]

Sorry I’m new here. I’m using a stand alone harness, I’m using the transmission from my other truck which was running fine before I did the swap. There’s no oil burning, or any burning smells. My oil level is good. Btw I did replace the ISS sensor but that didn’t change anything.

Is the transmission stuck in first gear or 2nd gear?

 

[bkhrla]

Is the transmission stuck in first gear or 2nd gear?

I’m not sure, it drives but as soon as it takes off it goes into high revs and my ROM gauge increases but no decrease.

 

[bkhrla]

RPM gauge

 

[NickTransmissions]

I’m not sure, it drives but as soon as it takes off it goes into high revs and my ROM gauge increases but no decrease.

What is the "stand alone harness" connected to?

Unplug the large connector on the driver's side of the transmission, get in, fire it up and put it in Drive. If it feels different then you're in second gear when plugged in which means limp mode. If it feels different (i.e like its in a deeper gear), you're in first gear and have an comm issue between the vss and pcm.

 

[bkhrla]

What is the "stand alone harness" connected to?

Unplug the large connector on the driver's side of the transmission, get in, fire it up and put it in Drive. If it feels different then you're in second gear when plugged in which means limp mode. If it feels different (i.e like its in a deeper gear), you're in first gear and have an comm issue between the vss and pcm.

My harness is connected to the ECU and ecu to my transmission

 

[bkhrla]

What is the "stand alone harness" connected to?

Unplug the large connector on the driver's side of the transmission, get in, fire it up and put it in Drive. If it feels different then you're in second gear when plugged in which means limp mode. If it feels different (i.e like it’s in a deeper gear), you're in first gear and have an comm issue between the vss and pcm.

I also want to mention, when I fire it up and I shift into reverse or drive I do feel the shifts.

 

[NickTransmissions]

My harness is connected to the ECU and ecu to my transmission

You need to determine if you have a vss problem or whether you're in limp mode due to a failed/shorted solenoid or short/problem somewhere upstream of the transmission. So follow the procedure i specified above and let me know if the trans feels like it's in the same gear as when it's plugged in or a different gear. Also scan the pcm for codes to see if any DTCs have been set/stored. Let me know what you find...

 

[bkhrla]

You need to determine if you have a vss problem or whether you're in limp mode due to a failed/shorted solenoid or short/problem somewhere upstream of the transmission. So follow the procedure i specified above and let me know if the trans feels like it's in the same gear as when it's plugged in or a different gear. Also scan the pcm for codes to see if any DTCs have been set/stored. Let me know what you find...

I did what you specified. I didn’t feel any difference.

 

[bkhrla]

I did what you specified. I didn’t feel any difference.

I also ran a continuity test and there were no errors or issues.

 

[bkhrla]

I also ran a continuity test and there were no errors or issues.

Only codes I have are a misfire and knock sensors