Ls swap and 4l60e won't shift

[ericcamaro]

I swapped in a 5.3 and 4l60e out of a 2004 Buick Ranier (Trailblazer) into my 81 K5 Blazer. The trans and engine worked great in the donor car without any issues. Everything in the swap went pretty smooth but I cannot get the transmission to shift when it is in Drive. I have reverse, and forward but it feels like it is stuck in 2nd (could be 1st) gear. I have been able to get it to a higher gear by manually shifting it. I am running a 8k speed sensor off the speedo cable and the PCM was tuned for it. Any help would be great. I have a code scanner and have run codes from the PCM and there is only emissions sensor codes from things I have not hooked up yet.

 

[Bent77]

My initial thought is the ECM doesnt like the signal the 8k is delivering

 

[sweetk30]

sounds like limp more and thats 2nd gear .

also how did they set it up for park/n/reverse gear selector switch .

 

[ericcamaro]

My initial thought is the ECM doesnt like the signal the 8k is delivering

I am thinking this might be the issue as well but it seems to be a common part used by many for this swap without issue. I am going to try and get a scan tool that can stream live data to show me if the computer is reading the correct speed from the VSS.

 

[ericcamaro]

sounds like limp more and thats 2nd gear .

also how did they set it up for park/n/reverse gear selector switch .

I am using the stock column shifter attached to the gear selector on the side of the trans. The computer has a Park Nuetral switch and it is still using the factory K5 switch on the steering column as well. Both seem to be operating correctly.

 

[Blue85]

With all shift solenoids dead you only have R and 2. Are you sure there is power to the tranny and a good ground? If you don't have connection to the solenoids, the PCM will set a code for high resistance. Is this all wiring from the donor vehicle? 4L60-E and 4L80-E use the same connector, but with different pinouts.

 

[ericcamaro]

With all shift solenoids dead you only have R and 2. Are you sure there is power to the tranny and a good ground? If you don't have connection to the solenoids, the PCM will set a code for high resistance. Is this all wiring from the donor vehicle? 4L60-E and 4L80-E use the same connector, but with different pinouts.

I will have to double check the power on the transmission connector tomorrow, I sure hope that it is that easy. I pulled the engine and trans together from the donor vehicle and never even removed the wiring harness, so I know that is not the issue. I would think if the Trans was not getting power I would have some kind of trouble code in the PCM but I am getting nothing transmission related.

 

[ericcamaro]

I confirmed that the trans is getting power and shifting through multiple gears manually. I pulled the fuse to the trans and it went into limp mode and threw a bunch of codes. This leads me to believe that the issue must be with the speed signal from the sensor.
I confirmed the vss is good and getting signal to the pcm. Does this mean the pcm was not programmed correctly and it does not think it's going fast enough to shift? How can I confirm this?

 

[Greg Ducato]

The 4L60E uses 40 pulse per driveshaft revolution speed signal, check to be sure you are programmed for that

 

[onelowsonoma2]

i am having same issue, just did a full swap 5.3 4l60e all worked well in the doner truck, now stand alone harness, computer has been flashed for 8k, pass through code generator, and wont shift, , no codes besides i keep getting a maf sensor code, i do get a reading though my scan tool for the vss, 2nd and reverse, i can pull it down manually to first and manually shift to second, i have checked for power all is fine, any help would be great

 

[Abusfullofnuns]

I can say that if my 4l80e loses a vss signal the trans behaves as your describing. I've experienced it twice, both times one of the vss sensors was unplugged. I'd say you need to determine why the vss code is present.

 

[ericcamaro]

i am having same issue, just did a full swap 5.3 4l60e all worked well in the doner truck, now stand alone harness, computer has been flashed for 8k, pass through code generator, and wont shift, , no codes besides i keep getting a maf sensor code, i do get a reading though my scan tool for the vss, 2nd and reverse, i can pull it down manually to first and manually shift to second, i have checked for power all is fine, any help would be great

I confirmed that it was a bad tune from the ebay tuner Leonard sparks. I got it put back to stock for vss signal and am using a Dakota Digital Sgi-5e to multiply the 8k signal to 128k and it's working great!

 

[onelowsonoma2]

i am getting a reading through my scanner from the vss

 

[ericcamaro]

i am getting a reading through my scanner from the vss

So was I, it was damn near on too. But the trans was still looking for 40 pulse per rev. And I sped up the signal so it looked like I was going 80mph with little loss on the trans and I got it to shift, that's how I knew the tune was bad.

 

[onelowsonoma2]

Your on too something there. Just talked to Brendan at lt1swap and he said he don't suggest them for electric shift transmissions. So I'll b ordering the multiplier..

 

[ericcamaro]

Your on too something there. Just talked to Brendan at lt1swap and he said he don't suggest them for electric shift transmissions. So I'll b ordering the multiplier..

It works but I will probably install a reluctor wheel and stock vss on my transfer case on the future. If you want to retain the pass thru and stock Speedo then the multiplier is the only way to go. I will have to switch to an electronic Speedo as well. Good luck