4L80e torque converter not unlocking issue.
02-22-2015, 07:51 PM
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4L80e torque converter not unlocking issue. I have a 2001 S10 Blazer with a 5.3/4l80e swap
Its got a stock PCM thats been flashed for the 4l80e
The conversion wiring harness was done by CPW for the motor and the transmission.
The truck had a stock 4l80e in it and an aftermarket stall *(Vortech 3400 multi disc )
Its been having an issue since put together, the truck will stall to 3400 rpms, sit there for a second and then it would go like normal. The "delay" would take about 1-2 seconds.
Thinking it was the off brand torque converter it was taken out and tested, tested fine , so put back in.
Same issue persisted.
Then I took that 4L80e and torque converter out in place of a built 4l80e and a yank 3600 stall.
Same issue persisted. ( it would then hang up right at 3600 )
I had a local tuner double check the bin file in the pcm - it looks correct for the 4l80e.
***While we data logged it running he noticed whats happening is the torque converter is not unlocking.***
Replaced the brake light switch.
Same issue persisted.
I have now taken it to a reputable person here locally to look at the wiring for the 4l80e - he said visually everything looks correct.
Im presently at a lose here and hoping someone here in the ls community might have an idea of where to look for an answer here.
Its got a stock PCM thats been flashed for the 4l80e
The conversion wiring harness was done by CPW for the motor and the transmission.
The truck had a stock 4l80e in it and an aftermarket stall *(Vortech 3400 multi disc )
Its been having an issue since put together, the truck will stall to 3400 rpms, sit there for a second and then it would go like normal. The "delay" would take about 1-2 seconds.
Thinking it was the off brand torque converter it was taken out and tested, tested fine , so put back in.
Same issue persisted.
Then I took that 4L80e and torque converter out in place of a built 4l80e and a yank 3600 stall.
Same issue persisted. ( it would then hang up right at 3600 )
I had a local tuner double check the bin file in the pcm - it looks correct for the 4l80e.
***While we data logged it running he noticed whats happening is the torque converter is not unlocking.***
Replaced the brake light switch.
Same issue persisted.
I have now taken it to a reputable person here locally to look at the wiring for the 4l80e - he said visually everything looks correct.
Im presently at a lose here and hoping someone here in the ls community might have an idea of where to look for an answer here.
03-14-2015, 05:01 PM
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I unpluged he main white wire harness from the rear of the transmission.
It seemed to go through first much quicker like it should , but would not shift out of first, even when trying to do it manually.
Does that shed any light on the situation?
03-14-2015, 09:30 PM
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I cannot believe that was second gear, wow! It accelerated quicker and had better response then it usually does. Guess there's definitely an underlying issue here.