4L60 - 4L80 P1860 Code No Lockup
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Teching In
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4L60 - 4L80 P1860 Code No Lockup Wondering if some guru's can help me out. Have a 5.3 in a 71 GMC pickup. Was originally a P01 4L60 PCM I had tuned and revised by a local reputable tuner but long story short he stopped communication after some disagreements in fuel trim diag early on. So I guess I'm on my own now. The truck runs, drives beautiful and I'm generally happy with the tune for now.
Did the proper wiring mods to swap to the 4L80. Double, triple checked my work. When the ISS is plugged in I get a P1860 TCC PWM Electrical code and as far as I can tell, no converter lockup. When it's unplugged I get an ISS Circuit code, lockup at 40mph, unlock at throttle lift and extremely hard shifts, so the PCM is seeing the ISS, the lockup solenoid works and the pcm is at least partially segment swapped. Problem is when the ISS is plugged in I can't get it to lock up, at least not at a reasonable speed (haven't had it up over 65mph yet). I believe it's tune related, hoping someone can help point me in the right direction?
TIA!
Did the proper wiring mods to swap to the 4L80. Double, triple checked my work. When the ISS is plugged in I get a P1860 TCC PWM Electrical code and as far as I can tell, no converter lockup. When it's unplugged I get an ISS Circuit code, lockup at 40mph, unlock at throttle lift and extremely hard shifts, so the PCM is seeing the ISS, the lockup solenoid works and the pcm is at least partially segment swapped. Problem is when the ISS is plugged in I can't get it to lock up, at least not at a reasonable speed (haven't had it up over 65mph yet). I believe it's tune related, hoping someone can help point me in the right direction?
TIA!
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From: BERWICK PA
The code is an electrical code meaning either your wiring is not properly does for the swap or the segment swap is wrong or incomplete.
I would verify the wiring first, THEN SEGMENT SWAP, You will likely get more help with the segment stuff in the tuining area of the forum.
But the issue is electrical or tuning in nature. Personally with that particular code I think the segment swap is wrong or incomplete.
I would verify the wiring first, THEN SEGMENT SWAP, You will likely get more help with the segment stuff in the tuining area of the forum.
But the issue is electrical or tuning in nature. Personally with that particular code I think the segment swap is wrong or incomplete.
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Thread Starter
Teching In
Joined: Jul 2024
Posts: 3
Likes: 1
The code is an electrical code meaning either your wiring is not properly does for the swap or the segment swap is wrong or incomplete.
I would verify the wiring first, THEN SEGMENT SWAP, You will likely get more help with the segment stuff in the tuining area of the forum.
But the issue is electrical or tuning in nature. Personally with that particular code I think the segment swap is wrong or incomplete.
I would verify the wiring first, THEN SEGMENT SWAP, You will likely get more help with the segment stuff in the tuining area of the forum.
But the issue is electrical or tuning in nature. Personally with that particular code I think the segment swap is wrong or incomplete.
I'll check over on the tuning side. Maybe I can upload the tune for somebody to take a look at. I could see the tune being the common denominator considering the issues I've dealt with to date.
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Joined: Jul 2022
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From: Alaska
OP: "the lockup solenoid works and the pcm is at least partially segment swapped."
I had same problem. 4L80 swap into half ton. Partial segment swap, all forward speeds shifted, TCC totally flaky.
You need to segment swap TWO items: the tab for trans diagnostics has to be included.
I had same problem. 4L80 swap into half ton. Partial segment swap, all forward speeds shifted, TCC totally flaky.
You need to segment swap TWO items: the tab for trans diagnostics has to be included.
Thread Starter
Teching In
Joined: Jul 2024
Posts: 3
Likes: 1
OP: "the lockup solenoid works and the pcm is at least partially segment swapped."
I had same problem. 4L80 swap into half ton. Partial segment swap, all forward speeds shifted, TCC totally flaky.
You need to segment swap TWO items: the tab for trans diagnostics has to be included.
I had same problem. 4L80 swap into half ton. Partial segment swap, all forward speeds shifted, TCC totally flaky.
You need to segment swap TWO items: the tab for trans diagnostics has to be included.
