TCC Constantly Locking and Unlocking
#1
TCC Constantly Locking and Unlocking
I've done the Flex Fuel sensor install using OS 12216125. After locating a 4l80e file that uses the same OS and performing a segment swap the trans would not downshift from third to first when coming to a stop. Hptuners support sent me a different file which solved the downshift problem but now the TC will not stay locked in 4th and when the shift selector is in D3 the TC will lock even thou in the tune it should not lock in third at all. It will constantly lock then unlock until I let off the gas to get below my targeted lockup speed. Does anybody have any suggestions?
#2
Here some more info: I got code P1810 - Trans Fluid pressure switch. My trans has less than 4000 miles on it after a complete rebuild. Could this switch go out that fast? Here a thread from ls1trucks that describe my exact symptoms.
http://www.ls1truck.com/forums/diagn...1810-help.html
http://www.ls1truck.com/forums/diagn...1810-help.html
Last edited by Monte4ever; 05-20-2017 at 06:24 PM.
#3
Here's a log of the TC locking and unlocking. It starts on frame 17:48:55. After it did this a few times I used the scanner controls and hit lock TC solenoid. The scanner did not lock the TC solenoid but some how it stopped the on and off locking until I went below the lockup speed. I tried it again and it repeated the on and off locking until I once again commanded the TC solenoid to lock which stopped the repetitive locking. Looking at the channels the PCM is commanding the TC solenoid to lock and unlock. IDK what's goin on.
Edit: Now I'm also getting a new code - P1637. This code says it's current and the P1810 code is labeled history.
Edit: Now I'm also getting a new code - P1637. This code says it's current and the P1810 code is labeled history.
Last edited by Monte4ever; 05-21-2017 at 12:04 PM.
#4
Fixed
This goes to show you to never over look the simplest things. I re-adjusted my linkage and took it for a quick around the block drive right after a few days ago and it still would not go into overdrive so i parked it. Well, this morning I was headed to the trans shop and what do you know - I had overdrive SMH. I guess it took a minute for the ECM to pickup on the adjustment. I've been driving this car for years without touching the shift linkage but when i did check it it was off just under 1/8". I hope this problem is behind me.
Last edited by Monte4ever; 06-07-2017 at 07:54 AM.
#6
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keep me updated on this. I have a friends that has a very strange TC lockup issue as well. I have a few theories but am not sure. Does the trans ever shift inconsistent when doing this or does the take off feel like it has a larger stall than it does at times?
#7
Trans shifts normal when cruising. It hits all gears very well although now it doesn't shift from 2nd to 3rd during WOT as it did before. I haven't changed anything in the tune as far as WOT shift points from last year when it worked. It will be a couple of weeks before I get to the transmission shop but I will update this when I do.
Last edited by Monte4ever; 06-10-2017 at 12:05 PM.
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#8
UPDATE:
After using two 12216125 files to do a segment swap from looks like the third one I found is a winner. The TC no longer goes in and out of lock and is shifting through all gears beautifully. I drove it twice and everything worked 100% better. Now I just gotta work on when I want it to lock but so far the worst looks to be over................hopefully.
After using two 12216125 files to do a segment swap from looks like the third one I found is a winner. The TC no longer goes in and out of lock and is shifting through all gears beautifully. I drove it twice and everything worked 100% better. Now I just gotta work on when I want it to lock but so far the worst looks to be over................hopefully.