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View Full Version : 4L80e converter lockup fix when letting off throttle?


chevyguy7802
September 27th, 2009, 04:03 PM
I just read on another forum it is a normal thing with 80e that when you let off the throttle the converter unlocks, is there a way to fix this? The converter locks up great and holds fine till I let off.
joecar
September 27th, 2009, 04:05 PM
I not 100% sure, but it seems the 4L80E control algorithm (for want of a better name) does this, whereas the 4L60E one does not.
ScarabEpic22
September 27th, 2009, 08:08 PM
Well for car 4L60Es this can be changed to not unlock the converter when off the throttle, truck 4L60Es unlock the converter regardless of settings. Solution? Run a car OS in the TCM (if you have 2 modules).

For the 4L80E, not sure if you can do it as Im not aware of any car that used it. Wonder if anyone has found the area in the hex code to maybe make a .cax to enable/disable this (and would be great for LS1 cars too).
joecar
September 27th, 2009, 10:00 PM
Well for car 4L60Es this can be changed to not unlock the converter when off the throttle...Erik, do you mean with the apply/release tables D1001-6, or is there another table...?
ScarabEpic22
September 28th, 2009, 07:33 AM
Erik, do you mean with the apply/release tables D1001-6, or is there another table...?

Im honestly not sure Joe, Ive just heard that car OSs leave the converter locked (or can be setup properly to) while if the same tables in a truck OS dont keep it locked with 0 TPS. I know for the TBSS the stock TCM OS unlocks the converter but if you run a GTO OS in the TCM it keeps it locked.
chevyguy7802
September 28th, 2009, 01:51 PM
Thanks for the replys guys, a guy on another forum said he got the 4l60e tune to work with the 80e without the segment swap and he said also that it does not unlock with the 4l60e tune. But idk if Id do it that way lol. The cax file would be a great idea!
slow67
October 2nd, 2009, 03:33 AM
Erik, do you mean with the apply/release tables D1001-6, or is there another table...?
Yes, tables D1001-6. Even when commanding it to lockup below 5% throttle, it still unlocks in the 80E cal.

Thanks for the replys guys, a guy on another forum said he got the 4l60e tune to work with the 80e without the segment swap and he said also that it does not unlock with the 4l60e tune. But idk if Id do it that way lol. The cax file would be a great idea!
Yeah I'm the one who got my 80E to run on the 60E cal. Works great (is more useful for 98 Cals, LT1 cars, GTOs, etc.). My car was just the mule.
joecar
October 2nd, 2009, 04:38 AM
...
Yeah I'm the one who got my 80E to run on the 60E cal. Works great (is more useful for 98 Cals, LT1 cars, GTOs, etc.). My car was just the mule.
http://www.ls1tech.com/forums/automatic-transmission/1181364-4l80-tune-no-longer-required.html

I saw that, good job, clever...:cheers:

Did the PCM throw any codes for missing 3-2 solenoid and missing TCC Enable solenoid...?
slow67
October 2nd, 2009, 05:26 AM
I saw that, good job, clever...:cheers:

Did the PCM throw any codes for missing 3-2 solenoid and missing TCC Enable solenoid...?

It certainly did. It also eventually threw a code for transmission component slipping, because I don't have access to the gear ratios (when the TCC is locked up, and I don't have EFILive yet). I fixed that code, but I may end up upping the minimum diagnostic temp for P1870 to something above 250*.