Quote:
Originally Posted by 1320 Besides the wiring differences, there are pcm differences regarding the vss. About all a 4l60 tune will do on a 4l80 is 3 rd and reverse i think. You could move a car in a shop, and thats about it. Its painless anyways to just have the 4l80 os system patch done. |
Thats because the Solenoid B operation is exactly opposite of the 4L60E. It detects a fault (the 3-2 solenoid and TCC enable solenoid don't exist) and goes into limp home mode.
This turns off all of the solenoids and puts you in 2nd gear (on a 4L80e, a 4L60e limp is 3rd).
If you disable the codes (P0785, P0740) it
shouldn't detect a fault. All of the electrical hardware is the same (some years even share part numbers).
Solenoid A operation is the
same on/off sequence. Solenoid B operation is the
EXACT OPPOSITE.
In theory (I will be testing it this weekend) if you hook up a 5 pin relay and use the Normally closed pin to ground solenoid B (pin 87a on the relay) it will reverse the operation of solenoid b, making it operate with the same commands as a 4L80E.