Search found 2 matches
- Fri Oct 08, 2021 1:20 pm
- Forum: General Motors
- Topic: Weird 4L80E problem
- Replies: 5
- Views: 6064
Re: Weird 4L80E problem
If I drove in drive, it would set code 39. TCC would lock up and work just fine. When in overdrive, it would shift into 4th and the converter would lock up. After a mile or so , the tranny would shift down to 3rd and the converter would not lock up. I would have codes 39, 68, 85, 86,and 87. I just h...
- Thu Oct 07, 2021 4:47 pm
- Forum: General Motors
- Topic: Weird 4L80E problem
- Replies: 5
- Views: 6064
Re: Weird 4L80E problem
I had a similar problem on my 93 motorhome disabling 4th gear and the TCC lockup. For some reason the only way I could reset the codes was to remove power from the PCM for an hr. I replaced both shift solenoids and no luck. I finally replaced the input speed sensor and the tranny works perfect again.