Stuck in 3rd - 4L60E '95

[gothicsera]

My truck seemed to be shifting fine when I drove it home the other day. But this morning, on the way to work, it seems to be stuck in 3rd gear.

Also when I first jumped in it the speedo, tacho and gear indicator weren't functioning. After a few miles the instrument cluster started working again but was still stuck in 3rd gear.

Any ideas?

 

[gothicsera]

So, went out for another drive and it started working properly again. So guessing dodgy connection somewhere on the 12v solenoid supply meaning the transmission is going into limp mode.

 

[df2x4]

The fact that the speedometer failed when you had the problem leads me to believe that it may be related to the vehicle speed sensor on the transmission.

 

[gothicsera]

The tacho stopped working as well.

I played around with the transmission fuse and it started working again....

 

[Supercharged111]

It's 12V power to the trans causing it to be stuck in 3rd. We're it a 4L80, it'd default to 2nd.

 

[gothicsera]

Fixed this with a new ignition switch.

I found that if I keyed on/off a few times I could get power to the dash and trans fuse. Replaced the ignition switch and it's now working perfectly and has been for a few weeks.