Truck shifting in an out of gear

[Nw2000]

Hey everyone. I have a 1995 c1500 and the issue I am having is when I’m cruising at light throttle the transmission constantly downshifts and up shifts. I replaced the tps sensor a few years ago but could it possible be that or is the transmission acting up? Thank you for any help.

 

[thinger2]

Hey everyone. I have a 1995 c1500 and the issue I am having is when I’m cruising at light throttle the transmission constantly downshifts and up shifts. I replaced the tps sensor a few years ago but could it possible be that or is the transmission acting up? Thank you for any help.

Probably not the issue.
But, torque converter lockup actually runs through your brake light switch on a 4l60e.
Make sure your brake ligjts are working correctly.
I had a short in mine that would kick it out when they got wet or if I stood on the brake pedal.
I only figurred it out because I put new taillight bulbs in and backed the truck up so the ass end was pointing towards the glass windows at Oreillys and when I hit the brakes the taillights flickerred and went out but came back on when I let off a little bit.
It was bad grounds at the tail and a bad brake switch

 

[Nw2000]

Probably not the issue.
But, torque converter lockup actually runs through your brake light switch on a 4l60e.
Make sure your brake ligjts are working correctly.
I had a short in mine that would kick it out when they got wet or if I stood on the brake pedal.
I only figurred it out because I put new taillight bulbs in and backed the truck up so the ass end was pointing towards the glass windows at Oreillys and when I hit the brakes the taillights flickerred and went out but came back on when I let off a little bit.
It was bad grounds at the tail and a bad brake switch

I’ll have to check that out thanks. I would’ve attached a video if I could.

 

[Nw2000]

Probably not the issue.
But, torque converter lockup actually runs through your brake light switch on a 4l60e.
Make sure your brake ligjts are working correctly.
I had a short in mine that would kick it out when they got wet or if I stood on the brake pedal.
I only figurred it out because I put new taillight bulbs in and backed the truck up so the ass end was pointing towards the glass windows at Oreillys and when I hit the brakes the taillights flickerred and went out but came back on when I let off a little bit.
It was bad grounds at the tail and a bad brake switch

Confirmed brake lights do in fact work. This only started happening when I started driving it again after putting it up for the winter. Perhaps it sitting there for a few months could have caused it?

 

[Alteca]

I had a bad ground cause an issue like this

 

[Nw2000]

I had a bad ground cause an issue like this

Which ground was it? I could go ahead and inspect it tomorrow.

 

[Alteca]

Which ground was it? I could go ahead and inspect it tomorrow.

It ended up being the battery terminal wasn’t tight enough, oddly enough the trans coming in and out of gear was the only problem it caused

 

[Nw2000]

It ended up being the battery terminal wasn’t tight enough, oddly enough the trans coming in and out of gear was the only problem it caused

I’ll definitely check that out.

 

[Caman96]

Never hurts to pump out and exchange for new fresh fluid.

 

[Schurkey]

I have a 1995 c1500 and the issue I am having is when I’m cruising at light throttle the transmission constantly downshifts and up shifts. I replaced the tps sensor a few years ago but could it possible be that or is the transmission acting up?

Connect a scan tool, find out what the computer is trying to tell you.

Not only do you need to verify engine performance, I'd want to interrogate the transmission, too. Fluid temperature, shift adaptation, and anything else that seemed relevant.

Confirm: this is a SHIFTING problem, not a TORQUE CONVERTER CLUTCH problem?

Never hurts to pump out and exchange for new fresh fluid.

...and filter, and clean the inside of the pan.