Tranny not going past 1st gear

[CoCoFX]

Hello, last night I was driving up a small light hill and my truck just reved up to 4000rpm I let go of gas pedal and stepped on it again and it reved up again, I stoped and took off and it was not jumping to next gear just stood reving up, I pulled over and turned off the truck waited about 30 seconds turned back on and everything was back to normal like nothing happened, I even feel like it's shifting better or I'm just crazy, lol. Anyone here had this issue or knows about a fix?

 

[Themechanic]

Check your transmisdion fluid. It could have been a sticky shift solenoid not letting it go into 2nd gear. Only way to tell would be to have it scanned with a scan tool for tranny codes that might have to do with the solenoid.

 

[shadow191]

I had a similar situation when fluid was low. It would "hang up" in a gear and delay the upshift. If you stay on it, it will eventually shift. Added fluid and it went away.

Or there is an issue with your valve body solenoids. I had another issue where a solenoid failed and I could get it to reset by shutting the car off or using my code scanner to clear the fault. Hopefully it's not the actual valve body because if it is, you need to rebuild/replace it. Start with the fluid. I think if it was the actual valve body, it would throw a code. But mine started with the slow shifts and even after topping off the fluid, the solenoid eventually failed.