We have a Tromm DLE2512W dryer that does not really work on sensor drying mode. When used it says how long and then stops in 5 to 10 minutes and clothes are not dry. Can take several times using the sensor dry. Once in a while it does work but generally not. Works fine on any other setting, just not with sensor dry. We replaced the sensors once because they thought that since we had used softener sheets in the dryer that the sensors had gotten ruined. Still did not work on sensor dry. Any help would be appreciated.

timed cycle mean dryer not on sensor dry mode. check wire connection on moisture sensor bars (i think you forget to put 2 wire connector put together). when you use other cycle dryer use moisture sensor to dry cloths so sensor not working dryer will stop in 5 minutes or so because dryer think there are no wet cloths to dry. hope this help you.

If you have chosen the manual mode and the dryer works well , then the fault can be with the sensor. need to check if there is false reading or if the control board has a issue.
Try to clean the unit and reset for a trial.

here is a copy of the service manual of that model   http://136.166.4.200/contents/Laundry/DLE2512/DLE2512_Service_Manual.pdf

I'd say yes, especially if you replace it yourself to avoid a service call. Top needs to come off (screws at back, then push top back 2 inches and lift off), remove front, remove 4 screws holding front bulk head / front rollers, slip belt off tension pulley, remove drum, reverse to install.

Yes that is your moisture sensor bar.

It can't verify dryness. Clean the sensors. Page 20

If you need further help, reach me via phone at https://www.6ya.com/expert/dan_73bbd84fe1d95b61

there are a couple of thermal fuses also that could be blown inside the back check these also

We have been having this same problem. I had tried adjusting everything that I could think of when putting a load of laundry in and got the exact same results as you. I would select the sensor dry and it would count down just like normal until it got to 6 minutes and then it would just run forever at 6 minutes.
My husband and I searched online all this afternoon and came across what seemed way to simple to work. We removed the lint filter, unscrewed the filter housing right inside the door of the dryer, and got to the sensors. We took a damp cloth and wiped them off very well to remove any and all buildup. We wiped everything down very well to remove any built up lint and/or dirt and put everything back in place as was before. We then unplugged the dryer for about a minute and then plugged back in. We put a load of already dry clothes into the dryer and started as usual with the sensor dry. It started out at the usual 41 minutes then skipped down almost immediately to 6 minutes and then a few minutes later I heard the most beautiful sound I have heard in a long time. The Beeper signalling that the timer had counted down to the end and was finished. It had worked. Thankfully. Hope this helps you also.

I called LG...they said to unplug the dryer for 5 min. to reset the timer ...this solved the problem.
They also said not to use dryer sheets during the sensor dry cycle as the coating on the dryer sheets causes the sensor to malfunction as it can't read the humidity level in the dryer.

Look inside the drum on the right side of the filter. You will see two metal strips, thee are humidity sensors. Wipe them down with soap and water. It worked for me. The info came from LG tech support.