International just released a reflash that will allow you to drive the vehicle with a faulty sensor installed, contact your local dealer for the reflash

Lots of school buses are down also. Across all the makes. Freightliner, IHC, and Blue birds, since all run Cummins with def now

Pull the rubber boot off the bottom, wash the “little mirror looking” part with dawn dish soap let dry, put boot back on and reinstall out in parked regen and go from there

QLS sensors are a problem across all models. If you take time to do some reading, regardless of the model, they are very hard to find. It’s not unique to Navistar. The tank and sensor are not designed by Navistar either.

My QLS sensor just went out on a 2020 LT Truck... Had to have truck towed to nearest dealership where they already have 5 trucks ahead of me waiting for the same part because the sensors are on backorder. Was told that they have had trucks waiting there for the sensor to come in for 4 weeks already. International needs to be given a class action suit for this as it is disrupting many companies their ability to operate effectively. Can't believe it is taking them this long to make enough replacement QLS sensors for this known issue. Not happy with them at all. 🤬

does this make sense Ok, here's the scoop... They are experiencing premature failure due to stuck open heater control valves. The heater control valve is the coolant control valve that is used to allow hot engine coolant to circulate through the tank on very cold winter days to prevent DEF freeze ups. These valves will get stuck open and allow hot engine coolant to over heat the DEF tank and cook the QLS to the point of failure. They aren't designed to be in that environment. So once spring and early summer hit, along with higher temps, these sensors are dropping like flies. Currently, Navistar is back ordered over 4000 units. There are currently two different styles of heater control valves. The one with the square solenoid is the bad one. We are replacing all those with a newer Parker made valve with a round solenoid. If you are replacing a QLS, replace that old style heater control valve regardless.

Lots of county trucks are down with this issue. Dealer says we might get trucks back to is next year. No parts

international knows that they have a problem with this. It is very concerning that they have yet to come up with a solution. I have two 2017 IH trucks that have had their DEF QLS sensors replaced 8 times each under warranty, and one of them is over for #9 now. My 2018's and 2019 also have had multiple failures.

LA CALIDA DE LAS PIEZAS QUE INTEENATIONAL VENDE VIENE CON MUCHO DEFECTO DE FABRICA EN LA COMPAÑIA QUE TRABAJO ESTAMOS ESPERANDO UNAS 17 GUAGUAS POR LOS SENSORES Y LA VALVULA DEL HEATER Y LOS ALTERNADORES NI SE DIGA LA CALIDA ES UNA BASURA.

Is the same def sensor a problem on the trucks with the Cummins engine?. Do both engines use the same sensor?

I have a 2023 model that just says low def and it’s full. So international is still putting the bad def sensors on.

I have an issue with coolant leaking,, do I need to replace the quality sensor immediately??

I was looking on forums about the def sensor failing. Seems like the coolant lines are reversed causing the failure . Does that sound like something that could be causing the failures?

Compadre! Tengo un LT 2020 y tengo el problema que de que se activaron los codigos que le falta def pero esta el tanque lleno y me redujo la la torcion a 40% que problema es?

Does the international lt with Cummins engine have the exact after treatment system like the one with a26 ?? Do you recommend the one with the Cummins engine for owner operator?? Hiw can I contact you??

Are they still using the same sensors on new models?

has international started using a different sensor on newer models?

👍👍👍

DEF delete