factory automatic running board sensors??

[yoyoman05]

i have a 2019 longhorn with factory running boards, when i open the door they deploy as they should but about one in every 4 or 5 times they deploy and go right back in and the message on the dash says possible obstruction please check your surroundings.. even if im in a parking lot and no one is parked next to me. this makes me think there is a sensor bad or blocked.. does anyone know of such a sensor and its location?

 

[yoyoman05]

after getting under the truck i found that once the running boards are retracted they touch this canister part? does anyone know what this is? its on both side frame rails. not sure if this has anything to do with the issues im having seeing that it only touches when its retracted and they stay in fine.

 

[Rick J]

Those are Active Tuned Mass Modules, ATMMs, which are essentially little cans bolted to the frame rails on either side of the truck, with solenoid-activated weights inside.

As the HEMI engine’s Multi-Displacement System kicks in, and sends the truck into four-cylinder mode, an underhood sensor picks up unwanted vibrations, and triggers these ATMMs to shake their internal weights in a way that’s 180 degrees out of phase with the engine’s unwanted vibration, thus canceling it out and yielding a smooth experience for occupants.

Don't have anything to do with the running boards.

 

[yoyoman05]

Those are Active Tuned Mass Modules, ATMMs, which are essentially little cans bolted to the frame rails on either side of the truck, with solenoid-activated weights inside.

As the HEMI engine’s Multi-Displacement System kicks in, and sends the truck into four-cylinder mode, an underhood sensor picks up unwanted vibrations, and triggers these ATMMs to shake their internal weights in a way that’s 180 degrees out of phase with the engine’s unwanted vibration, thus canceling it out and yielding a smooth experience for occupants.

Don't have anything to do with the running boards.

Thank you very much..when the shop installed my body lift it looks they adjusted these downwards to clear the running board. Does that matter?..i never feel any vibration..can i move these a couple inches down on the frame rails?

 

[Rick J]

Thank you very much..when the shop installed my body lift it looks they adjusted these downwards to clear the running board. Does that matter?..i never feel any vibration..can i move these a couple inches down on the frame rails?

Sorry, I don't know if they can/should be moved. Guess you could try and see if it make any difference. They only come into play when MDS (Eco Mode) kicks in.