Reset ecu or entire truck system.

You have to remove the ground cables first regardless. Very dumb idea to take only the power cables off - touch ANYTHING metal with your wrench and you're making major sparks. Its essentially a dead short right on top of your batteries.

Ground cable will open the electrical system anyways.

 

That’s why I like a power shut off switch on the shakers . If I’m home for the week I shut off power.

 

I ordered a switch on the Peterbilt I got last year and I wish I would’ve had switches on all my trucks. It’s nice being able to cut the power off for weeks at a time and have the truck fire right up when I go back to work.

 

Why are you reseting? Did you get a code?

 

Might have to be recalibrated and not just turned off and on.

 

You may need to fill the DEF tank full to calibrate the level sensor.
I don't think unhooking the batteries will do anything.
What engine and make and year of truck?

 

It’s the positive that needs to be disconnected to reset, but of course negative needs to be off first. Also need to try to remove whatever is left by hitting the brakes couple times. But it may not help in your case regardless. Sounds like calibration issue or new thing is faulty too.

 

Is an ecu an ecm? Why not disconnect batteries?