coolmyst9,

First, make sure in the SETUP screen that you have the specific expression pedal set to adjust the FX UNITS you want it to control.

Do you have a manner of reproducing the problem that your are experiencing, or is it pretty random? Is the problem persistent on your M13?

You may want to try resetting the M13:

Press and hold Looper Controls to enter the setup menu. In FX UNIT 4, turn the Model Select knob until the corresponding display shows RST FACT. Press down on the Model Select knob twice to complete the reset.

You can also try re-installing the flash memory of the M13 from the instructions at the following link:

http://line6.com/community/docs/DOC-1395

Regards,

Line6Hugo

I am also having problems getting my expression pedal to work right with the M13. It is a  Korg EXP-2.

When I first plugged it in and tried it on one of the factory scenes that had several effects on at once, it changed several parameters at the same time  on all of the effects. For instance, the volume and tone and mix all went up and down on several of the effects at the same time.

When I try to set it to control just one of the parameters on a particular effect, it works one time but it goes past full volume in the window when I push the pedal all the way down, then it doesn't work at all.  I have version 1.07. Maybe it is a bug that needs fixed but I am guessing I need a Line 6 expression pedal for it to work right.

The store bought my M13  from did the update from 1.04 to 1.07 for me. I told them I didn't want it if it didn't have the newest firmware. They said they'd be glad to do it and that it was easy. 6 hours later the keyboard tech and guitar effects salesman were still trying to figure out how to do it. They ended up  calling Line 6 support and having them walk them through it. They needed a midi to USB cable and had to install some kind of software on their Mac computer, and some kind of driver I think they said. They said they couldn't believe they had such a hard time figuring it out and getting it done. I am really glad they did it. I am dreading the day that I try to update to the next upcoming firmware update.

Here's everything I could find in the advanced manual.

Expression Pedals
In LCD 1 you set up your expression pedal assignments. Any or all 4 FX Units in the M13
can be controlled by an expression pedal. You can use up to 2 pedals at once. Each can be
assigned to an FX Unit or the Looper. You have 3 selection choices here: Pedal 1, Pedal 2,
or Off. Knobs 1 & 2 set the assignments for FX 1 & FX 2, Knob 3 sets the assignment for
the Looper, and Knobs 4 & 5 set the assignments for FX 3 & FX 4.
*Looper pedal control is a global setting. FX pedal control settings are saved per Scene.
See Chapter 2 for more details on how to set up heel and toe expression pedal settings.

If you use an expression pedal in your rig, you should know that all of your heel & toe pedal
assignments can be stored in a Scene, so many unique combinations are possible. Here are
some details explaining Momentary Scene mode and Latch Scene mode.

Expression Pedal Control
You can optionally control Looper EQ, Playback and Overdub Levels with an expression
pedal by setting up your heel and toe values and assignments in Setup Mode, as described
in Chapter 1, Page 2. Also see Chapter 2 for more expression pedal info.

All the very best!

Terry