MechWarrior Online Wiki

Equipment Overview
Tech Base: Inner Sphere 
Equipment Type: Electronics 
Tonnage: 1.5 tons
Critical Slots: 2  
Item Health: 3  
Cost: Cbill.png 400,000  
Sell: Cbill.png 200,000  


Electronic Countermeasure Suites. Guardian, Angel, Infiltractor, etc - A device that jams enemy sensors to a degree. In the Inner Sphere, the most widely-deployed ECM Suite is the Guardian, but the experimental Angel ECM Suite can also be seen.

Mechwarrior Online[]


ECM Range Readout

Mechs that can mount ECM[]

Currently only the following 'Mechs can mount ECM: {{#ask: |format=table |mainlabel=BattleMechs Capable of Mounting ECM }}

Disrupt Mode[]

By default, the ECM is in “disrupt” mode. While it is in this mode, it creates a bubble of sorts that scrambles enemy communications and sensor systems. ECM will also hide friendly 'Mechs within its range. Mechs carrying an ECM in disrupt mode are marked with an ECM icon.

ECM HUD icon

All friendly Mechs (including the one with the ECM) within the range of an ECM in disrupt mode (180 m) are ‘cloaked’ from enemy sensors. Mechs that are hidden in this manner are marked with a symbol that looks like an eye.

When a Mech is hidden by a friendly ECM:

  • Enemy Mechs will have to come within 1/4 the normal distance (200 m instead of 800 m, by default) for hidden Mechs to show up on their battlegrid and HUD.
  • The Beagle Active Probe will extend this range.
  • It takes twice as long to achieve a missile lock against a hidden Mech.
  • Narc beacons will stick to hidden Mechs, but they won’t provide their normal bonuses until the Mech leaves the ECM’s range.
  • Artemis IV does not provide any bonuses against hidden Mechs.
Hidden 'Mech Icon

When you enter the range of an enemy ECM in disrupt mode, your Mech will be cut off from communications with your teammates and some of your targeting equipment will cease to function. Mechs that are within the field of a hostile ECM are marked with a symbol that looks like low signal bars.

When your Mech is disrupted by an enemy ECM:

  • You cannot share any targeting data with the rest of your team, and vice versa.
  • You cannot achieve any missile locks.
  • Your TAG laser can still fire but provides no bonuses.
  • Your battlegrid and targeting information will flicker.

Low Signal Strength[]

Low Signal Strength Icon

Between the ECM’s 180 m range, and the 200 m range for detecting Mechs hidden by ECM, there’s a 20 m radius band where you can detect a hidden Mech, target it, and get a missile lock and/or share the targeting with your teammates.

If you are not being disrupted by an enemy ECM, any hidden Mech on the other team that you hit with a TAG laser will be revealed as if it wasn’t being hidden. This allows you and your teammates to target and lock on it for as long as you can keep the TAG beam trained on it.

If you press the button to toggle the mode of your ECM (‘J’ by default), you can switch from “disrupt” mode to “counter” mode and back again.

Counter Mode[]

Counter Mode Icon

Counter mode provides none of the benefits of disrupt mode. What it does do is counter enemy ECMs that are in disrupt mode.

Your ECM in counter mode will:

  • Cancel the effect of one enemy ECM on Mechs (friendly or enemy) within range of your ECM (180 m)
  • However, two enemy ECMs affecting the Mech would require two counter ECMs, three would require three, etc.
  • Completely cancel all effects of an ECM in disrupt mode equipped on an enemy Mech that is within range (180 m)
  • Mechs countered in such a way have their ECM symbol replaced with a crossed out version.
  • You can only counter one enemy ECM in this manner.
  • I.e. If there are two enemy Mechs with disrupt mode ECMs in range, one will be countered while the other will function normally. But two counter ECMs will counter two disrupt ECMs, etc.
Countered ECM Icon

Coming into the game at the same time as ECM is your Mech’s status bar. This is a series of icons on the right hand side of your HUD that denote various effects your Mech is experiencing. Currently you’ll see if your Mech is being hidden by a friendly ECM (including your own), if your communications are disrupted by an enemy ECM, and if your ECM is being countered by an enemy. In the future, more status indicators will be added to this area.[3]

Countered ECM Icon

How ECM Can Be Defeated[]


Hitting a target that has ECM engaged with any PPC-styled weapon will disable ECM for 30 seconds. Repeated hits with PPC fire does not extend the time, but only restarts the time. IE, Hit with PPC #1 sets timer to 30 seconds. 5 seconds later, hit with another PPC. Timer is reset for 30 seconds and not extended to 55 seconds.


BAP will completely negate one enemy ECM within 360 meters. A single Beagle Active Probe may still be overwhelmed by two or more enemy ECM though.


Shooting a 'Mech with TAG from outside it's protector's "ECM-sphere-of-influence" will allow it to be targeted.

ECM Hardpoint[]

ECM must be equipped to a fixed hardpoint. Destroying the section of the enemy 'Mech that contains the ECM, or scoring a critical hit on the ECM, itself, will disable it. Destroying the enemy 'Mech will, of course, also work.


  • December 4, 2012: Guardian ECM added to game.


  1. Piranha Games\MechWarrior Online\Game\GameData.pak\Libs\Items\ItemStats.xml
  2. How screen shake is calculated
  3. Guardian ECM Suite Forum post