Jam Codes are operational indicators on some laser guns that notify the officer if the gun is potentially being jammed. It is important to know if jam codes will affect you, especially in areas where the use of laser jammers is prohibited.
Below is the general status of jam codes on the laser guns used in the USA:
Kustom Prolaser III, II, I, ProLite
These guns do not have any type of JAM indicator.
LTI Ultralyte, Marksman
E07 = JAM (Along with JAM indicator on the display, and a distinct audible tone to indicate jamming).
It is rare to see E07. In all of the GOL jammer tests, no jammer we have tested has ever caused this code to be displayed. The only known jammers that trigger E07 are the older Lidatek LE-10 and Target LE-850. Newer, well-established jammers currently on the market will not trigger an E07. False alerts are rare, but sometimes bright sunlight can trigger an E07.
E04 = JAM
Stalker LZ-1 Version 1
An E04 code is very common to see on the version 1 Stalkers, even when targeting vehicles without jammers. This gun has the most "jam code false alerts" of any gun used in the US. This is possibly caused by light sources such as running lights or sunlight reflections. If an officer using one of these guns sees an E04, this isn't probably isn't suspicious by itself, since he probably sees it all the time.
Stalker LZ-1 Version 2
Stalker revised their guns, and on version 2 guns an E04 is very rare to see. No jammer that we have used this gun against triggers an E04. Most likely, this can only be triggered by "brute force" jammers such as the older Lidatek LE-10.
Laser Atlanta SpeedLaser
JA-1, JA-2, JA-3 in HUD (indicates potential jamming)
Jammer1, Jammer2, Jammer3 on LCD (indicates that a jammer is positively detected)
Laser Atlanta has taken jammer detection a step further by identifying the "type" of jammer. Jammer detection on the Laser Atlantas is a relatively new feature. Guns produced up until July 2005 did not utilize JAM codes. Guns produced after July 2005 should have jammer type detection, and Laser Atlanta can update the software in older guns to add this feature.
This gun is sometimes prone to "jam code false alerts", though not as often as the Stalker LZ-1 Version 1. But since the new updated Stalker LZ-1 has practically eliminated jam code false alerts, the Speedlaser now has the most "jam code false alerts" of any production laser gun. Something as simple as panning the road can cause these to display a jam code.
Currently, all laser jammers we have tested trigger jam codes on this gun. The good news is, the jam detection feature is not an always-on feature like on other guns: it has to be turned on via an "advanced menu" that is not visible by default when these guns are shipped. Furthermore, some users have reported that turning on jammer detection seems to cause a slight reduction in performance.