The frequency used by Dodge on the Vipers is 315Mhz. In Indy we have a television tower close by that transmits 260Mhz and it prevented me from being able to use the remote at all. Oddly, the radiation pattern off the transmission tower is shaped in a way that the greatest ground interference is not directly below, but some miles away from the tower. Consider this when you evaluate where you have FOB problems.
My solution was twofold. First, my year Viper had the receiver antenna within the EEM initially. A TSB alarm EEM update changed the antenna to a wire type that was placed under the console. I found it and rolled it up inside a 35mm film cap. Used heat shrink tubing to seal and attached it to the inside of the windshield, at the lower drivers side A pillar base. Now, not only do I have exceptional range when not near the tower (much further than before), but when I am near the TV tower I can place the remote right on top of the antenna to overwhelm the conflicting frequency.
The other solution, which I haven't tested yet, was to attach a length of wire to the internals of the EEM in a way that attenuates the 260Mhz TV frequency. Haven't tested yet as plan 1 works we enough by itself.
One thing I tried that didn't work was to increase the power of the FOB. Found that the increased power was insufficient to overwhelm the TV frequency.
Newer Vipers have their antenna inside the dash wiring harness, rather then strung by itself within the console. You can replace it with a solution like mine if you wanted to take the time.
Why Dodge made the Viper's FOB 315Mhz while almost all other cars are (from memory) in the 400's I do not know. Wish I did.
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Just found this from an old post I did a few years ago:
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All Gen I's have antennas internal to the SAM module. 1996 GTS's also have an internal antenna in their EEM, but if the EEM TSB upgrade was performed, an external antenna was taped under the console as part of the upgrade. 1997's have the under console antenna and 1998 on up have external antennas but they are embedded in the instrument panel wiring harness.
If you have the under console antenna, you're in luck. You can remove one screw from the driver side of the console, (by your right hip if you're sitting in the seat) and gently pull the antenna out from underneath. You can easily find the antenna wire if you look under the dash at the EEM (above the gas pedal mounted on the side of the trans tunnel). The antenna is the thickest black wire there. It's thin gauge coax. If you pull this out, you'll find about 32 inches of coax with a 13 or so inch unshielded antenna at the end. If you take the coax, run it up to the drivers "A" pillar, then flat coil the unshielded section only into the top of a 35mm film canister and wedge it down between the windshield and the dash, you have:
200 foot range in non RF interference conditions (versus the stock 23 feet)
2 ~ 3 foot range in severe RF conditions (versus zero)
The advantage of this antenna layout is that you can almost directly connect the FOB with the EEM by placing the FOB's antenna (which is from the 9 to 12 o'clock position looking at the FOB face) on the windshield directly over the coil. This tends to overpower ambient RF and flood the EEM with your FOB signal. In the normal straight antenna layout, you can not get the weak FOB transmitter close enough to over power the ambient interference.
Since I don't have a GENI, I can't provide much help on how to attach an antenna to the SAM module. On 1998+ models, I do have instructions on how to open the EEM connector to add an antenna, but since I don't have one, I can't verify how accurate they are. Either way, at least you have a start on a possible solution.
