viper 791 remote start trouble

ok my friend wants me to take a look at his remote start cause its not starting up anymore... it used to work just fine... but now it cranks... starts.. and keeps cranking... (from what he's told me) i havent gotten around to actually taking a look at it, but i want some opinions on what it could be and how to fix it.  i already have a few ideas of what it could be.. im thinking it could be either the tach wire got disconnected or tampered with... or the remote start satelite relay or whatever it is.. is damaged.  he says the car starts up... then continues cranking once its running... anyone else have any ideas and suggestions before i take a look at it? any help would be appreciated. thanks.

did he look at the shut down diagnostics. what make model of car he has.

its a late model mazda 3 five door hatch, i believe its an 05.

what does the shut down diagnostis read.

havent been able to look at the car myself, ill check the diagnostics when he brings it to me later this week.

1 Start a car with a key 2 press and hold Valet/program switch/ 3When a led will light constant the tach signal is learned. Done .ati

the tach was already learned, i see no reason why it would have reset, of course ill know a lot better once i take a look at it this week...