About a month ago my "service 4wd" light began to come on then go out. Then about a week later it came on all the time with the "security" light coming on also about thirty seconds later after a chiming sound. The LEDs on the transfer case mode selector switch also would not light (AWD).

I tried to disconnect the battery and when I reconnected it the instrument panel was normal again and the 4WD selector functioned normally again. after a week of running normal the same thing began again. I disconnected the battery again but this time the "service 4WD" light did not come on and the transfer case mode selector LEDs do not operate at all! But the "security" light comes on immediately after a chiming sound.

I would like to get some comments as to what electronic component is malfunctioning. Any ideas?

 

the security system is built into the CTM, and afaik controls which error lights on the dash come on, however i do not know if it has anything to do w/ the transfer case modules

however the transfer case control module (tccm) monitors the transfer case and tells the CTM when there is an error, i would say it is one of the two.