2009 kia sportage always in 4x4 has a 4x4 lock switch in dash that lights up in dash when pressed and light goes off when u press it again seems to work no codes found

Don't think there is a switch have you tried replacing batteries in key fob if they are run down maybe there not enough power to open boot

could be the switch, usually located under the dash, the brake pedal (when released) should make contact with the switch pushing it in, when you press the pedal it will release it.. it may be sticking or just bad
this is where i would start

Well Im hoping that by telling you to check your cruise control wiring and vacuum routing for broken, unplugged wires or vacuum hoses you just might find that a simple vacuum line is in need of attention. good luck

possible wiring problems could be a bad dash light dimmer switch also

Ok, this is probably going to sound greek if you have no automotive experiance, so here goes:

There are 2 possibilities I can think of at the moment depending on your 4wd system, however there are several things that can cause this

If you have a Push button 4wd (you push a button or turn a knob) the system engages using actuators or sylinoids meening you turn the 4wd on, the switch sends power to the selector option (high and low) and the 4wd light on the dash. the selector determines where the actuator/silenoid engages (either high or low) in the transfer case. However the actuator or silenoid can be faulty and yet the system will say 4wd is on because the switches still sending power to the 4x4 light

The next setup is the manual linkage set up, and given the year of your kia I doubt you have this setup However I am going to go through it anyway.

With a maual linkage setup you engage the trasfer case maualy using the 4wd shifter. Ironically on newer manual shift 4wd systems the dash light is still triggered electrically by location of the shifter not what is going on in the transfer case (Ah a flaw in the design) So if you linkage is loose/bent/damaged or somehow disconnected your 4wd wont engage but the light will still show that it is! Hope this helps

Is the four wheel drive activated by vacuum? Check vacuum.

the code is the last 4 didgets of your chassis no

replace vacuum hoses they are located just out side shock towers front end

We unhooked the battery and left it unhooked all night. This morning when he reconnected it and started it, it started right up and the hold light and our check engine light went off. We did press the hold button and it came on and went back off when we hit it again.

That light sounds like a differential lock or 4-wheel drive. This is usually found in 4-wheel drive and all-wheel drive vehicles. Being the light is "GREEN" and not amber or red tells me that it's not an abnormal problem.

Look around your dashboard or gearshifter for a button labeled 4x4 HI, 4x4 LO, 4x2 HI. sport/off road button, or a second, smaller shifter. Switch them around a little, and if it is a 4x4 selector, be sure when you drive on paved roads to have it set to 4x2 HI. 4x4 HI should only be used if you get stuck to help you get out (snow/mud) and 4x4 LO is only for off road driving (trail blazing/rock climbing/4-wheeling/mud bogging,etc.)

Also, check for any switches labled "DIFF LOCK" or 'AXLE LOCK". In most cars a green light is normal operations.

I hope I could help you find a solution to your problem.