2017 Transfer case knob - lights not working

[BostonMike]

I'm looking to buy a 2017 Tahoe. When starting the truck, the indicator light on the 'transfer case knob' lights up next to 'Auto'. But when switching the knob between 2WD / Auto / 4WD, the dashboard briefly displays a message that the shift is occurring, and I hear something happening, but the knob then has no illuminated indicator lights. The knob remains dark after repeatedly changing the transfer case mode.
Is this a known failure mode? Is it likely just a faulty knob assembly? Or does it tend to be an issue with the transfer case?

Thanks!

 

[Tahoe14]

@NickTransmissions may be able to help

 

[NickTransmissions]

Sorry, im not familiar with those T cases but it sounds like sensor or switch issue to me.

Plug in a scan tool capable of reading chassis codes to see what, if anything, shows up.

 

[Tahoe14]

@swathdiver, do you know someone on the board that may have knowledge of this

 

[swathdiver]

I'm looking to buy a 2017 Tahoe. When starting the truck, the indicator light on the 'transfer case knob' lights up next to 'Auto'. But when switching the knob between 2WD / Auto / 4WD, the dashboard briefly displays a message that the shift is occurring, and I hear something happening, but the knob then has no illuminated indicator lights. The knob remains dark after repeatedly changing the transfer case mode.
Is this a known failure mode? Is it likely just a faulty knob assembly? Or does it tend to be an issue with the transfer case?

Thanks!

Mike, did the mode change actually occur? If you switch into 4HI, is it in 4HI? It could be that the lights in the knob are burnt out or there could be something wrong preventing the shift from occurring.

When people leave the transfer case in Auto mode all the time, the life of the unit is reduced greatly.

 

[Tahoe14]

@BostonMike, trying to get you some help.

 

[BostonMike]

Mike, did the mode change actually occur? If you switch into 4HI, is it in 4HI? It could be that the lights in the knob are burnt out or there could be something wrong preventing the shift from occurring.

When people leave the transfer case in Auto mode all the time, the life of the unit is reduced greatly.

It was hard to tell without punching it and checking for wheel spin
The dash messaging says it is changing mode, but nothing after that. No error messages though.

Update: I had the dealer I was buying it from replace the switch and the indicator lights are all working perfectly now.

Question about your comment above: The Tahoe owners manual says leaving it in 'Auto' will engage the front axle only when needed and slightly reduce milage. Are you suggesting that Auto also adds significant wear to the drivetrain?

Thanks

 

[BostonMike]

Thank you everyone for your replies. I had the dealership I was buying it from diagnose and then replace the switch assy. The indicator lights work perfectly now. I had asked the question ahead of time just to see if the switch lights 'dying' was a common occurrence vs. an issue with the transfer case. If these switches die periodically, then I'd feel much more comfortable that a new switch is the problem.

 

[swathdiver]

Question about your comment above: The Tahoe owners manual says leaving it in 'Auto' will engage the front axle only when needed and slightly reduce milage. Are you suggesting that Auto also adds significant wear to the drivetrain?

Over time, yes.