I own a 98 GMC Jimmy 4X4, 4dr SUV SLT, automatic trans… this model has an electronic transfer switch on the dashboard to switch btwn 2W or 4W drive. the light on the switches indicates what drive your in. for past 6 mths the light on the 2HI has sometimes gone out, however if I push the button the light comes back on… I already had the fluid in the transfer case checked and it was fine, my owners manual indicate a dealer need to have it checked so I took it there today. I told them about the light going off… they told me it was the transfer case module- which was already replaced 2 years ago… so again I had it replaced today, however later that evening I noticed the 2 HI light went out again…obviously I will have to return to the dealer- but now I am wondering why they told me it was this module. Should not the diagnose that I paid for should have yielded the right cause?
So, just to be clear, is there anything wrong with the truck other than the light? I mean, if it’s not going into 4lo or 4hi and the truck’s still going, it must still be in 2hi, right? It sounds to me like there’s a loose connection in the light bulb in the 2hi button.
well… I have not attempted to put it in 4W option as it is not winter now… 2 yrs ago (in winter) I was in 4W and it wouldnt come out of it, I had to drive the vehicle slowly 10 mi to my mechanic to have him manually get it back to 2W, & then the dealer replaced this module- therefore trying to put the vehicle in 4W now could run a higher risk of transfer case damage if I got stuck in 4W again, I am assuming however that this dealer mechanic attempted to do so during diagnosing the trouble… since the owners manual specifically indicated that if the light goes out I should take it to the dealer I did… these past months however my gut kept telling me it was light related (bulb/sensor/fuse etc) and now that you mentioned it I am really wondering now…
The transfer case on my 2000 Blazer has trouble switching to 4wd if I don’t use it once every week or two. A GM Tech told me that the control module for the transfer case (located in the right kick panel) locks up (software?) and has to be reset by disconnecting it from the battery. Rather than removing the kick panel to unplug the module, I disconnect the battery to reset the module.
Note - this module is not the transfer case motor which is located on the transfer case. I engage 4wd every week or two for a short distance and this seems to keep the transfer case working properly.
Pry out the dash 4x4 switches and check the solder connections. Over time these can come loose. This MAY be the problem.