The service 4wd light has been on since I bought the truck, I had an ABS light and when scanned it came back as a bad front right and rear left wheel speed sensors but there is no rear left wheel speed sensor. So what do I need to replace? And could that be the reason that the all-wheel drive is not working? I appreciate any help on this as finding threads on bravadas are few and far between, most of what I see says to check the encoder motor or the tccm but I figured the ABS light could be causing the truck to not know when the rear wheels begin to lose traction and to engage the front axle

 

When I turn the steering wheel a little bit it's fine but when I have to make a sharper turn or a U-turn or something the front end starts to bind up and almost feels like when a truck is in four-wheel drive it almost hops a little bit. If I'm going really slow it will make the truck come to a stop and it struggles to make the turn, any idea what could be causing this? Thanks

 

I am not at all familiar with Bravadas, sorry, but there are many members on here who are very knowledgeable on everything you will need too get your problems fixed. I am sure you will get some helpful responses soon, good luck.

 

I have merged your two threads discussing the awd issues with your truck as they are very likely to be related to the same problem.

First thing I will mention is that the NV136 transfer case used in the later s-series Bravada was very sensitive to fluid type & quality. AutoTrak II fluid from GM needs to be used. I would recommend that you drain the transfer case and refill it if you have never done so. It takes just shy of 2qts to fill a drained t-case. If the old fluid comes out very dirty looking or is red, that could mean problems. While the original AutoTrak fluid was red in color, so was every other ATF available and ATF does not have the proper friction modifiers in it for the viscous coupling used in these t-cases. If regular ATF was used, it can cause the viscous coupling to lock up. If this has happened, it may take a few t-case fluid changes to remedy the issue.

You are correct in that there are no sensors on the rear axle to differentiate left/right. There are three different speed sensors on the transfer case that are used for various purposes. The ABS system uses the VSS (vehicle speed sensor) at the back of the t-case along with the two speed sensors at each front wheel hub. The TCCM uses the other two speed sensors (front/rear output speed sensors) in the transfer case along with those used by the ABS system to detect slip & correctly engage the t-case. Beyond that, we really need the specific trouble code you pulled from the ABS to help further.