Question on 01 Bravada NV136 trigger
 

I may have missed this in my search, but on my 01 Bravda, what triggers the NV136 case to transfer power to the front wheels. I know it detects wheel slippage but is that through the antilock brake system or another system that detects the whee slippage?

The reason I ask is I'm starting to deal with a rather annoying ABS light going on and off and want to ensure that as the winter creeps up that I will still have my AWD.

The NV136, NV236, and the ABS, all share wheel and vehicle speed sensor data. If there is a problem with any of the 3 sensors, none of the systems will work. If/when a problem is detected with any of the sensors, the EBCM will set a DTC in memory and illuminate the ABS light. You will need a scan tool capable of accessing the ABS to retrieve the DTC and diagnose the problem.

Thanks, I'm sure the abs issue is part of the passenger side wheel bearing which is making noise. I'm getting it fixed here soon but didn't know where the AWD pulled its data from.

Thanks!

It's doing the low speed ABS chatter I've read about and the ABS light is going on briefly, generally at a stop and then going off when I start. With the wheel bearing noise starting I'm pretty confident that's the issue.

Low speed activation that the TSB covers, (rust behind sensor) does not turn the light on. Might want to get the codes retrieved.

Thanks for the heads up....was unaware of that. What's funny is its on for 20-30 seconds sometimes at a stop and then goes out. I'll get the codes read.

If the light is coming on, there might be a poor connection, (broken or breaking wire, etc) at or near a front wheel speed sensor. The codes will tell what circuit is experiencing a malfunction. Keep in mind that DTC's never tell you to replace a part, they tell you what circuit was or is out of range.

Just to close down this thread, but I got the wheel bearing replaced and now my ABS issue (chattering and random ABS light at some stops and turns) is totally gone. I did check out the old bearing and sensor but didn't see anything like a broken wire, but it could have been in the wrapped area or something I didn't see.

In any case, resolved!!!!