differential / VSC problem (1 Viewer)

[kgrove]

Today I get in my car (2007 LC) and backup and it feels like the wheels get stuck on something, so I pull forward... takes me a couple of tries to make it out of my parking spot. Finally, I notice the differential is locked and the VSC light is on. I pushed the diff lock button to disengage, but it doesn't work. I try it in neutral, in park, in drive and moving slowly forward. I shut the car down and restart. I try all those again. Nothing - differential is still locked. I'm only a few miles from home so I figure I'll nurse the car back home and figure things out. On the drive home, suddenly the differential unlocks. So the questions:

1) I really don't think I accidentally hit the differential lock button. Are there any other ways the differential could have locked without me hitting the button somehow?
2) Does the differential have some kind of speed activated disengaging mechanism that caused it to unlock when I got to regular road speed (maybe 45 mph)?
3) I just had my differential and transfer cases drained and re-lubed a few months ago. Ccould there be a link between a recent differential oil change and a "self-locking" issue?
4) Should I be overly concerned on this first appearance of a ghost in the machine? I'm hesitant to drag it in for repairs until I know for sure that I didn't unknowingly bump the button, but I might deal with the inconvenience if I thought the risk of ignoring a potential problem was a major breakdown. What if any simple tests could I try to test the differential locking mechanism?

 

[n55luvr]

I accidentally hit my CDL button with my knee on occasion. Horrible spot for that button IMHO.

I also do not believe there is any auto unlock at a certain speed. Regarding the drain and refill, I suppose if they used the complete wrong lube it might cause an issue but unlikely.

I have also had my CDL engage and not want to disengage, this was when I first bought it and suspect it hadn't been engaged in years. Took me going in reverse, cranking the wheel full lock and slowly adding gas. Tried all the normal stuff first, this approach was last resort. Took one little chirp of the front wheels and CDL disengaged. I now hit the CDL button once a month or so and it locks in and out instantly, no issues.

 

[Sandroad]

I'll bet you simply hit the button with your knee and the drivetrain bound up a bit so it took some driving to get it to unlock. It can't lock by itself and there is no speed-related unlocking. The "ghost" was likely just your errant knee.

 

[kgrove]

I'll bet you simply hit the button with your knee and the drivetrain bound up a bit so it took some driving to get it to unlock. It can't lock by itself and there is no speed-related unlocking. The "ghost" was likely just your errant knee.

I suspect you're right. I've driven it a number of times since and everything appears fine. I really didn't think I bumped the switch, but maybe I did. I'll experiment over the next week or two and lock the diff on purpose a few times to see if it disengages better. Maybe it wouldn't disengage because it hadn't been used in quite some time.