If you are saying BLD works only in 4 or 4lo, that's incorrect. It also works on the rear axle in 2wd.

 

This is my understanding too, although I have zero proof.

 

This isn't proof, but it is a chart showing the variuos modes of operation.

 

What is BAS and TCS? ERM? is one of them a BLD?

 

BAS (Brake Assist System)
The BAS is designed to optimize the vehicle’s braking
capability during emergency braking maneuvers. The
system detects an emergency braking situation by sensing
the rate and amount of brake application and then
applies optimum pressure to the brakes. This can help
reduce braking distances. The BAS complements the
anti-lock brake system (ABS). Applying the brakes very
quickly results in the best BAS assistance. To receive the
benefit of the system, you must apply continuous braking
pressure during the stopping sequence. Do not
reduce brake pedal pressure unless braking is no longer
desired. Once the brake pedal is released, the BAS is
deactivated.


ERM (Electronic Roll Mitigation)
This system anticipates the potential for wheel lift by
monitoring the driver’s steering wheel input and the
speed of the vehicle. When ERM determines that the rate
of change of the steering wheel angle and vehicles speed
are sufficient to potentially cause wheel lift, it applies the
appropriate brake and may reduce engine power to
lessen the chance that wheel lift will occur. ERM will only
intervene during very severe or evasive driving maneuvers.
ERM can only reduce the chance of wheel lift occurring
during severe or evasive driving maneuvers. It cannot
prevent wheel lift due to other factors such as road
conditions, leaving the roadway or striking objects or
other vehicles.

TCS (Traction Control System)
This system monitors the amount of wheel spin of each of
the driven wheels. If wheel spin is detected, brake
pressure is applied to the slipping wheel(s) to provide
enhanced acceleration and stability. A feature of the TCS
system functions similar to a limited slip differential and
controls the wheel spin across a driven axle. If one wheel
on a driven axle is spinning faster than the other, the
system will apply the brake of the spinning wheel. This
will allow more engine torque to be applied to the wheel
that is not spinning. This feature remains active even if
TCS and ESP are in either the “Partial Off” or “Full Off”
modes. Refer to “ESP (Electronic Stability Program)” in
this section.


TCS includes the Brake Lock Differential feature.

 

So, TCS = BLD. Just the name for the system.

 

TCS has other features, such as rolling back the throttle when the tires begin to spin. A good driver will do it, but most don't, so it's programmed in. When ESP/TCS is fully or partially disabled, throttle rollback will be disabled, but not the BLD feature.

 

Moral of the story, as I take it, is that LSD isn't worth the $ in a JK. not much on road performance increase, and locker is better off road. also it appears all clutch-based LSDs wear out quickly. truetrac would be the way to go if you get it done.

JK comes with TCS which works pretty well for slippery ice/snow/wet road.

 

If ya'll don't mind elaborating a bit more.
When I go play in the mud or sand, i hit the esp button, the jeep with the skid marks comes on on the display.
All four tires spin and sling mud and the jeep goes.

With the esp on , if the tires spin with the wheel turned it goes into limp mode.
I assume this is the safety built in the system.

2008 Wrangler X non rubicon.
So am I LSD or what?

 

Might have to check in with a dealership using your vin. that's how I found out. There is a way to check it by spinning one of your rear tires in the air. I personally think it's easier just calling a dealership lol.

Based on what you said I have zero clue. But ron might be able to weigh in.