Question about traction control

[Renegade]

BLD and Traction Control are pretty much the same thing. The system modulates the brakes of a spinning wheel to send torque to the wheel with the traction. I believe a situation could exist, especially if climbing a steep off road grade, that the result would feel like power is being cut. I have experienced this as well, in a JK and the JT, and chalked it up to the system doing its thing. I do agree that it could be better if it allowed appropriate wheel spin to maintain RPMs/power.

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[ShadowsPapa]

BLD and Traction Control are pretty much the same thing. The system modulates the brakes of a spinning wheel to send torque to the wheel with the traction. I believe a situation could exist, especially if climbing a steep off road grade, that the result would feel like power is being cut. I have experienced this as well, in a JK and the JT, and chalked it up to the system doing its thing. I do agree that it could be better if it allowed appropriate wheel spin to maintain RPMs/power.

Although BLD is part of traction control, it only operates in 4L or 4H and cannot be turned off even if TC is disabled.

I've never seen it behave like his does.

 

[CarolinaGladiator]

BLD and Traction Control are pretty much the same thing. The system modulates the brakes of a spinning wheel to send torque to the wheel with the traction. I believe a situation could exist, especially if climbing a steep off road grade, that the result would feel like power is being cut. I have experienced this as well, in a JK and the JT, and chalked it up to the system doing its thing. I do agree that it could be better if it allowed appropriate wheel spin to maintain RPMs/power.

This is partially true. BLD works with the TC but also will work with the TC off. At least that's the way it's explained everywhere I can find info on it. It should NOT be killing the engine power but instead transferring that power to the wheels with traction while also applying brake to the wheel with less traction.

When you shift to 4L the computer turns off TC and ESC. The BLD (if it's still active and I believe it should be) should have no effect on the engine RPMs.

 

[CarolinaGladiator]

I will be at Uwharrie this weekend and I'll try to replicate it but not sure I'll be able to.

 

[hjdca]

Does "Off Road Plus" on the Rubicon disable it ? I took mine wheeling a few times and in - first gear 4W high, with the traction control off, "Off Road Plus" on --- I could do donuts in the dirt with tons of wheel spin --- but, my Gladiator Rubicon is a manual.

 

[MarineHawk]

... The TC was off (at least the light said it was) so I don't understand why I couldn't get the RPMs up and hold them there. … This really felt like the TC kicking in and killing the power to the wheels. The JT automatically turns off the TC and stability control when the transfer case goes into 4L and the light was on confirming the TC was off. Is there something I'm overlooking?

… even if TC is disabled.

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The off switch showing the swerving vehicle image is the off switch for the ESC (Electronic Stability Control) system. See 2020 Gladiator Manual at p. 76,

There apparently is no way to completely turn off the TC system, which is separate and which “monitors the amount of wheel spin of each of the driven wheels. If wheel spin is detected, the TCS may apply brake pressure to the spinning wheel(s) and/or reduce engine power to provide enhanced acceleration and stability. A feature of the TCS, Brake Limited Differential (BLD), 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. BLD may remain enabled even if TCS and ESC are in a reduced mode.”

 

[CarolinaGladiator]

Yep, no button for TC. The problem with that is that when you go into 4L the computer turns off the ESC and the TC. It comes up on the dash and lets you know. It literally reads "Traction Controls system is Off" right on the dash cluster. The BLD is still active but the BLD alone should not cut power to the engine, only apply braking power to one wheel across each axle. I don't claim to know exactly how it works but I can read and comprehend the words that are printed on the instructions. Now if they can't print clear instructions then that's not my fault. Contrary to my wife's beliefs, I'm not a mind reader.

If the TC isn't off, the truck shouldn't tell me it is. "Off" and "Reduced" mean different things and they should be used accordingly.

 

[ShadowsPapa]

Bottom line is you cannot disable BLD. That's according to Jeep.
You must have married my wife's sister. My wife keeps insisting I know what she's talking about......

 

[CarolinaGladiator]

I know the BLD is always active. I just don't think that's what it was. It felt like the TC kicking in.

 

[hjdca]

I do not think BLD is active on the manual transmission (3 pedal) when you select traction control off and off-road plus. At least I have not felt it at all. I could spin the tires all day long in the sand in this mode. Maybe with the clutch architecture, Jeep completely disables the brake application of BLD to make sure the system does not stall the car with the clutch out. I know I can crawl in both 4WH and 4WH with the clutch out and plenty of wheel spin and nothing is applying brakes on the drivetrain.

 

[ShadowsPapa]

I know the BLD is always active. I just don't think that's what it was. It felt like the TC kicking in.

Yes, your description matches almost exactly how my Silverado did when I tried to fly around corners and spin a wheel - the engine actually felt like it had run low on fuel or was lean - like I'd let off or something. Even trying hard to mash it to get across a busy highway - forget it, you'd be dead. Your JT sounds like my Chevy did. IT does not sound at all like BLD - not in the slightest, at least to me.
You could lock all brakes and it shouldn't sound like the engine was slowed down - just sound like it was under load.

 

[MarineHawk]

... It felt like the TC kicking in.

Nothing is certain, but I am thinking the same thing. I assume the possibility of this can be preempted in the Rubis by locking the axle. Otherwise, I wonder if the Jeep TC works like the Hummers I mentioned above. Any pressure on the brake and the TCS completely went off. That's one reason why we used the BTM method a lot in 4WL. It also work well on rocks. You don't have to gun the engine to get a tire up a big rock. You just keep the RPMs constant at about 1,700 and slowly let off the brake with your left foot until it slowly goes up the rock.

 

[ShadowsPapa]

Batter if you don't gun it. Like a couple of truck drivers told me about slippery surfaces - keep it in as high a gear as you can without lugging as too much engine power will simply break the wheel loose and you spin. That of course was for manual transmission trucks - like delivery trucks...... bigger than UPS or Fedex, but still not semi tractor and trailer.

 

[CarolinaGladiator]

This bugs me. I will try and recreate the problem this weekend. If I can get it on video I will post it for all to see exactly what's going on.

 

[MarineHawk]

This bugs me. I will try and recreate the problem this weekend. If I can get it on video I will post it for all to see exactly what's going on.

Many thanks in advance. That would be helpful to us all going forward.

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