Let's see if I can explain this without the manual because it can be confusing too.
VDC - Vehicle Dynamic Control
ABLS - Active Brake Limited Slip
VDC is looking at yaw sensors, wheel slip, steering wheel angle, throttle position and I'm sure a few more that I'm forgetting. An example of what VDC can do will probably mean more than the technical description of it.
Here's what it's capable of:
You get into a corner too hot and find your about to lose control of the truck, well VDC is way ahead of you in this example because the yaw sensors and steering wheel angle sensor has already noted that your in trouble. It will back off the throttle and brake each wheel independently to regain the composure of the truck. Now of course it's not going to defy physics and get you out of trouble irregardless of what you try, but it is watching and waiting to act.
If you tow, VDC is a VERY MUCH worthy option to have. Especially if you get fishtailing, it will do all it can to straighten you out so the shiny side stays up...
Go into an empty (preferrably wet to save your tires) parking lot sometime where you can play a little, get the truck going 35 to 40 (to play it safe) and start trying to toss it around. That's the best way to get a feel for what VDC is capable of.
ABLS is another cool program. It will brake each wheel independently to help regain traction and it has the ability to back off the throttle as well if a slip condition is detected. There are limitations to the ABLS, one big one is it needs front tire rotation in order to brake a spinning wheel in the rear. So another words if your doing smokey burnouts with the brake on, you'll typically only get one wheel to spin, but as soon as you let off the brakes, the ABLS will detect front tire rotation and speed, it will then brake the spinning wheel so both hook up.
If all of this sounds too confusing I can post what the service manual says, heck it will probably do a better job than I just did.
There is certainly more going on that what I just wrote, I just tried to simplify it the best I could.
There's one more mysterious function that the Titan has, and it leads me to believe it will be a while before anyone (aftermarket tuners) is able to crack the code. It's called NTD (Nissan Torque Demand). There's only a small paragraph on it in the service manual describing it, but it's actually the mother of all the limiters. NTD will actually vary the torque output on the Endurance engine based on Altitude/atmospheric pressure. Nissan added this mysterious overseer to help the Titan perform better in higher altitudes, which means........we aren't getting all we could at lower altitudes because NTD is spoiling our fun......How's that for a huge bummer!!!
Wow! I have to agree with Firecracker on that one! That was an outstanding explanation! It seems to me that the aftermarket tuner companies will have their work cut out for them. Do all Titans have ABLS? I know I have VDC (the button of course). What about NTD? All Titans have that I suppose. I tow a heavy trailer so I like that fact I have the VDC.
Am I right to assume that once aftermarket locking/limited slip rear differentials become available they may be useless in light of VDC and ABLS?
The manual is so vague on NTD that it's really hard to tell much about it. I assume they all have it because it's more for altitudes then anything else.
Am I right to assume that once aftermarket locking/limited slip rear differentials become available they may be useless in light of VDC and ABLS?
I really don't know the answer to that one just yet. I believe Nissan confused things a lot when they offered the E-lock option but said it wasn't compatible with VDC. hmmmmm, that I doubt is really the case. It appears they had no intention of even using e-lock unless your in 4lo, at which time VDC shuts off too. So I'm a little skeptical on their explanation on that one. Also I don't see how a true LS diff would have a negative impact on the operation of VDC or ABLS. Heck in reality it would make ABLS work less....The true answer remains to be seen as to what the aftermarket offers for which options Nissan has used.
Let me say one more thing concerning NTD. Think about the possibilites this program has in it and the untapped potential. If this engine will make more hp to compensate for higher altitudes, then at lower atltitudes it means it's derated. In other words if an aftermarket tuner, such as hypertech or Jetchips can come up with a way to fool this sensor into thinking your at an extremely high altitude, then guess what???? Mucho more power with no additional mods. That's why I'm holding out for a program/tuner that will let us take advantage of the untapped potential this engine and ECU obviously has. Neat stuff ain't it??
Too bad I can't find anything in the service manual as far as the wiring goes to the NTD program, wouldn't an inline resistor be a nice mod...
now im going to go crazy knowing there is corked up power in the motor because of the damn ECU. almost wish i didnt read that part :lol: .....well mabye not.
The wiring diagram in the service manual makes no mention of it, just the temp sensor. I've been home today taking care of my wife, she had minor surgery this morning, and I'll probably be home tomorrow doing the same thing so I'll keep checking.
well best wishes to your wife and good luck tomarrow. if the service manual has no mention of it in the wiring diagram its hidden. it could be anywhere on truck, mabye behind the dash somewhere not easily accesable.
what altitude are you at JT? my gps says im at 810 feet, im getting screwed to the max on this.
I'm starting to think the MAFS is somehow calculating the altitude and then sending it to the ECM because I just looked at every wire input into the ECM and not one made any reference to an altitude sensor. I'll have to do some reading on the net and see if the MAFS is able to do this.
i noticed that there are 5 or 6 wires into the MAFS, what else could be in there beside MAF and IAT sensors? that meens there are a couple extra wires in there. what are they for?
i noticed that there are 5 or 6 wires into the MAFS, what else could be in there beside MAF and IAT sensors? that meens there are a couple extra wires in there. what are they for?
I keep coming up with nothing on this topic of NTD. There is a picture in the manual that shows all the inputs to the NTD section of the ECU. Not one is in any way related to atmospheric pressure. I'm stumped. Maybe next week I'll stop in and see my Nissan tech buddy and see if he knows. I'll make sure to let you know what I find out.
Thanks guys...this is a very enlightening and interesting post, I hope you pursue it. The aftermarket had a hard time cracking the ECU on the Hemi...and that's all they did. They didn't open it. Nissan's appears to be even more elaborate and complex.
Anyway, this dumb ol' country boy applauds your efforts...and your sharing . BTW BiXLL, watch the head, they're right! :wink:
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