[RickNY]

While flipping through the manual, I came across information that I wasn't aware of.. My truck wont need a NYS Emissions test until 2012 -- but I noticed this warning in the Nissan manual:

Do not attempt to test a 4WD equipped vehicle on a 2-wheel dynamometer (such as the dynamometers used by some states for emissions testing), or similar equipment even if the other two wheels are raised off the ground. Make sure you inform test facility personnel that your vehicle is equipped with 4WD before it is placed on a dynamometer. Using the wrong test equipment may result in drivetrain damage or unexpected vehicle movement which could result in serious vehicle damage or personal injury.

New York State says that the dyno emission testing requirement is waived in the following conditions:

Vehicles that lack the ability to disable four-wheel drive, all-wheel drive, or traction control are exempt from the transient test (instead, the vehicle just gets an idle test)

Now.. I know VDC can be turned off, but that doesn't turn the ABLS system off.. But I was also reading that (if I am reading it correctly) ABLS is not active in 2H mode:

On 4WD models the ABLS system operates in both 4H and 4LO modes. If 4WD mode is engaged, the ABLS system will operate for both drive axles. On 2WD vehicles, the ABLS system operates on the drive axle only.

So here's my question.. I'm concerned that an inspection station may run the truck on the single axle dyno, despite Nissan's warning not to do so. Is this a real concern? What can happen? Obviously, I would likely ask the shop not to do it, and point out the section in the manual saying it can cause vehicle damage.. Has anyone had any real experience with this in New York or any other state that does two-wheel dyno emission tests?

Thanks,
Rick

 

[colin123]

Now.. I know VDC can be turned off, but that doesn't turn the ABLS system off.. But I was also reading that (if I am reading it correctly) ABLS is not active in 2H mode

ABLS is always on weather in 2wd or 4wd, but when in 4wd it also acts on the front wheels as well. i think what the problem is with being 4wd on these dynos is that we don't have manually lock/unlockable hubs so all of the drive line is always spinning when driving, and its designed to. now put your truck in a position where your rear tires are driving rather fast and the fluid in the transfer case is moving like crazy, while 4wd is not engaged i imagine this could cause the front drive line to want to move from the viscous momentum of the transfer case like how a tq converter works or the fact that the front drive line isn't moving may disrupt things in the transfer case. i would not let them put it on a 2wd dyno