The VTM system is the 4wd system.

 

Wow, thank you captain obvious!

 

How does VTM work exactly?

VTM-4 Engagement Modes

There are three distinct modes of VTM-4 engagement:

(1) The first mode, called Acceleration Torque Control (ATC), works whenever the vehicle's throttle is depressed, even on dry pavement - a feature unique to the VTM-4 system. Sensors in the engine and transmission monitor vehicle speed and acceleration. The amount of torque applied, as directed by the system's ECU, is determined according to vehicle speed, the amount of acceleration and transmission status (gear setting). This benefits not only the Pilot's ability to gain traction from a standing start, before wheel slip occurs, but also its overall dynamic stability on both dry and slippery roads. Reducing the propulsive force carried by the front tires under acceleration reduced torque steer and cornering adhesion. Rear wheel torque rises smoothly from zero to a preset maximum in proportion to vehicle acceleration (both forward and reverse). During constant-speed driving, all power is driven to the front wheels for improved fuel efficiency.

(2) The second engagement mode occurs when wheel slip is detected. Differences in rotational speed between front and rear wheels are measured by sensors in the ABS system and monitored by the ECU. In response, the ECU commands an increase in torque delivery to the rear wheels. Torque application is adjusted according to the amount and the rate of change in wheel slip. As slip increase, more power is delivered to the rear wheels for improved traction.

(3) The third mode of engagement is VTM-4 Lock. Lock mode occurs when the driver shifts into first, second or reverse gears and depresses the VTM-Lock button on the instrument panel. When lock mode is selected at vehicle speeds below 18-mph, the system ECU commands a preset maximum amount of rear-drive torque to be delivered to the rear wheels for improved traction in very low-speed, low-traction, conditions. As control is regained and vehicle speed increases, the system gradually reduces rear axle torque until it is completely disengaged.

 

Perfectly explained here. I would only add that for situation #3, disabling VSA (by pressing its button) improves traction even more, if you're really stuck.

 

Re: Re: How Does VTM Work?

VTM-4 Engagement Modes

There are three distinct modes of VTM-4 engagement:

(1) The first mode, called Acceleration Torque Control (ATC), works whenever the vehicle's throttle is depressed, even on dry pavement - a feature unique to the VTM-4 system. Sensors in the engine and transmission monitor vehicle speed and acceleration. The amount of torque applied, as directed by the system's ECU, is determined according to vehicle speed, the amount of acceleration and transmission status (gear setting). This benefits not only the Pilot's ability to gain traction from a standing start, before wheel slip occurs, but also its overall dynamic stability on both dry and slippery roads. Reducing the propulsive force carried by the front tires under acceleration reduced torque steer and cornering adhesion. Rear wheel torque rises smoothly from zero to a preset maximum in proportion to vehicle acceleration (both forward and reverse). During constant-speed driving, all power is driven to the front wheels for improved fuel efficiency.

(2) The second engagement mode occurs when wheel slip is detected. Differences in rotational speed between front and rear wheels are measured by sensors in the ABS system and monitored by the ECU. In response, the ECU commands an increase in torque delivery to the rear wheels. Torque application is adjusted according to the amount and the rate of change in wheel slip. As slip increase, more power is delivered to the rear wheels for improved traction.

(3) The third mode of engagement is VTM-4 Lock. Lock mode occurs when the driver shifts into first, second or reverse gears and depresses the VTM-Lock button on the instrument panel. When lock mode is selected at vehicle speeds below 18-mph, the system ECU commands a preset maximum amount of rear-drive torque to be delivered to the rear wheels for improved traction in very low-speed, low-traction, conditions. As control is regained and vehicle speed increases, the system gradually reduces rear axle torque until it is completely disengaged.

Wow. That is an incredibly detailed response. Thanks xGS!

 

Question

In the second engagement mode, I have noticed a slight, momentary drag. Is the ABS engaging to help correct the slippage?

I ask because during some recent storms in the Northeast, on a slippery hill, I can feel one or more wheels slipping, then a mometary drag, like someone is touching the brakes and then the vehicle surges with what feels like four wheel drive. It then powers forward, starts to slip, slight drag and the takes off again. This will continue if I'm too aggressive for the driving conditions.


And by the way, I have new Michellin M+S tires.

 

Question

In the second engagement mode, I have noticed a slight, momentary drag. Is the ABS engaging to help correct the slippage?

I ask because during some recent storms in the Northeast, on a slippery hill, I can feel one or more wheels slipping, then a mometary drag, like someone is touching the brakes and then the vehicle surges with what feels like four wheel drive. It then powers forward, starts to slip, slight drag and the takes off again. This will continue if I'm too aggressive for the driving conditions.


And by the way, I have new Michellin M+S tires.

If you are in deep snow,sand, or other turn the traction control off (VSA) so the ABS does not hinder wheel spin. I have an 04 Pilot and Honda did not add trac control until 05 thank goodness, I hate it and was turning it off all the time in my prev accord

 

In the second engagement mode, I have noticed a slight, momentary drag. Is the ABS engaging to help correct the slippage?

i believe that's the VSA (traction control) kicking in. i've experienced the same drag or hesitation upon hard acceleration on icy/wet pavement, accompanied by the flashing VSA symbol in the instrument cluster.

 

Re: Re: How Does VTM Work?

VTM-4 Engagement Modes

There are three distinct modes of VTM-4 engagement:

(1) The first mode, called Acceleration Torque Control (ATC), works whenever the vehicle's throttle is depressed, even on dry pavement - a feature unique to the VTM-4 system. Sensors in the engine and transmission monitor vehicle speed and acceleration. The amount of torque applied, as directed by the system's ECU, is determined according to vehicle speed, the amount of acceleration and transmission status (gear setting). This benefits not only the Pilot's ability to gain traction from a standing start, before wheel slip occurs, but also its overall dynamic stability on both dry and slippery roads. Reducing the propulsive force carried by the front tires under acceleration reduced torque steer and cornering adhesion. Rear wheel torque rises smoothly from zero to a preset maximum in proportion to vehicle acceleration (both forward and reverse). During constant-speed driving, all power is driven to the front wheels for improved fuel efficiency.

(2) The second engagement mode occurs when wheel slip is detected. Differences in rotational speed between front and rear wheels are measured by sensors in the ABS system and monitored by the ECU. In response, the ECU commands an increase in torque delivery to the rear wheels. Torque application is adjusted according to the amount and the rate of change in wheel slip. As slip increase, more power is delivered to the rear wheels for improved traction.

(3) The third mode of engagement is VTM-4 Lock. Lock mode occurs when the driver shifts into first, second or reverse gears and depresses the VTM-Lock button on the instrument panel. When lock mode is selected at vehicle speeds below 18-mph, the system ECU commands a preset maximum amount of rear-drive torque to be delivered to the rear wheels for improved traction in very low-speed, low-traction, conditions. As control is regained and vehicle speed increases, the system gradually reduces rear axle torque until it is completely disengaged.

What does ECU stand for?

 

ECU/ECM=the BRAINS of the operation=electronic control unit/module

http://en.wikipedia.org/wiki/Engine_Control_Module

http://en.wikipedia.org/wiki/Electronic_control_unit

 

i have a 2004 honda pilot, not sure the trim level
it has the vtm 4 lock button
does this mean it has the 4wd auto aspect?
can a pilot be a fwd with a vtm 4lock only? meaning it isnt 4wd beyond low gear/get unstuck mode?

 

Your 2004 is front wheel drive and the VTM-4 automatically activates when needed. You can also manually activate VTM-4 mode as well. XGS in one of the posts above has a great explanation of how it works.

 

So it is 4wd that activates as needed, just in my experience it’s hard to tell or know it’s activated, I do a lot of winter and snow driving

 

The Pilot's AWD/VTM-4 system was originally introduced on the MDX and was designed, as Honda then described it, to "defeat winter" - as opposed to climb rocks.
However, the performance of the system will only be as good as the grip of your tires allows it to be.
What tires are you using?

 

That what makes the system great, turns on when needed and you don't even know that it turned on.

 

So is the VTM better than having all wheel drive like the newer models have?

 

Isn’t VTM just the type of AWD system that is used in Pilots (new or old).

 

...And clearance. The only thing that (nearly) defeated my Pilot's VTM-4 and Nokian Hakkapeliitta R2s last winter was bottoming out.

https://www.piloteers.org/threads/h...how-does-pilot-with-stock-tires-handle-rain-and-snow.118361/page-3#post-1588251

 

That "bottoming out" phenomenon is what I refer to as 'tobogganing'.

 

I concur with the VSA off if off road, getting out of deep snow etc. I had it on my FWD CRV and it sucked! my TPMS went wonky and then the VSA off button wouldn't work. I had to put a switch on the VSA fuse for getting up my driveway in winter because if your TPMS is broke you can't turn of the VSA and if your wheels spin even a little it cuts engine power. Not the best thing for a vehicle that has to drive in a Canadian winter and is only FWD. So far the 11 Pilot EX 4WD with X-Ice Michelins has gone through anything I needed it too. Driveway with 24" of snow, slow down, drop to 2nd, push VTM-4 Lock, push and HOLD VSA until it beeps and then give her the beans and up the 35 deg grade of drive and into the garage she goes. I will say that the VSA is nice when at speed and roads get iffy, it kicks in and tells you to slow down, or at least if I'm doing the speed limit and it kicks in on the back roads I know to slow down because something was slippery. But at slow speeds trying to get through deep snow it just frustrates the heck out of you and I am glad you can shut it off in those situations.

 

You, sir, understand how to make VTM-4 and VSA work best for you in snow and ice. Not everyone does.

 

I'm glad with this generation of Pilot the TPMS can recognize more than 4 sensors. our 2010 CRV when I swapped to the winter wheels and tires it wouldn't recognize them and shut off, I would have had to pay the dealer $75 to reprogram the TPMS in the winter, then in the spring everytime I changed tires. I got second set of wheels for a reason, So when the tires wore, I switched the winter tires to the wheels that were programed and we could shut VSA off, that lasted one winter until we Hit a pothole and broke a sensor, after that I just put a switch on the dash that basically pulled the fuse so VSA, ABS and all the nanny aids shut off. you could then spin the tires enough to get up the drive, flick it back and everything went back on. I was pleasantly surprised when I put the winter tires and wheels on that came with the Pilot that the TPMS trouble light stayed off. I got Brand new Michelin X-Ice tires on steel honda wheels with it. That made the price much more attractive.