How Does VTM Work? - Honda Pilot - Honda Pilot Forums

Register Home Forums Active Topics Insurance Photo Gallery Garage Search Today's Posts Mark Forums Read Auto Escrow
Piloteers.org is the premier Honda Pilot Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Rate Thread
Old 01-05-2009, 12:50 AM   #1 (permalink)
Member

 
Alpo714's Avatar
 
Join Date: Nov 2008
Location: Fullerton, California
Posts: 32
Feedback Score: 0 reviews
Send a message via AIM to Alpo714
Default How Does VTM Work?

As stated in the subject header, How does VTM work exactly? I have a 2004 Pilot EX with Navi and I am fascinated about what VTM does and how it contributes to the pilot being a great light-off-roading vehicle. Also I am not too sure how the 4WD works.

From my understanding, pilot primarily front wheel drive until it detects slippage on the front tires. When it detects slippage on the front tires, the transmission then diverts torque to the rear tires.

Please, clarify how VTM operates in relation to the 4WD system of a 2004 Pilot.
__________________
2004 Honda Pilot 4WD EX-L w/ Navigation
Alpo714 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-05-2009, 12:58 AM   #2 (permalink)
Super Moderator
 
humanoid's Avatar
 
Join Date: Sep 2004
Location: Sunny SoCal
Posts: 3,748
Feedback Score: 0 reviews
Send a message via Yahoo to humanoid
Default

The VTM system is the 4wd system.
__________________
<------------ click here first, n0oB!!!
humanoid is offline   Reply With Quote
Old 01-05-2009, 01:54 AM   #3 (permalink)
xGS
Registered User
 
xGS's Avatar
 
Join Date: Oct 2003
Posts: 2,532
Feedback Score: 0 reviews
Default Re: How Does VTM Work?

Quote:
Originally posted by Alpo714

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.
xGS is offline   Reply With Quote
Old 01-05-2009, 02:44 AM   #4 (permalink)
Member

 
Alpo714's Avatar
 
Join Date: Nov 2008
Location: Fullerton, California
Posts: 32
Feedback Score: 0 reviews
Send a message via AIM to Alpo714
Default Re: Re: How Does VTM Work?

Quote:
Originally posted by xGS


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!
__________________
2004 Honda Pilot 4WD EX-L w/ Navigation
Alpo714 is offline   Reply With Quote
Old 01-05-2009, 08:50 PM   #5 (permalink)
Member

 
Join Date: Apr 2005
Location: Connecticut
Posts: 46
Feedback Score: 0 reviews
Default

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.
__________________
05' Pilot EX-L Steel Blue [mods: Honda rear mud guards, Curt hitch]
04 Audi A4 3.0 6MT
mriley is offline   Reply With Quote
Old 01-05-2009, 10:44 PM   #6 (permalink)
Registered User
 
rlapid's Avatar
 
Join Date: Sep 2006
Location: West Sacramento, California
Posts: 847
Feedback Score: 0 reviews
Default

Quote:
Originally posted by mriley
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.
__________________
2006 Pilot EX-LN 4WD | Taffeta White | "Amelia"

OEM accessories: chrome side steps, crossbars, cargo tray, cargo cover, wheel locks, rear splash guards, door edge guards, full-size spare

Aftermarket accessories: Yakima Big Powderhound, LED license plate and door bulbs, Infinity 6012i speakers, 4300k HID, 35% tint, Nokya yellow fogs + yellow Lamin-X
rlapid is offline   Reply With Quote
Old 01-06-2009, 06:17 PM   #7 (permalink)
Wook #17
 
PhishingPhreak's Avatar
 
Join Date: Dec 2005
Location: The South Shore, St. Louis
Posts: 77
Feedback Score: 0 reviews
Default Re: Re: How Does VTM Work?

Quote:
Originally posted by xGS


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?
__________________
"This is going to be a very expensive war, and Victory is not guaranteed -- for anyone, and certainly not for anyone as baffled as George W. Bush. All he knows is that his father started the war a long time ago, and that he, the goofy child-President, has been chosen by Fate and the global Oil industry to finish it Now."

Dr. Gonzo
PhishingPhreak is offline   Reply With Quote
Old 01-06-2009, 06:27 PM   #8 (permalink)
Registered User
 
RSQ Pilot's Avatar
 
Join Date: Aug 2008
Location: Central IL & Many Road Trips
Posts: 1,798
Garage
Feedback Score: 0 reviews
Default

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
__________________
2009 Pilot Touring RES 4wd Mocha Metallic; OEM Premium Running Boards, OEM cargo tray, Weathertech Floor Liners, H-9 LB mod, full size LTX spare w/alloy rim, AVS Bugflector II
2010 Honda CR-V EX-L AWD Taffeta White...OEM cargo tray, mudguards and WeathertTech floor liners; Blue Ox dinghy setup.
2007 Winne Aspect 26A; Ford V10 gas hog, Blue Ox dinghy setup.
RSQ Pilot is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 03:03 AM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.3.2
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
Copyright 2000 piloteers.org. All Rights Reserved.