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I have a Honda Pilot 2008 and using it to pull a tent trailer. The trailer is 2200Lb and is within specs for the Pilot. This is a variable 4 wheel drive transmision, this means I can change the amount of power that goes to the front or rear tires. Typically the Pilot runs with 60% to the front and 40% to the rear. There is a button I can press while on first or second gear (or reverse) which is called VTM-4 which locks the Variable Torque to 50%-50%.

The problem: I use it to climb a hill to get to my piece of land. The road is quite steep and rocky. Whether I use VTM-4 lock or not the results are the same. During the ascent, the alert indicator (exclamation mark) lights up and at the same time the transmision stops giving power to the wheels. This last for a second or 2, then the traction comes back and the light goes off. During the ascent, the light goes on and off a couple of times while the traction does the same thing. When I reach my destination, there is a burned or smoke smell.

It is quite enervating as you are on a steep hill climbing with a 2200Lb trailer in the back and traction stops...

Maybe the Honda Pilot is not made to be used in those conditions. If that is the case, which car/suv would be my best option? I was looking at the Grand Cherokke but it seems to have a similar 4wd transmission.

  • Could this be the traction control? You could try turning it off. – Nate Eldredge Dec 10 '14 at 15:07
  • Can you deactivate the traction control? My guess is the TC detect some wheel spinning and take control. – Gabriel Mongeon Dec 10 '14 at 18:14
  • There is no spinning on none of the wheels. It goes perfectly well until the traction is turned off by the computer, which was probably triggered by a heat sensor located in the 4wd differential. It heat because it is a slip glutch that is managing the torque which is bad in my case. It should be a locked mechanically differential like on the Jeep wrangler for example. I am just looking for other options, other than the Wrangler that I find too small storage wise. Jeep Liberty worst... what else have a lockable differential? – Guillaume Bois Dec 10 '14 at 20:11
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While this is not "scientific data", I did find some empirical data on the subject from this website. The author talks about his experience with the Honda Pilot and its VTM-4 system:

Reading about VTM-4, the way I understood it to work was this...

Under normal conditions, the VTM-4 system is FWD biased and transfers power/torque to the rear as needed. If you need extra traction then engaging VTM-4 Lock would lock the rear differential and send power to both rear wheels.

What I experienced today was quite different. I found a nice little hill with some sections that would get a vehicle crossed up (For anyone that doesn't know, getting crossed up basically means a pair of tires at opposite diagonal corners are compressed and firmly on the ground while the other pair of tires are drooped and possibly not even touching the ground. An open 4WD/AWD system would simply end up spinning the two wheels with the least traction and you'd go nowhere.

So, what happened? I started out with the system on full auto and started up, didn't make it too far. Hit VTM-4 Lock and only made it a couple more feet. I had my wife watch what the wheels were doing...

Full Auto/No Lock - Only the front tire would spin, nothing going on in the rear.

VTM-4 Lock - The front tire at full droop and the rear tire at full droop would spin. The rear tire firmly planted on the ground did nothing and there was no forward progress. Turned off VTM-4 Lock, back to only the front wheel spinning.

Doing some reading, it sounds like the rear "lock" isn't a true mechanical lock but more like an aggressive limited-slip with clutches. That being the case, this situation and the results sort of make sense and I was likely just overpowering the "locked" clutches in the rear, however I was surprised that the rear tire wasn't spinning at all when in full-auto. What it ultimately felt like was that there's a center differential with clutches, splitting power between the front and rear but allowing slippage. Engaging VTM-4 Lock would lock the center diff to send equal power to both front and rear differentials but leaving the rear differential unlocked, performing like a part-time 4WD system with open differentials front and rear. If VTM-4 not locked was sending power to the rear I wasn't seeing it.

With this in mind, it appears your VTM-4 system is working as others have seen it work. I think you are over stressing the system with your hill climb and extra load.

I would highly suggest you get a vehicle with a higher towing capacity, like a truck or large SUV which can handle this better. If the information I'm seeing is correct, the towing capacity is 4,400 lbs. When you look at this number, it's not only the weight of the trailer, but the weight of all equipment, fuel, and people you are carrying as well. The trailer may weigh 2,200 lbs, but with the addition of two grown adults (300-450lbs total - throw in kids it's even more), equipment (500-700lbs), fuel (~100lbs), etc, etc, etc. This adds up quick where you can quickly max out your vehicles capacity. Now, throw in that you are going up a hill (steep, as you said) and you have a further burden on your vehicle.

I'm not going to tell you which vehicle to get, as my opinions would quickly get in the road. What I will tell you is to get away from an AWD vehicle and get a 4WD vehicle. You might now ask, "What's the difference?" ... The difference is, the AWD system is full time on, while the 4WD system is selectable. The big thing you are looking for with a 4WD system is the availability of a low range. By utilizing a low range, you effectively double (depending on the system, this will vary ... I'm using "double" generically) the amount of torque your engine is putting to the ground, leveraging mechanical advantage to do so.

The second thing you need to make sure the vehicle has is a true locking differential. It does not sound like your Honda has one. If you are curious, do a test as described in the excerpt I provided. It is a very good suggestion without putting undue stress on the vehicle your are driving. Ford, GM, Dodge, and Toyota (to name a few) all utilize this type of differential in their trucks. It will be mentioned on their window sticker if new, or if used, you can easily have the VIN run to see what options were installed on the vehicle when new (take the VIN to the corresponding manufacturer's parts department ... they can pull this information for you - if they are willing. I said "can" ... doesn't meant they will, lol.)

The third thing I'd look for is to ensure the vehicle is a true rear-wheel drive. Most large trucks/SUV's are setup this way. Rear-wheel drive is going to be a lot more effective while towing a vehicle than front wheel drive. This is because the weight of the trailer is providing weight over the main drive axle, which means you'll have better traction.

The other thing which I would tell you to do if not doing so already, is your driving technique. Ensure you are not "balls-to-the-walls" when going up the hill. You are again, just causing undue stress on your vehicle. The slow approach will provide you more comfort on the way up, as well as make it easier on your vehicle. You are trying to avoid wheel slippage if at all possible, which I believe may be at the root of the issue to begin with.

  • +1 for your nice answer. It is clear in my mind now that the Honda Pilot is not the vehicle I need. I thought it was considered a "large" suv but I was deceived. I understand that I need a differential that can truly lock mechanically and not by a slip clutch. I just didn't select your answer as THE answer because I would like to have a small list of vehicle that would work for me (in the SUV category). What is "balls-to-the-walls"? – Guillaume Bois Dec 10 '14 at 16:36
  • @GuillaumeBois ... balls-to-the-walls = "A lot of gusto", or gunning the engine, spinning the tires, making a go of it, using the brute force of the vehicle instead of finesse. As for a list, you actually shouldn't get a list of vehicles in an answer. It's not really keeping with the tenants of an SE site. One of the reasons being, the list I give you "today" will be outdated "tomorrow". I gave you enough information you should be able to find a vehicle which will suit your wants/needs without telling you what to buy. I don't want to give you biased information, so take it as you will. – Pᴀᴜʟsᴛᴇʀ2 Dec 10 '14 at 19:27
  • Before giving up, see my answer. – kmarsh Aug 21 '16 at 3:14
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It sounds like you're still in Drive and/or going too fast. You have to be in a low gear AND stay below 18MPH for lock to stay engaged.

From Honda:

  1. The vehicle must be stopped with the engine running.
  2. Move the shift lever to First (1), Second (2), or Reverse (R) gear.
  3. Press the VTM-4 Lock button. The light in the button will come on.

The VTM-4 Lock will temporarily disengage when the vehicle speed exceeds 18 mph (30 km/h). It will automatically engage again as the speed slows below 18 mph (30 km/h). The button light will remain on.

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