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Holmeslice
06-22-2013, 05:42 PM
Hi All,

There's a lot of info on this forum about adding trailer hitch wiring to vans that didn't come with a factory hitch. There seems to be two trains of thought:

-- Install the wiring using an aftermarket harness. Easy to do, and cheap.
-- Try to find a dealer to do the wiring after the fact so as to tie into the computer system, which for most has been unsuccessful.

For me, since this is the first NEW vehicle I've ever owned (2011 144" Crew), I'm trying to go by the book on most things. The warnings about not being able to activate the Trailer Stability Module (TSM) when you do the wiring yourself resonated with me. So, I called around the Tri-State area (I'm in New York City) to probably 10 different places, and ended up right back at the dealer I bought the van from - Diehl's Freightliner. I had already bought a Curt 600/6000 hitch and installed it, and explained this to my dealer. I told them I wanted to get the OEM wiring job done, with all the modules activated, as though the van had come pre-wired from the factory. Surprisingly, my dealer was the only one who didn't blanch at this thought. The harness cost 204 dollars (says "chrysler" on the 7-pin flap). The install was $720-something-dollars. Not cheap, but an extravagance I had allotted for in my purchase of the van.

Today I picked it up. I made the service manager assure me for the 20th time that the system knew when the trailer was connected, and the TSA would activate automatically.

I won't be pulling a trailer for the next month or so, so won't have any confirmation otherwise. But I have to assume they knew what they were doing and talking about.

So, I'm cautiously pleased to say it can be done, after the fact. :cheers:

-Kenny C.
NYC

pfflyer
06-22-2013, 06:12 PM
When I bought mine from the dealer last month I wanted a hitch with factory wiring tied to the stability module. This was a $1000 option installed by the dealer. He said the only way it could be tied in was at the assembly line and their hitch and wiring for $1000 was no different than diy install or a hitch dealer install just $400-600 more expensive. Don't know if he knew what he was talking about but I was wondering if the trailer started swaying the rear of the van wouldn't the Stability control on the van kick in?

sailquik
06-22-2013, 08:22 PM
pfflyer,
Think about this:
If your Sprinter has the normal ASR (Anti-Skid Recovery) system fully functioning, the ASR system will individually apply one of the brakes any time the inertial sensor
sees any yaw (right or left turning moment parallel with the roads surface) or roll (tipping of the van on the longitudinal axis) that exceeds the values programmed
into the ASR system.
If you add a trailer, and the trailer sways or becomes unstable, which individual brake would you apply to straighten out your trailer, or the entire Sprinter/trailer
package.
Think this through and I think you will see pretty clearly that the physics involved in keeping the Sprinter straight differ significantly from the physics involved in
keeping both the Sprinter and a trailer straight.
This is what the Trailer Stability Package will do for you. It will sense the trailer hitched to the back of your Sprinter and alter the ASR program to react to the
whole package, rather then just the Sprinter.
Is this important and will it keep you safer?
My experiences say yes, it is a valuable safety feature if you ever need to tow a trailer.
I continue to be amazed by dealers that fail to "make the customer happy".
The factory towing package for the 2010-2013 Sprinter only costs $395 (it's Option PT1).
This gets you the hitch, factory installed wiring for all but the electronic brake controller which is pre wired you just need the green mating connector and pins)
and any modules under the drivers seat that give you the TSA (Trailer Stability Assist) feature.
Why can't the dealers do what the dealer I work with has done. I tell them what I need and they either have it in their inventory, or they go out and
get the vehicle I need from another dealer. Car dealers have always done this! If they don't have the color or options you want, they can trade around with
other dealers to find the vehicle with the right color and options.
I just ordered my 2014 4 cylinder 7 speed yesterday and this cost has gone up to $410 (Option code X22).
Roger

Holmeslice
06-23-2013, 01:29 AM
Good post, Roger.

Since I don't own a trailer and can't physically test just yet, is there some visible indication (perhaps a TSA module under the seat, as you say?) that I can see to confirm this installation was more than just a Benz dealer doing a glorified aftermarket install?

sailquik
06-23-2013, 02:10 AM
Holmeslice,
Yes there should be a couple of modules up on the top bars under the drivers seat. One is for trailer brakes and the other is for the
TSA if I recall correctly. If you have these 2 modules, then the dealer has installed the full system.
There is no indicator that I know of that will tell you that the TSA is operational, even if you have a trailer. I just did a 2000 + mile
trip and if the TSA was ever activated I didn't recognize it. But my trailer tows so nicely. It's a lot of weight, so you know it's back there,
but it has never swayed around at all, even in strong crosswinds. It does the same a the big semi-trucks, if you look down the side of the
trailer, the rear of the trailer is not in perfect alignment with the rear of the cab due to the pressure of the wind pushing the trailer sideways.
Roger

Sprinter SS
06-23-2013, 03:46 AM
Home slice...

Did the wiring harness have a bunch of relays at the rear end of the van on the Chrysler harness? That was the version they sold when dodge was representing the NCV3.

Just curious..any pics of the curt hitch? Factory step bumper?

atulin
06-23-2013, 04:09 AM
I just ordered my 2014 4 cylinder 7 speed yesterday and this cost has gone up to $410 (Option code X22).
Roger
It will be interesting to see how you like towing with the 4 cylinder. I'm probably going to renntech mine to to give it some help towing in hilly areas. Did you order another 3500?

CJPJ
06-23-2013, 04:58 AM
bty: OEM Factory Trailer Hitch Wiring and the turd poor factory routing of the wires!
53018
I repaired the cut wires & rerouted the wires over the top of the tube.
53019 Now that I look at the picture:... Probably the plugs bracket and its two bolts could be fastened from above for their additional protection.

sailquik
06-23-2013, 05:39 AM
Atulin,
Yes, another 3500 with the 4.182:1 rear end ratio.
With the 7 speed, you might find you have no issues pulling hills, unless they put the extra 2 gears as overdrives like the NAG-1.
I'll have a look and see what the ratios are if I can find it.
OK, update:
I looked up the Mercedes G-Tronic 7 speed. I sure hope they know what they are doing.
Here's what I found for the ratios:
7G TRONIC 1st 4.377 2nd 2.859 3rd 1.921 4th 1.368 5th 1.00 6th .82 7th .728 R1 3.416 R2 2.231 Two reverse gears?...only MB knows why??
5G TRONIC 1st 3.59 2nd 2.19 3rd 1.41 4th 1.00 5th 0.83 R1 -3.16 - R2 1.93 This is the trans we know as the NAG-1! Anyone else know we have 2 reverse gear ratios...I sure did not!
Not sure I agree with the spacing of these ratios, but with a 4.377 1st gear it should pull stumps nicely. I'm going to have to learn to run at lower revs as
it looks like that's where they are getting the 18% better fuel mileage, but there will still be some choices as we can go up/down through the gears manually
just like the NAG-1.
Looks like the new Euro 5 spec OM-651 has very similar torque and Horsepower curves as the OM-642 V6 so the extra gears may really give us what we need.
OM-651 output 120 kW (163 hp) at 3800 rpm, max. torque 360 Nm at 1400-2400 rpm (Very similar to the 2013 OM-642. Not sure if these will be BlueTec (SCR/DEF)
or not. They meet the Euro 5 emissions Spec. without the SCR, but you can almost bet that the EPA will require it here in North America... our tax dollars at work...
yeah right! So the little 4 cylinder 2.1 liter will be making max. power @ 3800 RPMs, so the 2800-3200 sweet spot may still be applicable. Can't wait to try this out
on the road!
No "Tunes" for me. Never been necessary if you use the engine in it's most efficient rev range.
Also, I like to keep my warranties valid.
Roger

Holmeslice
06-23-2013, 02:09 PM
Holmeslice,
Yes there should be a couple of modules up on the top bars under the drivers seat. One is for trailer brakes and the other is for the
TSA if I recall correctly. If you have these 2 modules, then the dealer has installed the full system.
There is no indicator that I know of that will tell you that the TSA is operational, even if you have a trailer. I just did a 2000 + mile
trip and if the TSA was ever activated I didn't recognize it. But my trailer tows so nicely. It's a lot of weight, so you know it's back there,
but it has never swayed around at all, even in strong crosswinds. It does the same a the big semi-trucks, if you look down the side of the
trailer, the rear of the trailer is not in perfect alignment with the rear of the cab due to the pressure of the wind pushing the trailer sideways.
Roger

Hi Roger,

I got up this morning and went out to the van. I took some photos of the wiring under the seat then compared the photos with others I'd taken the day I got the van. I don't see any change - no extra modules, in fact not a lot of evidence of any wiring changes at all. I do know they had the seat out of my van though, as the seat belt had been off and reattached, but twisted, so someone has been in there. And there certainly is a long harness running along the frame rail under the van that enters under the seat. There were no relays visible. Hmmmm. I want to believe my dealer did what I asked, but I'm now a little unsure.

-Kenny C.
NYC

sailquik
06-23-2013, 02:30 PM
Hi Kenny,
Is there a light green 4 pin connector down in the bottom of the seat box?
It usually ends up just below the fuse block on the LH side of the drivers seat.
Do a search on "Green Trailer Connector" on the Yahoo Sprinter Group and you can see what the connector looks like and how the color code is configured.
I'll see if I can get a photo and some part numbers off the 2 modules in my 2012.
I looked, and decided I'm not taking the drivers seat out to get the photos. Actually, they do exist, somewhere on this forum or the Yahoo Sprinter forum.
Photos of the modules with the part numbers as I recall.
Roger

Holmeslice
06-23-2013, 05:01 PM
Hi Kenny,
Is there a light green 4 pin connector down in the bottom of the seat box?
It usually ends up just below the fuse block on the LH side of the drivers seat.
Do a search on "Green Trailer Connector" on the Yahoo Sprinter Group and you can see what the connector looks like and how the color code is configured.
I'll see if I can get a photo and some part numbers off the 2 modules in my 2012.
I looked, and decided I'm not taking the drivers seat out to get the photos. Actually, they do exist, somewhere on this forum or the Yahoo Sprinter forum.
Photos of the modules with the part numbers as I recall.
Roger

Hi Roger,

I looked again. Nothing. The only thing new that is under my driver's seat is the plastic covered harness that comes in from under the van, then immediately exits and goes forward to the battery compartment. I pulled the lid on the battery and it's a dark wire (black - negative), a red wire to hot, and a blue wire that is taped off.

So, there are no modules. There are no new connectors under the seat. I looked at the 7-pin terminal at the hitch and there is a couple of harness branches that run to the tail lights, but I don't see any evidence of anything connecting to any can bus electronics, unless it's running up across the top and into the van somewhere else. I'm starting to think I got shafted.

Ugh. When I picked up the van on Saturday I spoke directly to the service manager and again asked if the Trailer Stability Assist would be automatically activated when I connect, and he said yes.

I know just enough to ask the right questions, but not enough to know what to physically look for. I do think he's an honorable guy, but maybe he doesn't even know what I'm trying to do? I looked at the invoice and it says: "Installation of trailer harness, mount and retrofit wiring harness from the distribution center under the drivers seat to the connector. Secure and seal all connections as per OEM recommended procedures." But there is nothing that I can see that's connected under the drivers seat to any computer - just a 3-wire loom passing through that compartment to the battery compartment under the driver's feet.

pfflyer
06-23-2013, 05:02 PM
Roger,

Is the TSA as effective with a trailer with out brakes?

Patrick

sailquik
06-24-2013, 03:42 AM
Patrick,
I do not believe that the TSA actually applies the electric brakes on the trailer, so the overall safety benefit of this feature would be the same with or without
electric trailer brakes.
The TSA is a global "feature" so it has to work with electric brakes in the USA, hydraulic surge brakes in Europe and the UK and whatever they use in Australia/New Zealand.
So, the TSA just knows there is a trailer on the back, and when it begins to sway, it will apply the appropriate individual wheel brake (s) in the Sprinter.
Roger