Does anyone know where the vehicle speed senor location is? I tried tapping into pin 44 on C2 (50pin) off the ECM with no luck. Anyone have any thoughts?

thanks in advance.

 

Its for an 06 CTD 2500

 

it picks speed up off the tone wheel in the rear diff. atached to the carrier

 

It is definately pin 44 on C2.

What are you hooking to it or what are you looking for on it? You are not going to be able to just get a + or - out of it. That will be a square wave pulse.

If you let us know what you are doing or trying to do maybe we can help?

 

I would also like to know. I need to hook one up for my in dash navigation (Eclipse head unit) and I was just going to tap into the speed sensor on the transfer case, but I can't tell which wire is positive and which one is negative. There is no way to test them, obviously. It will be much easier to tap into the VSS itself, instead of messing with the wire loom at the ECM. Plus I dropped the wire down next to the shifter and it's already sitting on top of the tranny, it's just in the right place to wire it up there if I can figure out which wire is positive.

The tone ring in the rear axle does low speed readings, the VSS on the tranny/transfer case does the higher speed stuff. There are two VSS readings on our trucks. The front ABS sensors also come into play. You have all of that going to the ECM, so there is no telling what kind of signal that particular pin is getting/showing.

 

The in dash navigation should use the GPS for ground speed?

The VSS signal is not going to be a positive or negative signal. You are going to have a sensor with a power and ground and then a signal line. the signal line is where the data is and you head unit is most likely not going to comprehend a square wave pulse that it has to count.

 

Yeah the in dash uses GPS to get speed but by hooking up the VSS, it's much more accurate. It gets it's reading through 3 feet of 18 gauge wire, as opposed to several miles of air, to a satellite, then back.

So then where should I hook this up, at the ECM? If that pin didn't work for the original poster, what else should we look for? My service manual shows several VSS inputs.

 

The GPS alone will be plenty accurate for navigating. What that wire is good for is when you go through tunnels or under heavy tree cover and loose satellite lock it will accurately predict your location and keep you on coarse until you pick up the signal again. There's no need to hook up this wire unless you really want this feature. Portable units don't have this connection and do just fine.

 

I'm trying to connect an in dash Eclipse navigation unit. I've already connected it to pin 44 on c2 (ECM) with no luck. The gps unit does get a speed pulse but without connecting the VSS you cannot get route guidance which is a nice feature to have.

There are several VSS spots under the hood but none available to diesel engines (Ex. Anti-lock break module).

I just spoke with a dealership and they suggested connecting it to the speed sensor off the rear differential and not the transmission. The dealership mentioned connecting to the transmission would cause irregular shift points.

I hate running a wire back to the rear diff and will try to find where it connects under the hood. Any one have any experience with this?

 

hi
on the 2003 ram is the speed signal orange cable with withe tracer.
i have found this signal on C130 Pin C4 ore C1 from anti look brake controller Pin 12.

the pin 44 on c2(ecm) is not used on 03 truck. is pin 11 on c2 from ecm
but i think is not the same on 2006 truck.
chris

 

Which head unit? I got the AVN7000 and it does route guidance without the VSS wire hooked up.

In case yours is a DVD model, just an FYI... the "parking brake" wire can be wired to any ground source, then you can watch DVD's without having the parking brake on. I like to be able to slam a DVD in when I'm driving with some friends so they can watch. I thought the parking brake thing was dumb because if I'm going to park somewhere to watch a DVD, it's going to be at my house, not in my truck.

 

I bought the older model, avn 5435 on sale. Thanks for mentioning the parking brake tip. I too grounded it, but found having it always on park affected some of the features in the nav so i placed a switch between the unit and the ground allowing me to turn it off and on when i please.

Anyways, if someone comes up with a good spot to tap into the VSS please let us know!

thanks

 

Looks like you can now buy a can bus adapter that provides the signal see http://peripheralelectronics.com/web/onstar.asp Model chyah05