Speedo VSS wire?

[TooManyFords]

I'm installing my new Autometer gauges this week and read through the new speedometer instructions. They say I need to tap into the VSS wire from the transmission before the PCM to get an accurate signal. I did search before asking and there was only one thread that mentioned the VSS on our 4R70W transmissions. It basically said that there is probably a plug where the old-style cables-with-gears would plug in but that there was nothing there.

1. Where does the computer pick up the VSS signal from?

2. Is this wire in the loom somewhere under the dash? If so, what color and where will I find it?

3. If it does not use a VSS device, what do I need to buy to plug into the transmission cable hole to give me a VSS signal?

Thanks in advance everyone.

John

[Zack]

Cant help you, sorry!

[wchain]

Try Pin 14 on your stereo harness.
http://www.mercurymarauder.net/showcase/files/3/5/4/8/ford24.jpg

[TooManyFords]

Hey Wes!

:wave:

Is that pre or post PCM? I will try it and see regardless.

[wchain]

TMF, Not sure.

There is a VSS on the pumpkin on the rear axle, and there is a VSS on the driver side of the tailshaft.

[magindat]

Post PCM. It will show the adjusted reading for gears and tire size (revs/mile).

[TooManyFords]

Post PCM. It will show the adjusted reading for gears and tire size (revs/mile).

The documentation warned not to use Post PCM, but I can try it and see. I'll just have to crawl around under the car this week.

:D

[magindat]

The documentation warned not to use Post PCM, but I can try it and see. I'll just have to crawl around under the car this week.

:D

It's the signal used by the stock radio for the variable speed volume. Also used by aftermarket GPS radios for navigation.

Wonder why not post PCM?

What's the brand and model of guage? Mind if I research?

Afterthought: It's the same signal that gives the speed on vehicle dynamics for Pioneer. Does it have calibration internally for gear and rev/mi?

[TooManyFords]

Not at all, help yourself!

http://www.autometer.com/tech_faq_answer.aspx?sid=2&qid=9

It is an Autometer Nexus Speedometer, but from their site it looks like all the speedometers use the same setup.

Cheers!

John

[BAD MERC]

It will be gray/black in the radio harness.

[magindat]

It will be gray/black in the radio harness.

True.

If you have an aftermarket radio, this is often provided in the aftermarket harness as a brown.

[magindat]

Not at all, help yourself!

http://www.autometer.com/tech_faq_answer.aspx?sid=2&qid=9

It is an Autometer Nexus Speedometer, but from their site it looks like all the speedometers use the same setup.

Cheers!

John

Sounds like trying the VSS by the radio won't hurt, but may not work at all.

try to contact Drock96maquis (sp?). He has been an excellent source of wiring information.

[offroadkarter]

I'll bring him to the thread

[vonirkinshtine]

*drammatic music Indianna Jones music*

SUMMON THE D-ROCK!

ooooooOOOOOOOOoooooooOOOOOOOOO Ooooooo

[ChiTownMaraud3r]

I had to tap into the VSS for the AVIC, I believe it is under the dash on the right side of the wheel...its been a while. Pin 18 of the gray connector if I recall correctly? Someone back me up please..

[offroadkarter]

*drammatic music Indianna Jones music*

SUMMON THE D-ROCK!

ooooooOOOOOOOOoooooooOOOOOOOOO Ooooooo

I have, les hope he comes ;)

[Spectragod]

Try Pin 14 on your stereo harness.
http://www.mercurymarauder.net/showcase/files/3/5/4/8/ford24.jpg

I have used this as a source for radar/VASCAR units in other Ford vehicles, it works like a champ.

SG

[Drock96Marquis]

I got paged... :drug:


I'm installing my new Autometer gauges this week and read through the new speedometer instructions. They say I need to tap into the VSS wire from the transmission before the PCM to get an accurate signal. I did search before asking and there was only one thread that mentioned the VSS on our 4R70W transmissions. It basically said that there is probably a plug where the old-style cables-with-gears would plug in but that there was nothing there.

1. Where does the computer pick up the VSS signal from?

2. Is this wire in the loom somewhere under the dash? If so, what color and where will I find it?

3. If it does not use a VSS device, what do I need to buy to plug into the transmission cable hole to give me a VSS signal?
03+ panthers do not use the VSS. Instead, the transmission's OSS sensor is used. The PCM uses this input and vehicle speed is calculated for the overall rear axle ratio programmed.



Speedometer/Odometer

The speedometer and odometer provides speed information based on a speed/distance signal from the PCM. The PCM receives the vehicle speed information from the output shaft speed sensor (OSS).


Output Shaft Speed (OSS) Sensor

The output shaft speed (OSS) sensor is a magnetic pickup, located at the output shaft ring gear, that sends a signal to the powertrain control module (PCM) to indicate transmission output shaft speed. The OSS sensor is used for torque converter clutch (TCC) control, shift scheduling and to determine electronic pressure control (EPC).

Output Shaft Speed Sensor
The Output Shaft Speed Sensor (OSS), provides the Powertrain Control Module (PCM) with information about the rotational speed of an output shaft.The (PCM) uses the information to control and diagnose powertrain behavior. In some applications, the sensor is also used as the source of vehicle speed. The sensor may be physically located in different places on the vehicle, depending upon the specific application. The design of each speed sensor is unique and depends on which powertrain control feature uses the information generated.
That said, there is no PRE-PCM VSS signal to tap on an 03+, as the PCM generates it (based on OSS)

So you have a few options.
You can tap the VSS signal going to the cluster or radio for accurate vehicle speed. Either one is fine, it's the same signal just spliced to both. It can also be tapped at the overhead console, the LCM, the cruise servo/wiring or splice from the PCM wiring.
It appears you are working on an instrument cluster w/ new gauges so the existing cluster wiring would be ideal. But, it is of course post-PCM as it's being generated by the PCM.

If PRE-pcm is a must, you may have another option. Most 03s still had the provision in the tailshaft housing for the VSS, with a plug. Later the plug was ditched all together. Take a peek under the car and see if you notice the plug on your tailshaft, if so, you could mount a VSS. You need to select the correct gear for your overall tire diameter and gear ratio (post it in here and I will figure it out for you). All the sensor needs is ground and the signal return goes straight to your new gauge. But, there is another problem. Even if you have the provision, your output shaft may not have the VSS drive teeth on it - as it was removed for most by mid 03 MY.
If you have the plug, remove it. Stick your pinky in and see if you can feel drive teeth directly below. If so, the sensor retrofit is possible.



IMO, I wouldn't bother trying to install a standalone VSS. I would just use the existing PCM VSS signal for your new gauge.

You still have the OBDII/SCP databus setup in your Marauder, right? When you set up the new gauges use your laptop with LiveLink to monitor vehicle speed to make sure it is accurate (or a scan gauge if you have one)

[TooManyFords]

Someone should "sticky" this thread as Drock96Marquis has posted the definitive VSS info!

I'm pulling both the radio and the cluster this weekend so I'll try the cluster wire. Which one is it?

As for the axle info, the Autometer gauge has its own "learning" system so it works without knowing what is in the car or if I change anything. And seeing that I've got a TH400 tranny sitting in the garage to go in, this is a temporary solution. I'm just impatient and want to see the new gauges working before the tranny is swapped.

Once that swap happens, Autometer makes a TH400 VSS adapter that I'll install and do the "learn" over again.

Thanks!

John

[Stranger in the Black Sedan]

Seriously, we have speed sensitive volume control? I would have never noticed if you guys didn't mention it. The car is so quiet inside stock that the stereo doesn't have much road noise to contend with. I think some of the guys on this board need muffler-volume sensitive radio control though.

[Drock96Marquis]

I'm pulling both the radio and the cluster this weekend so I'll try the cluster wire. Which one is it?

It's a gray wire with black stripe on pin 2 of the white cluster connector.
Pinout:
http://www.supermotors.net/vehicles/registry/media/569771_1

(Use the 03-05 pinout set in that link)


The VSS+ wiring color stays the same throughout the vehicle, so if you decide to tap it elsewhere just remember GY/BK

[Raudermaster]

Derek! What's up man?! Long time no talk. I can't believe you got a Saleen blower to fit on your car, you are absolutely nuts. Pics ASAP!!

[Drock96Marquis]

Jarod! How's it going?

Just wrapped up the Saleen install about a month ago. Pictures (http://www.supermotors.net/vehicles/registry/7603/64467)


What's that I see in your sig, 445rwhp!?! I think you're the one who's nuts :P That thing is a BEAST, that's awesome man! I took a look through your gallery pictures with it installed, too :cool: Had to get the bling polished head, huh? :D

But, for sale? What's up with that? Shoot me a PM and fill me in.

-Derek

[magindat]

Just wrapped up the Saleen install about a month ago. Pictures (http://www.supermotors.net/vehicles/registry/7603/64467)

:Offtopic:

That, sir, is most impressive.

[Pops]

You have my vote, it looks great!