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Discussion Starter #1
Wife got a ticket yesterday for 36 in a 30 zone and the 20's and 305/55/20 toyos put the speedometer about 5-6 MPH low...
so is the truespeed the way to go? are there any other products worse? better? whats this thing cost and where did you get it?
TIA!!!
Tom /ubbthreads/images/graemlins/biggrin.gif
 

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It's about $200. Some programmers (I think the Flashpaq and Hypertech, more too) also can calibrate for tire size/gear changes as well. I have the Truspeed, it's nice and you can really fine tune it. You'll have to loosen up the inner fender on the drivers side to get the the ABS module. Do not try to go from up top, wasted my time trying it that way.

Matt

edit: I got mine from AutoAnything.com
 

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I got mine for 180 from a local dealer. Works great. But I have seen a few on here that have had some issues...

I do think it is the way to go.. easy installation..
 

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I've had issues with one of mine, but got it replaced and never looked back. It helps your tranny out by shifting at the correct shift points because your speedo is not reading correctly.
 

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Hey Tom. How's it been going?

A dealer should be able to reprogram your PCM to correct the speedo with tires up to 35". I know when I had 35s, it was no problem getting it done. You just have to know the revs per mile for your tires.

SmokeyWren has the exact formula for the dealer tech to use. Maybe he'll chime in.

Mark
 

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[ QUOTE ]
A dealer should be able to reprogram your PCM to correct the speedo with tires up to 35". I know when I had 35s, it was no problem getting it done. You just have to know the revs per mile for your tires.

SmokeyWren has the exact formula for the dealer tech to use. Maybe he'll chime in.

Mark

[/ QUOTE ]

The Ford directions I have are as follows...

Calculating Tire Revolutions Per Mile

Position vehicle on level ground, load with the standard weight for the specific application, and inflate the tires to the recommended pressure (ensure that the tires are cold).

Measure the tire height from the ground to the top of the tire in inches. Ensure an accurate reading to the nearest 1/8 inch.

Divide 20,168 by the tire height in inches to get the tire revolutions per mile.

Example: Measured tire height - 33 inches.

revolutions/mile = 20168/33 = 611 revolutions/mile
 

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SmokeyWren has the exact formula for the dealer tech to use. Maybe he'll chime in.
Toyo LT305/55R20 tires are 625 tire revs/mile. Click here. So most Ford dealers probably have someone that can calibrate the speedo to 625 revs/mile.

The following procedures are several years old. Ford techs have newer, better diagnostic tools to use now than when this first came up for the '99 models. The WDS has now been replaced by a newer diag system. But maybe print it out and give it to your tech anyway. If he's been around more than a few years, he'll probably be able to adapt the following procedures to whatever is the newest diag system.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

If you dealer's tech hasn't calibrated a speedometer on a SuperDuty before, he might spend an hour researching on how to do it before he actually does any work. After he has done a couple, then it's a 5-minute job – but most dealers will charge you one hour of labor to do the job.

If your service writer sounds like perhaps that dealership is not experienced in calibrating SuperDuty speedos, then copy and paste the following into a Wordpad or Word document, print it out, and give it to the service writer ot tech.

1) Ensure all harness connections are plugged in.

2) Using Rotunda New Generation Star (NGS) scanner and Version 3.2 or higher Service Card, Plug into the DCL connector.
• [ADDED: Do not use a service card version later than early 2001 model year. This will not work if you try to use a service card dated after the 2002 models came out. ]
• [ADDED #2: Ignore the above "ADDED" if you use the newer NGS Plus. With the NGS Plus you can calibrate the speedo on any 7.3L or 6.0L PSD.]
[*] [Added #3: Some techs now use the Ford Worldwide Diagnostic System (WDS) to calibrate the speedo. I don't know anything about how they do it.]
[*] Oops! Time flies and the WDS is now obsolete. You're on your own with whatever diag system is now in use. :(

3) Turn Key on w/Engine Off.

4) Select Service Bay Functions

5) Select ABS Module or 4WABS Module depending on application.

6) Select Tire Size/Axle Ratio Configure.

7) Enter tire manufacturer's specification of revs/mile (tire revolutions per mile) into the NGS as the REV.PER MILE figure.
• [ADDED: To have an even more accurate odometer, enter the following rev/mile:

For 285/75R16 tires enter 00636
For 295/75R16 tires enter 00626
For 315/75R16 tires enter 00601
For 305/55R20 tires emter 00625 :cool:

Do not try to enter a number less than 00601 with the old NGS. With the newer NGS Plus or WDS, I don't know. ]

8) Select Tone Ring size and verify that 120 is programmed in.

9) Select <Option> and press TRIGGER.

10) Select <Vehicle> and press TRIGGER.

11) Press <Done> and the Module will be reprogrammed.

12) Check Speedo accuracy.

To determine your odometer’s accuracy (if you don't have that fancy newfangled GPS stuff) just find an interstate highway that has two mile markers 10 miles apart without being near an entry, exit, bridge, or overpass. When your front bumper passes one of these markers, push the odometer reset button to zero. Ten miles later, your odo should read exactly 10.0, which is 100 percent accuracy. Every tenth of a mile off from 10.0 is one percent error.

Some Ford dealers will refuse to calibrate the speedo. They say it can't be done - or that they're not allowed to do it. So in that case just refer them to the 2003 Ford gobbledegook version of the procedures at:

http://www.fleet.ford.com/truckbbas/non-html/2003/bb_pdf/206.pdf
 

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Discussion Starter #10
ok so with all that being said...I have a DP-Tuner 4 pos. chip which has disabled the trucks PATS system....is the dealer tech going to screw anything up by going in and recalibrating what he has to?
TIA
Tom
 

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I'm wondering the same thing. If I need to remove my DP will it overwrite the new dealership program when I hook it back up?
 

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for correcting the speed I suggest a "black box" the reason is - you can adjust it as many times as you want and you dont have to pay the dealer every time.

I am very familiar with these type of boxes

if anybody gets a black box and needs help with it... just find me

I know the super duties from 99-08 really well.

I have the speed wizard on mine i have a 2003 F250 4x4 5.4L engine.

BTW... if you have a 99-04 you do not need to hook it up in the engine compartment. My research showed that the tranny does not use speed as an input therefore if you would rather hook it in the cab, you can.

On 05-08 it must be hooked in the engine compartment though

Kenny
 

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ok so with all that being said...I have a DP-Tuner 4 pos. chip which has disabled the trucks PATS system....is the dealer tech going to screw anything up by going in and recalibrating what he has to?
TIA
Tom
No, the tech changes only the tire revs/mile parameter in the ABS module. They don't mess with the PCM.

However, a good rule of thumb is to NEVER turn your truck over to a dealer's tech unless you have reset the PCM back to stock. That's why most DP_Tuner chips include a stock setting.

If you don't have a stock setting on your chip, then communicate with the tech and make it plain that he is not to do anything except correct the revs/mile parameter in the ABS module. Or else, pull the chip until after you get the truck back from the dealer.

But with that warning, I've had the dealer calibrate my speedo three times while my chip was installed in the tow mode. I communicate with the tech, and he knows I have a chip and that's he's not to mess with the PCM.
 

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The tire size is in the GEM not the PCM
Not exactly. The tire revs/mile parameter is in the ABS module, not the PCM or GEM.
 

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for correcting the speed I suggest a "black box" the reason is - you can adjust it as many times as you want and you dont have to pay the dealer every time.

I am very familiar with these type of boxes

if anybody gets a black box and needs help with it... just find me

I know the super duties from 99-08 really well.

I have the speed wizard on mine i have a 2003 F250 4x4 5.4L engine.

BTW... if you have a 99-04 you do not need to hook it up in the engine compartment. My research showed that the tranny does not use speed as an input therefore if you would rather hook it in the cab, you can.

On 05-08 it must be hooked in the engine compartment though

Kenny



Maybe you should try talking to the tuners that control all of the peramiters of tuning. The VSS sends a signal to the ABS module. The ABS module processes it and sends a signal to the PCM and the PCM uses the input to control shifting. At least according to the tuners out there for our turcks.


Keep Strokin'
 

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Maybe you should try talking to the tuners that control all of the peramiters of tuning. The VSS sends a signal to the ABS module. The ABS module processes it and sends a signal to the PCM and the PCM uses the input to control shifting. At least according to the tuners out there for our turcks.


Keep Strokin'
good post... and as a matter of fact between my last bunch of posting and now I have talked to a custom tuner.

It ends up that only the 7.3 Platform uses the VSS for the tranny.

Now, I will agree NOW that it is best on all models to hook it up right after the ABS because then it does not matter what plat form you have.

I have the 5.4L gas in my truck and just today (just got done) I changed the location from behind the cluster to right after the ABS, and I verified it with my programmer (i can read speed according to PCM) and I tried all sorts of tests today, and no matter what I did - the truck always ran the same - which should be with my power platform. With the 7.3's it may be different. I dont have a 7.3 to test it on, so yes, I will take back part of my statement. It is ok to install behind the cluster on trucks that are 99-04 that are not 7.3 Diesels. But I have to recommend going to right after the ABS module.

I took tons of pics today and theres an even easier spot instead of way down by the abs connector.

Kenny
 
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