Speedo Calibration

[Bakes]

After installing 35s I updated my tire size with forscan but end up with a bodycm code. I haven't checked the actual accuracy of the change yet to see if it's really working but I assume it is. I looked around for a fix for the DTC and found this module that mounts behind the instrument cluster. Has anyone tried this yet?

17-23 Ford Truck Hypertech In-Line Speedo Module 730125

www.stage3motorsports.com

 

[miff01]

You need to retrain the TCM & PCM modules to clear the DTC

 

[Bakes]

You need to retrain the TCM & PCM modules to clear the DTC

I retrained the PCM but saw no option to retrain the tcm.

 

[ChsTremor]

Not sure what you did but I didn’t have a code after the forscan mod. I followed the directions in the forscan thread on here.

 

[Rxm488]

I used a flascal from superchips to adjust for the bigger tires Speedo was off like 3-4 mph at 70 now it’s accurate. really easy to use but kinda expensive.

 

[jonesy23]

I used a flascal from superchips to adjust for the bigger tires Speedo was off like 3-4 mph at 70 now it’s accurate. really easy to use but kinda expensive.

Other than that and Bambi mode use it for anything else?

 

[Fozzy]

After installing 35s I updated my tire size with forscan but end up with a bodycm code. I haven't checked the actual accuracy of the change yet to see if it's really working but I assume it is. I looked around for a fix for the DTC and found this module that mounts behind the instrument cluster. Has anyone tried this yet?

17-23 Ford Truck Hypertech In-Line Speedo Module 730125

www.stage3motorsports.com

Pretty sure thats what TC Custom uses on all their trucks. But ForScan works very well if done right. I was 11% off with my 37’s. Now I’m 0.5% off using the GPS method with no codes or problems since doing it.

 

[Ehabmxd]

hello guys
my tremor 275/65/18 from the Dealer and the GPS now is Accurate
i want to go with 35x12.5R18 tires or 295/70/18

can i recalibrate accurate GPS speedo ? or well be some differences

and which tool should i get to recalibrate ?

 

[jonesy23]

There will be difference l. I used Superchips Flashcal. You can use forscan much cheaper though.

 

[Ehabmxd]

There will be difference l. I used Superchips Flashcal. You can use forscan much cheaper though.

i meant after u recalibrate still not 100% Accurate ? Between Car and GPS ?

 

[jonesy23]

i meant after u recalibrate still not 100% Accurate ? Between Car and GPS ?

I’m 100% spot on with Flashcal. Need to play with a little. Size is smaller than you think when tire is loaded and compressed. I have 34.4 tire unloaded Flashcal has me I think somewhere in 33’s

 

[jmarshall828]

After installing 35s I updated my tire size with forscan but end up with a bodycm code. I haven't checked the actual accuracy of the change yet to see if it's really working but I assume it is. I looked around for a fix for the DTC and found this module that mounts behind the instrument cluster. Has anyone tried this yet?

17-23 Ford Truck Hypertech In-Line Speedo Module 730125

www.stage3motorsports.com

Is it easier to keep whatever tire size is in FORSCAN (assuming its pre loaded to factory OEM Specs of 275/70/18) and just change the FORSCAN BCM entry for the tire circumference size to 2791 which is 35x11.5?? I'm not too familiar w/ FORSCAN and want to make the change, but see everyone changing their tire size is getting additional codes opposed to just changing the circumference size.

TIA

 

[Aliass24]

Is it easier to keep whatever tire size is in FORSCAN (assuming its pre loaded to factory OEM Specs of 275/70/18) and just change the FORSCAN BCM entry for the tire circumference size to 2791 which is 35x11.5?? I'm not too familiar w/ FORSCAN and want to make the change, but see everyone changing their tire size is getting additional codes opposed to just changing the circumference size.

TIA

You have to do a pcm relearn after making the tire size change and then you should be able to clear the dtc’s.

 

[jmarshall828]

Ok thx. I was hoping to just change the tire circumference size & be good to go. TIA