Tire size change alfaOBD

[heckcat9]

My recent experience with setting the tire size on my 2016 1500 with the latest AlphaOBD (v2.2.1.0) and MX+ reader...

I set my tire size to 2870mm per this post:

AlfaOBD

When, exactly, do you need the radio pin? I understand needing the pin for keys, but I have been reading (first from post 1 up, and alternately from the last post down) every free moment I have and haven't come up with an answer to that question. Thanks for any hint you can give me.

www.ramforum.com

I had issues getting the settings to work without error codes so I finally tried a known working circumference from the AlphaOBD thread. That actually didn't work either...

My actual diameter per the manufacturer is 36.69 inches for my 37x12.5 Cooper SST Pros.
Actual circumference in mm:
2928 = 36.69 × 3.14159 × 25.4
The delta is 58mm between 2928 and the 2870 I used, which results in the speedo being mostly accurate and off by much less than a mile, GPS and radar verified. Good enough for me.

As others have mentioned, the truck indeed had to "rest" for the changes to propogate, strange. I shut the truck off, locked the doors, and grabbed a drink for 30 minutes and after my trailer brake, ABS, wheel speed, etc error codes were gone and my speedo and cruise control worked.

The AlphaOBD menus have changed a bit as well, below are the menu items I chose:
Car model: RAM 1500 (DS/DX/DT)
Function:
Body Computer > MY2013-2017 PowerNet
Engine > Chrysler PowerTech/Pentastar/World/Hemi v6/v8
ABS > Bosch/Continental/Teves/TRW PowerNet MY2013+ PowerNet

Hope this helps avoid the headache I had changing my tire settings the morning of an 8 hour road trip lol.

 

[augiedoggy]

I joined to respond here. I also have used alpha to change the tire size on my 2015.. I have found it easier to just use "Torque pro" afterwards to clear all my codes if I get any at all. I found that when making small adjustments I dont always get any errors to clear. also there can be quite a time delay after changing setting. I have more than once had to walk away for a half hour. I also use a cheap $12 ELM327 obd bluetooth adapter I bought on ebay about 8 years ago. Ive since used it to also activate the rear view camera on my uconnect 5.0 stereo so I could add a cheap amazon backup camera. Ive also used it to turn on led and hid light options

 

[Azbr06]

So I’ve been searching and can’t really find anything about my issue. New to the alpha obd program and has been working great so far. So my issue is, I have a 2013 2500 with 35s. I got the mm I used 2791 which was off but the question comes after I set that I go to abs and I know the changes the continental/ate so I chose the right one for my year, but when I click on abs initialization on the next screen the start and stop is greyed out. Any reason why? It has the steps but how do I know if my truck has g sensor or ESC? Thanks for any help

 

[RAMRODDY]

Just did my 2020 1500 Classic. A few things were different, Maybe I have a newer version of Alpha? Most notably, Ate/Continental was not an option under ABS. I used Bosch/Continental and it seems to have worked fine. No codes or lights after a brief test run. Speedo is within 1 or 2 mph of Waze or another route app at 60 mph. Close enough for me. Thanks!

Did you need to use a security cable to do this? Having a bit of trouble flashing after choosing tire size.

 

[Bbroj]

Yes, I had a security cable. I may be mistaken, but I thought the security cable was only necessary for the newer 1500 Classics.

 

[TosaInu]

Quick write to help with this. However I bear no responsibility for any changes that you might not like. Only ones you do.

Start off with key in run.
Open app
Select dodge/ram button, Ram 1500 or 2500 From drop down, Body Computer, then body computer MY2013-2017
Connect then click on the icon at the bottom with the hood open
From the drop menu select "Program tire size"

Right above start on this page is a text box that allows you to input the tire circumference in mm or you can use the drop menu to select a preprogrammed size. (Best way to get your mm number is to measure mounted height and then do your conversion, always round up or down to a whole number. This might take a couple adjustments from that to get perfect at 60.)
View attachment 145954

Press start and it should take a couple seconds to complete.
Once done back out to main page.

Cycle the key, at this point you can get all kinds of lights on the dash, so then you need to do the abs module.

Now select dodge/ram button, Ram 1500 or 2500 From drop down, ABS, then ABS Ate/Continental
View attachment 145953


Connect then click on the icon at the bottom with the hood open
From the drop down select ABS iniatiliazation
View attachment 145952

Read the instructions

View attachment 145951

Go back to the drop down and select static ECU initialization
Press start and wait to complete
Click on the check engine icon and clear faults
Then cycle key
Click back on the car icon
Select clearing Rolls Information from drop down, then start
After complete clear faults in the Body control module and the engine.
Cycle key
Once complete start your ram and take it for a spin, and check speed vs a gps. If your still off you can redo the process and adjust as needed.

This was performed on a 2018 Ram 2500 with version 2.1.4.0 on a android with OBDlink MX and a bypass cable

If anybody has noticed any differences on their vehicles or has any input to edit this let me know.

Hoping someone can help with this. My screen shots were taken when NOT connected but I was connected when attempting all actions. It seems I had no issues changing tire size but when I go to clear the ABS faults I am not seeing an option for "ABS Ate/Continental"

The only option that really applies to my truck (ABS Bosch/Continental/Teves/TRW PowerNet MY2013+ Powernet) does not enable the Start button. The instructions seem to indicate that maybe I need to go thru a different procedure but obviously I am hesitant to do so as I am not looking for a disaster. Really, I'm wondering why I do not get the "ATE" option.


Any insight or help is greatly appreciated since my truck is now sitting in the garage with a bunch of fault codes. Thanks.

 

[TosaInu]

I got it working (so far anyway) by sort of following this post:

Used AlfaOBD to program TPMS and Tire size.. it worked, but with ABS/Camera faults?

Checked my speedo - reads 1 to 2 mph over GPS. fine with me, close enough. Probably factory specs. TPMS warning is gone. The only bummer was that when I backed out of garage, the rear camera gave me a blue screen. Hitting surround camera shows black screen. Went for a test drive, and...

hdrams.com

I still was not able to initialize ABS (start button never enabled) but I ended up clearing the rolls, resetting faults & then was left with a single nefarious fault still. It ended up being in the 4WD system, cleared that and so far everything appears to be good.

 

[TosaInu]

As long as I am talking to myself today, this may be covered elsewhere in the thread but I know there is a lot of discussion about getting your PIN from the dealership. I was never prompted for a PIN while doing the tire size change so I'm not sure what triggers needing that but in any case, you can actually use alfaOBD to get the PIN instead of going to the dealer.

Radio Frequency Hub->Your Control Unit->Press the "Hood" icon->Read PIN

 

[Brew99]

I believe the dev. added the PIN reading function in the android app v2.2.0, so prior to that people needed to get it from the dealer or use another android app to get it.. I know you need the PIN when resetting the RF hub (i.e. when changing TPMS)

 

[TRad]

I got it working (so far anyway) by sort of following this post:

Used AlfaOBD to program TPMS and Tire size.. it worked, but with ABS/Camera faults?

Checked my speedo - reads 1 to 2 mph over GPS. fine with me, close enough. Probably factory specs. TPMS warning is gone. The only bummer was that when I backed out of garage, the rear camera gave me a blue screen. Hitting surround camera shows black screen. Went for a test drive, and...

hdrams.com

I still was not able to initialize ABS (start button never enabled) but I ended up clearing the rolls, resetting faults & then was left with a single nefarious fault still. It ended up being in the 4WD system, cleared that and so far everything appears to be good.

The Start button will never enable. It is just telling you how to do it. Read the directions and complete both tasks to initialize your ABS. I was confused the first time i tried it. Good luck.

This worked for me...

Start off with key in Run position

Open App

Select Body Computer and select Connect

Select Hood Icon

Select “Program Tire Size”

Enter tire size and hit Start

Back out to main page…

Cycle Key

Select ABS

Select ABS control unit Continental and select connect

Select hood icon

Select ECU Initialization

Hit Start

Select Check Engine and clear faults

Cycle Key

Select hood icon

Select “Clear Rolls Information”

Hit Start

Clear Fault from the Body Computer and the Engine Computer

Back to main page

Cycle Key…..

 

[LaramieEco95]

Hey yall, I am having similar problems with the tire size not wanting to change. I have a 2018 Laramie 1500 eco with 295/65/20 tires added which are said to be 35.1".

I plug my OBDlink mx+ in the port and connect it to AphaOBD. I follow the steps to where you can manually put the circumference in. I used tiresize.com to find the size which was 2799 (I did not measure the mounted tire itself so it could be different). When I hit start it changes screens and shows me the tire size that I changed from (275/60/20). When I hit next it brings me back to the tire size select page where you can manually add the size. I type it in again to make sure it took but it won't do anything when I hit start. If I back out all the way and do the procedure again it will still say my old size is selected.

Am I doing something wrong or is there a step I am missing? I read in the original post that a bypass cable was used. Is there a lock on my tire size that won't allow it to change and need the bypass cable to go around it?

 

[LaramieEco95]

No need for bypass harness only 18 and newer

Sent from my GM1915 using

I have a 2018 ram and tried to change the tire size not knowing anything about the bypass cable, is this why in the size change section it will not take the new size?

 

[LaramieEco95]

Quick write to help with this. However I bear no responsibility for any changes that you might not like. Only ones you do.

Start off with key in run.
Open app
Select dodge/ram button, Ram 1500 or 2500 From drop down, Body Computer, then body computer MY2013-2017
Connect then click on the icon at the bottom with the hood open
From the drop menu select "Program tire size"

Right above start on this page is a text box that allows you to input the tire circumference in mm or you can use the drop menu to select a preprogrammed size. (Best way to get your mm number is to measure mounted height and then do your conversion, always round up or down to a whole number. This might take a couple adjustments from that to get perfect at 60.)
View attachment 145954

Press start and it should take a couple seconds to complete.
Once done back out to main page.

Cycle the key, at this point you can get all kinds of lights on the dash, so then you need to do the abs module.

Now select dodge/ram button, Ram 1500 or 2500 From drop down, ABS, then ABS Ate/Continental
View attachment 145953


Connect then click on the icon at the bottom with the hood open
From the drop down select ABS iniatiliazation
View attachment 145952

Read the instructions

View attachment 145951

Go back to the drop down and select static ECU initialization
Press start and wait to complete
Click on the check engine icon and clear faults
Then cycle key
Click back on the car icon
Select clearing Rolls Information from drop down, then start
After complete clear faults in the Body control module and the engine.
Cycle key
Once complete start your ram and take it for a spin, and check speed vs a gps. If your still off you can redo the process and adjust as needed.

This was performed on a 2018 Ram 2500 with version 2.1.4.0 on a android with OBDlink MX and a bypass cable

If anybody has noticed any differences on their vehicles or has any input to edit this let me know.

This may have been asked before an I apologize if it has, but will the bypass cable you used work on a 2018 eco diesel 1500? I found the bypass cable online but it days its for the Cummins 6.7.

 

[LaramieEco95]

I have a 2018 ram and tried to change the tire size not knowing anything about the bypass cable, is this why in the size change section it will not take the new size?

I have an 18' ram so I ordered the bypass cable. Hoping that will help me. From all that I have been researching it should

 

[Zjenji]

Hoping someone can help with this. My screen shots were taken when NOT connected but I was connected when attempting all actions. It seems I had no issues changing tire size but when I go to clear the ABS faults I am not seeing an option for "ABS Ate/Continental"
View attachment 481240
The only option that really applies to my truck (ABS Bosch/Continental/Teves/TRW PowerNet MY2013+ Powernet) does not enable the Start button. The instructions seem to indicate that maybe I need to go thru a different procedure but obviously I am hesitant to do so as I am not looking for a disaster. Really, I'm wondering why I do not get the "ATE" option.
View attachment 481239

Any insight or help is greatly appreciated since my truck is now sitting in the garage with a bunch of fault codes. Thanks.

I’m having the exact same issue. Has anyone figured this out?

 

[hunterdan]

I just did 2 tire size changes yesterday morning, one on a 2017 and the other on my 2019 classic. I wrote down and printed instructions just to be sure I followed them to a t. My truck was off about 2.8%, 2 mph at 70. I added 2.8% to the oem setting and programmed it. Had zero faults pop up. When I went to do the initialization, it wouldn't give me that option, on either truck. Cleared rolls information. Cleared the faults on all modules, even tho it didn't have any. Settings took on both trucks, speedometers are both accurate. My tire size was 275/65/20, the other guy was 35/12.50 (set circumference at 2714).
Is it possible that if you change the settings, you may not need to do all the abs stuff? Fwiw, the truck seems to perform better, feels stronger off the line and the shudder I had on take off seems to be gone.

 

[secretoctopus]

I just did 2 tire size changes yesterday morning, one on a 2017 and the other on my 2019 classic. I wrote down and printed instructions just to be sure I followed them to a t. My truck was off about 2.8%, 2 mph at 70. I added 2.8% to the oem setting and programmed it. Had zero faults pop up. When I went to do the initialization, it wouldn't give me that option, on either truck. Cleared rolls information. Cleared the faults on all modules, even tho it didn't have any. Settings took on both trucks, speedometers are both accurate. My tire size was 275/65/20, the other guy was 35/12.50 (set circumference at 2714).
Is it possible that if you change the settings, you may not need to do all the abs stuff? Fwiw, the truck seems to perform better, feels stronger off the line and the shudder I had on take off seems to be gone.

I am about to dive into fixing the same ~2.8% disparity in my speedo going from 265 to 285 tires. You proposed an entirely different fix here, how is it working out for you a few weeks later?

 

[hunterdan]

I am about to dive into fixing the same ~2.8% disparity in my speedo going from 265 to 285 tires. You proposed an entirely different fix here, how is it working out for you a few weeks later?

Still no issues. Haven't compared the speedometer to GPS in a few weeks, but I have zero reason to believe it's off. Mileage seems a tad optimistic, but I haven't tried to do manual calculation to check it.

 

[ANUFSED]

Quick write to help with this. However I bear no responsibility for any changes that you might not like. Only ones you do.

Start off with key in run.
Open app
Select dodge/ram button, Ram 1500 or 2500 From drop down, Body Computer, then body computer MY2013-2017
Connect then click on the icon at the bottom with the hood open
From the drop menu select "Program tire size"

Right above start on this page is a text box that allows you to input the tire circumference in mm or you can use the drop menu to select a preprogrammed size. (Best way to get your mm number is to measure mounted height and then do your conversion, always round up or down to a whole number. This might take a couple adjustments from that to get perfect at 60.)
View attachment 145954

Press start and it should take a couple seconds to complete.
Once done back out to main page.

Cycle the key, at this point you can get all kinds of lights on the dash, so then you need to do the abs module.

Now select dodge/ram button, Ram 1500 or 2500 From drop down, ABS, then ABS Ate/Continental
View attachment 145953


Connect then click on the icon at the bottom with the hood open
From the drop down select ABS iniatiliazation
View attachment 145952

Read the instructions

View attachment 145951

Go back to the drop down and select static ECU initialization
Press start and wait to complete
Click on the check engine icon and clear faults
Then cycle key
Click back on the car icon
Select clearing Rolls Information from drop down, then start
After complete clear faults in the Body control module and the engine.
Cycle key
Once complete start your ram and take it for a spin, and check speed vs a gps. If your still off you can redo the process and adjust as needed.

This was performed on a 2018 Ram 2500 with version 2.1.4.0 on a android with OBDlink MX and a bypass cable

If anybody has noticed any differences on their vehicles or has any input to edit this let me know.

Worked out well. Thank you!

 

[TX_Storm_Wagon]

For those wondering about the greyed out "Start" button:

Follow the write up verbatim. You don't have to actually run the feature on the abs initialization drop down. Technically, I'm not even sure you have to click on the abs initialization option to do the procedure.

Following the procedure worked for me. The greyed out button threw me for a few minutes, but I just stepped back through the instructions, cleared the codes from abs, engine, and body, and everything worked perfectly.

A+ write-up