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 Post subject: I think I can change tire size w/o starscan. Need more info.
PostPosted: Thu Sep 26, 2013 5:39 pm 
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I've been playing around with a OBD bluetooth adapter trying to see what we can do without a starscan, namely trying to change tire sizes.

I think I've found the ABS module at address 0x784 and the tire size using command 21 60. If those of you with a OBD/CAN reader can send 21 60 to the ABS module and let me know what you get back as well as your stock or reprogrammed tire size, I would appreciate it. You should get back 61 60 XX YY where XXYY is your tire circumference in mm.

I got back 08F0, which works out to 2288mm with 225/75/16, which is smaller than it is supposed to be and want to see if it changes depending on tire size.

Once I get enough data to see if this is the right location, I can try to write to it with an updated circumference. If anyone is interested in my methods, let me know and I'll tell you how I found everything out so far.

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245/75/16 Nokian Rotiiva AT Plus
Numerous junkyard upgrades


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 Post subject: Re: I think I can change tire size w/o starscan. Need more i
PostPosted: Sat Sep 28, 2013 6:27 am 
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ajohns1288 wrote:
I've been playing around with a OBD bluetooth adapter trying to see what we can do without a starscan, namely trying to change tire sizes.

I think I've found the ABS module at address 0x784 and the tire size using command 21 60. If those of you with a OBD/CAN reader can send 21 60 to the ABS module and let me know what you get back as well as your stock or reprogrammed tire size, I would appreciate it. You should get back 61 60 XX YY where XXYY is your tire circumference in mm.

I got back 08F0, which works out to 2288mm with 225/75/16, which is smaller than it is supposed to be and want to see if it changes depending on tire size.

Once I get enough data to see if this is the right location, I can try to write to it with an updated circumference. If anyone is interested in my methods, let me know and I'll tell you how I found everything out so far.


I'm curious but I probably wouldn't understand :dizzy: You could give it a shot though :)

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2010 KK Deep Water Blue,OME Liftplus 1",JBA 5.5 UCA ,Dynaflow cat back exhaust, Weathertech VV & mats,Mopar skids,Atthehelm front bumper, Smittybilt XRC 10, Rigid LED's,RL Skink Supersliders,Gecko Safari Basket Detroit Truetrac rear, E-Locker front, G2, Dana 4.10's


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 Post subject: Re: I think I can change tire size w/o starscan. Need more i
PostPosted: Sat Sep 28, 2013 6:27 am 
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Joined: Thu Aug 11, 2011 2:17 pm
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Location: Akron, Ohio
ajohns1288 wrote:
I've been playing around with a OBD bluetooth adapter trying to see what we can do without a starscan, namely trying to change tire sizes.

I think I've found the ABS module at address 0x784 and the tire size using command 21 60. If those of you with a OBD/CAN reader can send 21 60 to the ABS module and let me know what you get back as well as your stock or reprogrammed tire size, I would appreciate it. You should get back 61 60 XX YY where XXYY is your tire circumference in mm.

I got back 08F0, which works out to 2288mm with 225/75/16, which is smaller than it is supposed to be and want to see if it changes depending on tire size.

Once I get enough data to see if this is the right location, I can try to write to it with an updated circumference. If anyone is interested in my methods, let me know and I'll tell you how I found everything out so far.


I'm curious but I probably wouldn't understand :dizzy: You could give it a shot though :)

_________________
2010 KK Deep Water Blue,OME Liftplus 1",JBA 5.5 UCA ,Dynaflow cat back exhaust, Weathertech VV & mats,Mopar skids,Atthehelm front bumper, Smittybilt XRC 10, Rigid LED's,RL Skink Supersliders,Gecko Safari Basket Detroit Truetrac rear, E-Locker front, G2, Dana 4.10's


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 Post subject: Re: I think I can change tire size w/o starscan. Need more i
PostPosted: Sun Sep 29, 2013 3:44 am 
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I'd be interested on what you have so far. Post it here or PM me. :D

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 Post subject: Re: I think I can change tire size w/o starscan. Need more i
PostPosted: Sun Sep 29, 2013 3:49 pm 
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Scar0 wrote:
I'd be interested on what you have so far. Post it here or PM me. :D


What I basically did was purposely set some fault codes that are only visible to specific modules (Airbag, ABS, etc) so I could see which address went to which module. When I found the ABS module, I scanned for mode $21 pids and searched the data for any numbers that were close to a standard tire radius/diameter/circumference. Once I had that list, I scanned a few more times to see what stayed the same. The only one I found that met all that criteria was $21 $60. Once I get new tires, I plan on trying to change this value after a test drive and compare GPS to reported speed. If I see it make a difference, I'll know for sure. Down below is a list of CAN adresses and their modules I have found so far. I'm not 100% sure on the cluster one though.

Code:
ECU   Send To   Receive from
Cluster?   514   6A0
ABS   785   784
PCM   7E8   7E0
ORC   51C   6E0
WCM   500   600
TIPM 620 504



I am also in the middle of making a quick program to scan for DTCs in those listed modules. All you have to do is send 1800FF00 to each of those addresses and they should respond with any fault codes.

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2008 Liberty Sport
OME Lift, JBA A-Arms + Track Bar
245/75/16 Nokian Rotiiva AT Plus
Numerous junkyard upgrades


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