Issues with AlfaOBD and changing tire size

[CanRebel]

Not sure if this will help or not, as I have 5th Gen.

I changed the rim and tires on my Rebel. Every tire website gave me same number. When I would enter it, I would get crazy codes, half the truck was disabled.

So I put back original number. And then slowly increased the number manually, until it would throw codes, then backed it up one. It's technically off by 1-2 on speed, but close enough that I don't care.

 

[RamDiver]

So I've only done the tire change procedure to it. Went into BCM and ran that procedure, disconnected, cycled key off waited a minute, turned it back to run. Then connected into ABS and did ECU initialization, cleared CELs, disconnected, cycled off and back to run, then did clearing rolls information, cleared CELs in ABS, BCM, then PCM. All standard procedure we've done before. When turned on power steering was locked up and multiple CELs for implausible data. Repeated for multiple types of common values including the stock option in the drop-down which is the Goodyear Wrangler SR-A 275/60r20 which set the value of 2750mm. It didn't like it, same results. Went to my truck and pulled the value on mine and my truck said 65535mm and used that value into his so it could be drivable again but off by 4 again. 65535mm (max value according to AlfaOBD is 65534mm) sounds outrageous and never showed that before on either truck.

OK, thanks for those details.

It appears as though you've followed the procedure correctly, as far as I can see. Hopefully, someone with more experience using AlphaOBD will see any possible errors in the procedure or have recommendations on what to try next.

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[Dean2]

I would contact Alexey the developer and get some help. Something isn't right but I can't tell what is off.

 

[John Jensen]

They say on the newer trucks you don't need to do an ABS Initialization. I have a hunch that in some cases where there's a problem with the tire size change not taking effect, maybe the ABS does need Initializing. Here is an older link that does a good job of describing the process. Maybe it will help
Tire size change and ABS Initialization

 

[AEDELGOD]

They say on the newer trucks you don't need to do an ABS Initialization. I have a hunch that in some cases where there's a problem with the tire size change not taking effect, maybe the ABS does need Initializing. Here is an older link that does a good job of describing the process. Maybe it will help
Tire size change and ABS Initialization

ABS initialization is greyed out for us. He has a 2015 Sport and I have a 2014 Lone Star. Doesn't let us select start on that menu. It's definitely taking our changes though.

The issue that is racking my brain is I've never done this procedure before on my own truck and I have stock 20" wheels and it I checked what mine are set at and AlfaOBD is saying it is 65535mm, which that can't be right.

As a hail mary we set my friends truck to that and now it's drivable but off by 4 and he texted me this morning saying his steering isn't quite right still.

I've emailed Alexey from AlfaOBD and we've emailed back and forth a little bit not much from him yet, just answering all his questions.

 

[RamDiver]

ABS initialization is greyed out for us. He has a 2015 Sport and I have a 2014 Lone Star. Doesn't let us select start on that menu. It's definitely taking our changes though.

The issue that is racking my brain is I've never done this procedure before on my own truck and I have stock 20" wheels and it I checked what mine are set at and AlfaOBD is saying it is 65535mm, which that can't be right.

As a hail mary we set my friends truck to that and now it's drivable but off by 4 and he texted me this morning saying his steering isn't quite right still.

I've emailed Alexey from AlfaOBD and we've emailed back and forth a little bit not much from him yet, just answering all his questions.

Please keep us posted on any new developments.

.

 

[SitKneelBend]

ABS initialization is greyed out for us. He has a 2015 Sport and I have a 2014 Lone Star. Doesn't let us select start on that menu. It's definitely taking our changes though.

The issue that is racking my brain is I've never done this procedure before on my own truck and I have stock 20" wheels and it I checked what mine are set at and AlfaOBD is saying it is 65535mm, which that can't be right.

As a hail mary we set my friends truck to that and now it's drivable but off by 4 and he texted me this morning saying his steering isn't quite right still.

I've emailed Alexey from AlfaOBD and we've emailed back and forth a little bit not much from him yet, just answering all his questions.

Did you happen to upgrade your phone recently? If so, you old phone (if available) might have an older version of the app to try? Just don't let it update when you fire it up.

 

[AEDELGOD]

Please keep us posted on any new developments.

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Preliminary, it appears to be a read/display bug with the app not giving the correct/current value. I've reported my findings to Alexey just now. I was able to correct my friends truck but I had to put my programmer hat on and really critically think through how the software code is likely working, so I was working blind but got it all in good working order and being off about 1mph on the speedometer.

Did you happen to upgrade your phone recently? If so, you old phone (if available) might have an older version of the app to try? Just don't let it update when you fire it up.

I wish, I was about to start looking for older versions of the APK but Alexey hasn't been very responsive during all this.

 

[SitKneelBend]

Preliminary, it appears to be a read/display bug with the app not giving the correct/current value. I've reported my findings to Alexey just now. I was able to correct my friends truck but I had to put my programmer hat on and really critically think through how the software code is likely working, so I was working blind but got it all in good working order and being off about 1mph on the speedometer.

I wish, I was about to start looking for older versions of the APK but Alexey hasn't been very responsive during all this.

I looked too but it doesn't appear those are published anywhere. From my understanding, Alexei can get busy but once he does respond he's very responsive. If I find an installable APK I'll let you know.

 

[Big3MG]

You would take the tire off and measure the diameter with a tape measure and convert inches to mm. But always check with Waze as this GPS app shows actual speed. Then go back and tweak it. Google can tell you how many inches or mm to increase or decrease based on mph displayed vs actual. It never works using some factory tire size / diam.