AlfaOBD

[Pearce]

Did you completely shave off the triangle/wedge piece off of the tab? Looks that way on the white connector but black looks to be in tact. Did you just use a razor blade and carefully trim away?

Would like mine to be temporary (only connected when I want to make changes). From reading these posts, seems this cable can be a PITA to remove because of these clips. But don't want to destroy my new cable by cutting it incorrectly.

Both are shaved off using the file on my Leatherman. I figured the friction fit would keep it temporarily snug.

 

[Clayinfl]

I clipped mine with small wire cutters. The fit is very tight, but comes out with a firm pull. I was very happy I cut it after reading the struggles some have had getting them out. Smart call on a temporary installation.

 

[CforHD]

Thanks for the trimming tips!

For proper tire sizing in AlphaOBD, I understand it's looking for a circumference in mm. But it seems there isn't a definitive way of calculating this. Going through these threads, I've seen the following methods (will use my Toyo AT III 35x12.5x18 at 36psi rear as example):

1) Utilize manufactures "actual size" (ex. 34.5") for diameter
2) Measure diameter, from floor, using a straight edge at the top of the tire (ex. 33.5")
3) Measure the radius, from floor, to center bore of the wheel (see pic) to account for tire deformity (ex. 16.25")
4) Measure circumference by measuring the distance between two marks on ground. For this, I found the center of the wheel hub and using a laser level, I marked a line (on painters tape) on the tire and ground for both front & rear. Rolled the truck 1 revolution until the line on the tire was perpendicular to the ground and marked another line on the ground using the laser. (ex. 104 13/16" front, 104 7/8" rear)
5) Roll-over and wrap a fabric tape measure around the tire (haven't tried this one)
6) Use one of the above to get close and then utilize phone GPS to dial it in by making small adjustments up or down.

* NOTE: above assumes you convert diameter/radius in inches to circumference in mm

My question is, which is the most accurate method and why? Below are some of my theories:

#1) I assume this value is derived at max inflation (80psi in my case) & no load. As such, I'd think this would be the least accurate.
#2) Because the tire isn't deformed at the top, it would give an inaccurate result.
#3) I'm inclined to think this is the most accurate method as it's a static measurement (nothing is moving) and takes into account your specific PSI & tire deformity.
#4) This should be fairly accurate if done properly. But given any sort of steering input, camber, etc. could throw this off over the course of 100+ inches of travel. I believe this is the reason for my discrepancy between the result I got from #3.
#5) Should be just as accurate as #3 assuming you can keep the tape directly in the center of the tire as you roll over it.
#6) Is phone GPS that accurate? ie. 1/4mi races folks use high-end devices to be accurate.

 

[Jimmy07]

Thanks for the trimming tips!

For proper tire sizing in AlphaOBD, I understand it's looking for a circumference in mm. But it seems there isn't a definitive way of calculating this. Going through these threads, I've seen the following methods (will use my Toyo AT III 35x12.5x18 at 36psi rear as example):

1) Utilize manufactures "actual size" (ex. 34.5") for diameter
2) Measure diameter, from floor, using a straight edge at the top of the tire (ex. 33.5")
3) Measure the radius, from floor, to center bore of the wheel (see pic) to account for tire deformity (ex. 16.25")
4) Measure circumference by measuring the distance between two marks on ground. For this, I found the center of the wheel hub and using a laser level, I marked a line (on painters tape) on the tire and ground for both front & rear. Rolled the truck 1 revolution until the line on the tire was perpendicular to the ground and marked another line on the ground using the laser. (ex. 104 13/16" front, 104 7/8" rear)
5) Roll-over and wrap a fabric tape measure around the tire (haven't tried this one)
6) Use one of the above to get close and then utilize phone GPS to dial it in by making small adjustments up or down.

* NOTE: above assumes you convert diameter/radius in inches to circumference in mm

My question is, which is the most accurate method and why? Below are some of my theories:

#1) I assume this value is derived at max inflation (80psi in my case) & no load. As such, I'd think this would be the least accurate.
#2) Because the tire isn't deformed at the top, it would give an inaccurate result.
#3) I'm inclined to think this is the most accurate method as it's a static measurement (nothing is moving) and takes into account your specific PSI & tire deformity.
#4) This should be fairly accurate if done properly. But given any sort of steering input, camber, etc. could throw this off over the course of 100+ inches of travel. I believe this is the reason for my discrepancy between the result I got from #3.
#5) Should be just as accurate as #3 assuming you can keep the tape directly in the center of the tire as you roll over it.
#6) Is phone GPS that accurate? ie. 1/4mi races folks use high-end devices to be accurate.

#3 is going to be the most accurate, then do #6.

 

[Brutal_HO]

#3 is going to be the most accurate, then do #6.

#3 is static and is going to change ever so slightly under dynamic rolling and load conditions so #6 is a validation of an average over time/distance.

When doing #6, make sure you're reading the phone GPS speed and not AA or Carplay connected/plugged in speed that may be displayed on your phone app but based on the truck's NAV.

 

[CforHD]

#3 is going to be the most accurate, then do #6.

Thanks. You think phone GPS is more accurate to dial-in your measurement? Or do you suggest just using it as a sanity check? ie. If I see a 1-2mph difference, stick with measured value?

I see that the default value is set to 32.25” diameter. This is odd to me given my 35's measure out to just 0.25” (32.5") more. Perhaps this is just due to much lower PSI needed for the Toyos?

 

[AH64ID]

Many manufacturers publish rev/mile data, and that is the best starting point and also the easiest to obtain.

I’ve used that data on multiple trucks and tires. It always gets me close.

Factory data on the 285/60R20’s was pretty far off, but otherwise it works.

 

[Diputs]

I can't get alfaobd to update settings in the body computer. I pull up the setting I want to change hit start. Then next. And nothing happens. The button changes back to start. I tried cycling the ignition and waiting a few min before checking again.

 

[Jimmy07]

I can't get alfaobd to update settings in the body computer. I pull up the setting I want to change hit start. Then next. And nothing happens. The button changes back to start. I tried cycling the ignition and waiting a few min before checking again.

You have the bypass harness installed?

 

[Diputs]

You have the bypass harness installed?

Yea. But I guess it would help if I plugged the obdlink into it instead of the regular obd port.. got it to work now.. thanks Jimmy

 

[Jimmy07]

Yea. It worked when I changed to the power fold mirrors. The screen shots are what happens. Hit start, goes to the screen telling me to hit next, then shows start again.

Might have to send a debug log to the developer. Does it do that with any setting?

 

[Diputs]

Might have to send a debug log to the developer. Does it do that with any setting?

It was my fault.. plugged the obdlink into the oem plug not the bypass. Got it to work.

 

[Ostracize]

@Jimmy07... Or anyone else. I have a 2021 3500 Limited with leveling springs... Obviously once leveled the surround view front camera vs the LH/RH cameras are misaligned. I have a bypass cable (not installed yet) and a OBDLinkMX+. Not purchased alfaobd yet but no issues in doing so. Can I recalibrate the surround view cams to be accurate with leveled front? If so, how? Appreciate your time.

 

[jsalbre]

@Jimmy07... Or anyone else. I have a 2021 3500 Limited with leveling springs... Obviously once leveled the surround view front camera vs the LH/RH cameras are misaligned. I have a bypass cable (not installed yet) and a OBDLinkMX+. Not purchased alfaobd yet but no issues in doing so. Can I recalibrate the surround view cams to be accurate with leveled front? If so, how? Appreciate your time.

The cameras are attached to the body and don’t change position relative to each other when you level the truck. There shouldn’t be anything to recalibrate.

 

[Ostracize]

The cameras are attached to the body and don’t change position relative to each other when you level the truck. There shouldn’t be anything to recalibrate.

I realize they don't magically change from their fixed mounting positions... But when that position is now ~higher what they see in relationship to each other does change.
The cvpm has a calibration from my understanding... This would indicate that it has to calibrate how the surround view camera images are "stitched" together.
... And since now the hight and angle relationships to each other has changed due to leveling, the stitching is off/inaccurate.
So back to my original question asking if someone has actually completed the process of calibration and maybe can share some info on how/best techniques.

 

[AH64ID]

K

I realize they don't magically change from their fixed mounting positions... But when that position is now ~higher what they see in relationship to each other does change.
The cvpm has a calibration from my understanding... This would indicate that it has to calibrate how the surround view camera images are "stitched" together.
... And since now the hight and angle relationships to each other has changed due to leveling, the stitching is off/inaccurate.
So back to my original question asking if someone has actually completed the process of calibration and maybe can share some info on how/best techniques.

If they are in the same physical location to each other then the stitching isn't effected.

 

[Ostracize]

K


If they are in the same physical location to each other then the stitching isn't effected.

Gents,
Leveled, not lifted. The front camera is now.. let's say 2in higher, and the LH / RH cameras are only .5in-1in higher. Let's set aside the fact that I can literally see the difference in the image(s) now... Your comment stating there's no reason for calibration to my original ask to the hive mind for others' experience with alfaobd / how to trigger a cal / where it's best to complete said cal doesn't contribute anything. So although I appreciate almost all feedback on this forum, what I would like is an answer to my original question (please) and to not be derailed by your opinion.

 

[AH64ID]

Gents,
Leveled, not lifted. The front camera is now.. let's say 2in higher, and the LH / RH cameras are only .5in-1in higher. Let's set aside the fact that I can literally see the difference in the image(s) now... Your comment stating there's no reason for calibration to my original ask to the hive mind for others' experience with alfaobd / how to trigger a cal / where it's best to complete said cal doesn't contribute anything. So although I appreciate almost all feedback on this forum, what I would like is an answer to my original question (please) and to not be derailed by your opinion.

The only thing I've seen in the past is that there is no way to calibrate the cameras, with AlfaOBD or at the dealership.

But lets be honest, what do you think happens when you load the truck with 2K of tongue weight? The same aspect ratio changes and that doesn't effect the camera stitching at all. If you can see an error in your stitching then it was there before, the cameras only care about their relationship to each other not their proximity to the ground.

 

[CdnHO]

The only thing I've seen in the past is that there is no way to calibrate the cameras, with AlfaOBD or at the dealership.

But lets be honest, what do you think happens when you load the truck with 2K of tongue weight? The same aspect ratio changes and that doesn't effect the camera stitching at all. If you can see an error in your stitching then it was there before, the cameras only care about their relationship to each other not their proximity to the ground.

I agree, changing the suspension does not change the relationship between the cameras and body.

 

[Ostracize]

This post...

I got impatient and tried to force recalibrate the whole system. It did the surround view just fine, still no joy on the CHMSL. Let me know when you hear back on the Debug log. Thanks.

Way back in this thread is what I'm going off of, which seems to show that it's indeed possible unless I'm misunderstanding something in context, but I can't find anything more which is why am asking.