37" Tire Owners - have a question

[ljn21]

We reprogram the speedometer to reflect accurate speeds. I'm not sure on the process they use for parking sensors.

Any updates here Zach, can you find out more about how the speedometer recalibration works, what tool/platform is used to do it, etc?

 

[Elarson6772]

I use Hypertech in line calibrator which works to correct the speedo but it cheats by intercepting and altering the signal right behind the cluster. As a result as an example, your speedo is accurate but when you set the cruise, your cruise speed will still be wrong.

Other than that issue it works perfectly.

 

[ljn21]

I saw on the regular 1500 forum that someone set their tire size using AlfaOBD to “auto” and they swap back and forth between 33” and 35” tires and claim their Speedo automatically adjust, they supposedly confirmed with a separate GPS. Sounds to good to be true but wondering if anyone with AlfaOBD could try that to see if that option is there and if it works? Maybe that’s a way around the parking sensors getting turned off.

 

[Zach@Granger]

Any updates here Zach, can you find out more about how the speedometer recalibration works, what tool/platform is used to do it, etc?

Yes, sorry for the delay. We used the HP tuner tool and we found the speedometer is correct with an input of 36.5" tires (actualy measured size). The parking sensors all work properly as well.

 

[Elarson6772]

Yes, sorry for the delay. We used the HP tuner tool and we found the speedometer is correct with an input of 36.5" tires (actualy measured size). The parking sensors all work properly as well.

Interesting. The only explanation for this is at some point the trucks coming out more recently got a software fix for this.

 

[ljn21]

Yes, sorry for the delay. We used the HP tuner tool and we found the speedometer is correct with an input of 36.5" tires (actualy measured size). The parking sensors all work properly as well.

Thanks!

 

[ljn21]

Yes, sorry for the delay. We used the HP tuner tool and we found the speedometer is correct with an input of 36.5" tires (actualy measured size). The parking sensors all work properly as well.

Hi again Zach, just to confirm, you are changing the tire size in HPT and not axle gear ratio? Could you confirm that with the tech that does the tuning?

I’m not to familiar with HPT and I asked a local tuner who uses it on Raptors, GT500s, etc and when I asked him about how to use HPT to change tire size, he said he could only do it via changing the axle ratio. Could you confirm you guys are actually able to change tire size and not axle ratio?

Any chance of getting step by step instructions how to use HPT to update it if it’s really changing tire size?

 

[Zach@Granger]

Hi again Zach, just to confirm, you are changing the tire size in HPT and not axle gear ratio? Could you confirm that with the tech that does the tuning?

I’m not to familiar with HPT and I asked a local tuner who uses it on Raptors, GT500s, etc and when I asked him about how to use HPT to change tire size, he said he could only do it via changing the axle ratio. Could you confirm you guys are actually able to change tire size and not axle ratio?

Any chance of getting step by step instructions how to use HPT to update it if it’s really changing tire size?

We've actually had some issues with this that I wasn't initially made aware of. After a little while driving and key cycles the park sensors become made unavailable like the other customers are having.

We are able to adjust tire size specifically. We have a HP Tuner tuning tool, which may be different than what you are using.

 

[jqram25]

I use Hypertech in line calibrator which works to correct the speedo but it cheats by intercepting and altering the signal right behind the cluster. As a result as an example, your speedo is accurate but when you set the cruise, your cruise speed will still be wrong.

Other than that issue it works perfectly.

So you have to adjust CC down to compensate for the error then?

 

[Elarson6772]

So you have to adjust CC down to compensate for the error then?

No you set your cruise based on the speed you are going as normal. Just the little symbol on the dash that shows the speed the cruise is set at will still reflect the incorrect speed. As an example when I set my cruise on the highway for 70, the little cruise symbol shows I have it set at 67mph.

The in-line calibrator only corrects the speedometer.

 

[Red Dot v2]

I run a 37inch tire on 22s. Has anyone gotten this message before? Wonder if it’s the sensors or speedo that is causing this to pop up. It goes away after 2-3 seconds.

 

[Elarson6772]

I run a 37inch tire on 22s. Has anyone gotten this message before? Wonder if it’s the sensors or speedo that is causing this to pop up. It goes away after 2-3 seconds.

No, neither of those items. It’s a very common problem on all the latest Ram 1500’s.

Do you have the trailer steer option? Looks like there is a bulletin out for this and it’s directly related to the trailer steering system trying to calibrate when there isn’t a trailer connected. Looks like there is no fix right now for that and it will be handled in a future UConnect update according to my dealer.

 

[HYDROREX]

I run a 37inch tire on 22s. Has anyone gotten this message before? Wonder if it’s the sensors or speedo that is causing this to pop up. It goes away after 2-3 seconds.

I'm stock height and stock wheels and tires. I too have been getting it since I got the truck. It comes on every time I drive it after about 2 minutes. Dealership has no clue...

 

[Dudebro]

Do you have trailer steer assist or whatever it is called? Looks like it's a common issue on Ram 1500's with that option and that needs to be recalibrated.

 

[HYDROREX]

Do you have trailer steer assist or whatever it is called? Looks like it's a common issue on Ram 1500's with that option and that needs to be recalibrated.

I do... I'm going to let my dealership know that there is a TSB out for it.

 

[Red Dot v2]

No, neither of those items. It’s a very common problem on all the latest Ram 1500’s.

Do you have the trailer steer option? Looks like there is a bulletin out for this and it’s directly related to the trailer steering system trying to calibrate when there isn’t a trailer connected. Looks like there is no fix right now for that and it will be handled in a future UConnect update according to my dealer.

Yes I have the reverse trailer steering. Thank you everyone for letting me know! I’ll be on the lookout to when a fix comes available. Glad it wasn’t something too terribly bad.

 

[Mikey DownUnder]

Hi everyone. I have a '22 TRX and have just upgraded to 37" Kenda Klever R/T tyres (Nitto's are impossible to get over here). I measured the diameter of the tyre whilst it was lying on the ground and it came to 36.2992 inches. I programmed the Tazer to the 36.31 inches setting and my parking sensors switched off. I also tried it at a slightly lower setting, but they were still off. Just letting people know that they switch off under 36.5

 

[Elarson6772]

Hi everyone. I have a '22 TRX and have just upgraded to 37" Kenda Klever R/T tyres (Nitto's are impossible to get over here). I measured the diameter of the tyre whilst it was lying on the ground and it came to 36.2992 inches. I programmed the Tazer to the 36.31 inches setting and my parking sensors switched off. I also tried it at a slightly lower setting, but they were still off. Just letting people know that they switch off under 36.5

Yep it’s a known issue. They fault out actually when you adjust just over 35” or more.

 

[Cmw1100]

Gave up on Tazer.
Running 37” Nitto ridge Grapplers on stock 18” wheels. I have learnt to live with the speedometer to actual speed difference.
4km/h difference for me.
More disappointed that Mopar beadlocks on my 37”s with stock wheel - there is a slight leak

 

[JBTRXNJ]

Gave up on Tazer.
Running 37” Nitto ridge Grapplers on stock 18” wheels. I have learnt to live with the speedometer to actual speed difference.
4km/h difference for me.
More disappointed that Mopar beadlocks on my 37”s with stock wheel - there is a slight leak

Beadlock Ring, or Dress Ring?