TPMS Setting with a Tuner

[Snekpete]

Okay, I've done some searches and such and keep getting a LOT of disjointed information. It appears that we are losing our ability to clearly convey simple information.

The problem: I have set the tire pressures to 45/35. This causes the TPMS warning on the console. This is a 2021 RAM Rebel.

The solution: AlphaOBD to set the TPMS pressures.

The questions: AlphaOBD is a software program developed for FCA vehicles. It can be installed on a Windows PC or an Android phone. It appears that it would be easier to use on a phone or a tablet, and I don't have a tablet so phone it is.

1) I purchase and install AlphaOBD on my phone.
2) I will need a compatible OBD interface to plug into the OBD port. Any current recommendations?
3) Will I also need a hardware SGW bypass module? If so which one, what model, where to purchase?

 

[Snekpete]

After studying the AlfaOBD website:

1) AlfaOBD from manufacturer $56.70 Actual $49.00 + tax.
2) OBDLINK® MX+ $139 on Amazon.
3) Yes. KaodTECH from manufacturer $55.

Total ≈ $250.00

Will this allow me to reset the TPMS warning? Unknown, but worth a try.

 

[Snekpete]

12/01/2022



Got the OBD Link yesterday, gotta love Amazon!

There was no problem connecting the link to the truck OBD Port and then connecting via Bluetooth to the phone. Opened the AlfaOBD app and successfully interfaced to the OBD Link.

I could connect to the Instrument Panel and a couple of other functions but not to the "Tire Control". Will need the SGW Bypass I suspect. That cable hasn't shipped yet. Once I can connect to the Tire Control then the million dollar question: Will the app allow modifications?

 

[Idahoktm]

Wow, that's way too expensive. Here are the two I bought.

https://www.amazon.com/gp/product/B005NLQAHS/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&th=1

ECRI Security Gateway Module Bypass (Fits 2018+ Jeep, Ram, Chrysler, Alfa Romeo, Fiat) * NO RETURNS *

NO RETURNS - Due to excessive abuse by customers returning this item after use, we no longer accept returns of SGW bypass orders. Chrysler has introduced a Security Gateway Module (SGW/SGM), which blocks aftermarket programming from writing to your ECU. This bypass allows ECRI to calibrate your...

ecri.app

Yes, you will need the security bypass and then you will be able to change the tire pressure thresholds.

 

[HSKR R/T]

For what you spent on alfaOBD just to change tire pressure setting, could have spent a little more, got a Tazerdt, had the same ability, plus a lot of other features not available with alfaObd. Plus it's an easier interface, and less chance of bricking your BCM changing the wrong setting

 

[Snekpete]

I'm pretty sure that the Tazer DT and the alfaOBD provide similar functionality. Cheaper OBD links are available, I just wanted to make sure that they are compatible with alfaOBD. The OBDLink is overkill, but it also a really nice link that works perfectly. Disabling the SGW is the trickiest part, I liked the idea of a cable that temporarily bypasses it.

The BAFX Reader and ECRI bypass look like they will indeed work at a far lower price point.

But anyway, that's the point of this thread, to document and simplify what seems to me to be an overly complicated topic.

 

[HSKR R/T]

View attachment 145029

I'm pretty sure that the Tazer DT and the alfaOBD provide similar functionality. Cheaper OBD links are available, I just wanted to make sure that they are compatible with alfaOBD. The OBDLink is overkill, but it also a really nice link that works perfectly. Disabling the SGW is the trickiest part, I liked the idea of a cable that temporarily bypasses it.

The BAFX Reader and ECRI bypass look like they will indeed work at a far lower price point.

But anyway, that's the point of this thread, to document and simplify what seems to me to be an overly complicated topic.

The TazerDT live functions are the things that alfaOBD can't do. things like light show, disable traction control, nav in motion,...... Granted there are settings that you can change with alfaObd that they haven't programmed the TazerDT for yet, but it's just a matter of the programmers for Z-Automotive to write the code.

 

[Jimmy07]

I could connect to the Instrument Panel and a couple of other functions but not to the "Tire Control". Will need the SGW Bypass I suspect. That cable hasn't shipped yet. Once I can connect to the Tire Control then the million dollar question: Will the app allow modifications?

You couldn’t connect to the tire control module because the truck doesn’t have one.
All configuration changes, including the tire pressure thresholds, are done in the body control module.
You can connect to, and read info from any module without a security gateway bypass, but in order to send any commands or make changes, you need a bypass installed.

To change the tire pressure thresholds, connect to the body computer, go into car configuration change, and find these two:
VehConfig 2: Max Load Inflation Pressure Rear Tire (0-126PSI)- enter psi value
VehConfig 2: Max Load Inflation Pressure Front Tire (0-126PSI)- enter psi value

 

[Snekpete]

You couldn’t connect to the tire control module because the truck doesn’t have one.
All configuration changes, including the tire pressure thresholds, are done in the body control module.
You can connect to, and read info from any module without a security gateway bypass, but in order to send any commands or make changes, you need a bypass installed.

To change the tire pressure thresholds, connect to the body computer, go into car configuration change, and find these two:
VehConfig 2: Max Load Inflation Pressure Rear Tire (0-126PSI)- enter psi value
VehConfig 2: Max Load Inflation Pressure Front Tire (0-126PSI)- enter psi value

Thanks!

≈10:00 am
Got into the Body Computer, there were 15 different Select Control Unit choices for the Body computer, I picked the first one and it seems to default to "Body computer MY2021 PowerNet"

From there I can select "set Procedure to Start". Then "Update Pressure Thresholds". "Status Pressure Rear" and "Status Pressure Front". Of course it will not take until I get the SGW bypass.

I did a backup of the original config, but I do not know where AlfaOBD stored the backup on my phone. I may have to actually read the instructions, no, that's too much trouble.

In summary:

1) Insert the OBDLink and turn the truck to run without starting
2) Open AlfaOBD on the phone and select BlueTooth and then select OBDLINK MX+
3) Select RAM 1500 (DS/DX/DT)
4) Select Body Computer
5) Select Body computer MY2021 PowerNet
6) set Procedure to Start->Update Pressure Thresholds->Status Pressure Rear and then Status Pressure Front

Almost there, this looks like it might actually work. There are a s load of different computers each with a s load of settings for each. Yes, you could probably seriously f up this truck, but all that I want to do is turn off the idiotic TPMS warning that tells me that I've set my tires to a "normal", non-CAFE setting.

≈11:00 am

To change the tire pressure thresholds, connect to the body computer, go into car configuration change, and find these two:
VehConfig 2: Max Load Inflation Pressure Rear Tire (0-126PSI)- enter psi value
VehConfig 2: Max Load Inflation Pressure Front Tire (0-126PSI)- enter psi value

I did see those the first time around, now I can't find them, just the Update Pressure Thresholds.

≈12:00 pm
Okay, found it:

1) Insert the OBDLink and turn the truck to run without starting
2) Open AlfaOBD on the phone and select BlueTooth and then select OBDLINK MX+
3) Select RAM 1500 (DS/DX/DT)
4) Select Body Computer
5) Select Body computer MY2021 PowerNet
6) Select Connect
7) set Procedure to Start->car configuration change->car configuration change and VehConfig 2: Max Load Inflation Pressure Front Tire (0-126PSI)- enter psi value

Man, I'd still be looking for those next year if I didn't have some help. I wonder if there's a difference between Max Load Inflation and Update Pressure Thresholds->Status Pressure ?

After I do this a few hundred more times I might get good at it.

 

[Snekpete]

I was able to set both the Max Load Inflation Pressure and Update Pressure Thresholds. I am not sure which does what. Anyway I set them both to 45 front, 40 rear. They took but I still get the warning. I have read that I do not need to recycle the RF interface so I am not sure why I am still getting the warning. I am going to drive the truck for a few days and see if the warning goes away.





BTW, all the complaints about jerky braking, rough shifting from a stop, when the Auto Start/Stop kicks in and LOTS MORE, are all settable via the Body Control Module. A RAM mechanic that's worth anything should be able to get in and adjust these parameters to suit the individual truck, conditions and driver.

 

[Jimmy07]

I was able to set both the Max Load Inflation Pressure and Update Pressure Thresholds. I am not sure which does what. Anyway I set them both to 45 front, 40 rear. They took but I still get the warning. I have read that I do not need to recycle the RF interface so I am not sure why I am still getting the warning. I am going to drive the truck for a few days and see if the warning goes away.

View attachment 145326 View attachment 145325



BTW, all the complaints about jerky braking, rough shifting from a stop, when the Auto Start/Stop kicks in and LOTS MORE, are all settable via the Body Control Module. A RAM mechanic that's worth anything should be able to get in and adjust these parameters to suit the individual truck, conditions and driver.

Inflate the rears to 40 like it says, and the warning will go out. Then you can drop back down to 37 with no warnings.

 

[Jimmy07]

The “update pressure thresholds” is a shortcut function of the two VehConfig 2 settings, I just always forget it’s there.

 

[Snekpete]

The “update pressure thresholds” is a shortcut function of the two VehConfig 2 settings, I just always forget it’s there.

Okay, so you're saying that they're the same.



That explains it, I think. I either have to inflate the rears to 40 or above or wait up to 20 minutes above 15 mph for the tpms to receive new information, maybe both.

Man, these vehicles are getting complex. I'll bet there aren't two RAM mechanics East of the Mississippi that can properly set and adjust any of the BCM options.

 

[SD Rebel]

Inflate the rears to 40 like it says, and the warning will go out. Then you can drop back down to 37 with no warnings.

Correct. Once you get a warning, it won't go away until you reach the exact recommend pressure. After you hit that pressure and the warning comes off, you can then drop down a few psi without getting a warning.

But once you get a warning, you have to go all the way back up for it to turn off.

 

[Snekpete]

Correct. Once you get a warning, it won't go away until you reach the exact recommend pressure. After you hit that pressure and the warning comes off, you can then drop down a few psi without getting a warning.

But once you get a warning, you have to go all the way back up for it to turn off.

Seems reasonable, that's why I chose 40psi for the rears. The warning will go off when the tires are ≈ 20% low (or high?). 20% of 40 is 8 and I'd like to know if the tires are below 32psi. I am setting the tires at 45/35 for now, the TPMS sensors are almost always off by a few psi.

 

[rossvdm3]

Seems reasonable, that's why I chose 40psi for the rears. The warning will go off when the tires are ≈ 20% low (or high?). 20% of 40 is 8 and I'd like to know if the tires are below 32psi. I am setting the tires at 45/35 for now, the TPMS sensors are almost always off by a few psi.

Did this end up working? I am about to do the same thing if it worked for you.

 

[Snekpete]

Yes, it worked perfectly.

 

[Rampat]

I just updated my tires and TPMS using JSCAN and OBDMX+. Speedo is dead on using 34.5” and set the front TPMS to 50 and rear to 40. Toyo recommended I run the front at 49psi and rear at 37psi.