Disconnecting battery deleted custom TPMS setting?

[Dean2]

Glad it all worked out and turned put to be nothing more than a bad sensor like I suspected. Since you have alpha, you can set lower tpms thresholds if you want to. You can set whatever limit you like and it won't alert till it drops 20% below what you set.

Thanks for taking the time to do the detailed updates. I am sure many will have learned a lot from it.

 

[Jebb]

OK, new sensor came in yesterday. Went into AlfaOBD and reset car config to "Full Size Spare Present : YES". Went to RF Hub and reset. Powered off truck and turned on ignition. TPMS light back on.

Broke spare tire down and installed new sensor. Programmed sensor with TPMS tool and updated the truck with the tool through the OBD port.

Reset the RF Hub again, since there is a new sensor.

Voila, the light is now gone.

Let air out of spare and it DID NOT set off the light. Removed spare from truck and moved spare way out of garage. Tuned ignition on, now TPMS light blinks for 75 seconds (searching for the spare sensor). TPMS light goes on solid after the 75 seconds. Remounted spare in truck and verified 39 PSI air and TPMS light is now off.

All is good now and works as manual showed.

Still confused by your story. If all is working properly - and it's reading the spare - how come letting air out of spare DID NOT set off the light? Seems a low spare SHOULD have triggered the light in that case, right?

Anyhow, I don't have AlfaOBD and that's not what my OP here was about. I have always run my tires at 35psi and never got a TPMS light until winter when psi dropped to 32 or less. Upon raising all 4 back to 35 the light went out. It always worked that way for YEARS. Recently disconnected my battery and that changed. Now requires 39 psi for light to go out. I have NEVER put 39 psi in these tires! I also have the "ECO" symbol coming on when cruising that I never noticed before. Maybe "UCON" updated my software or something else reset it to factory? IDK, but something changed.

 

[dieselscout80]

Interesting

I just read my 2020 Ram 2500 owners manual and it mentions TPMS in spare tire.

I need to look at my spare to see if it has a TPMS sensor/valve-stem.

 

[madtrucker2016]

I purchased my truck with dealer-installed "oversize" 35x12 tires. The dealer re-programmed the TPMS setting to 35 psi. I ALWAYS kept these tires at 35 psi and never had any trouble or warning until they went below 32 or so on cold days. I never even knew the door sticker says 39 because I always THOUGHT it was supposed to be 35!

Recently I disconnected the battery to do some work and now the TPMS warning comes on every time I start my truck saying "inflate tires to 39 psi". It seems that somehow disconnecting the battery reset the TPMS settings back to stock.

How did that happen? I thought ECU programming was "non-volatile"?

Read the tire on the vehicle, and it will tell you the correct tire pressure. I would go by that for sure

 

[04fxdwgi]

Still confused by your story. If all is working properly - and it's reading the spare - how come letting air out of spare DID NOT set off the light? Seems a low spare SHOULD have triggered the light in that case, right?

Anyhow, I don't have AlfaOBD and that's not what my OP here was about. I have always run my tires at 35psi and never got a TPMS light until winter when psi dropped to 32 or less. Upon raising all 4 back to 35 the light went out. It always worked that way for YEARS. Recently disconnected my battery and that changed. Now requires 39 psi for light to go out. I have NEVER put 39 psi in these tires! I also have the "ECO" symbol coming on when cruising that I never noticed before. Maybe "UCON" updated my software or something else reset it to factory? IDK, but something changed.

There must have been update made at some time. This is how mine was from day 1 with dash low pressure showing to re-inflate to 39 pounds, clear the warning, then back down it 35. The owners manual also explains it that way. My 16 and you 17 should be exactly the same.

There should be a softswitch on your configuration screens on the radio to turn on / off the ECO light, if I recall correctly.


Ok, one more time on the spare tire. (looking through the manual closely explains this).

The TPMS screen on dash will NOT alarm on the spare low pressure UNLESS the tire is mounted on one of the 4 tire positions and being used to replace a flat tire (or such). PS: The spare tire pressure is supposed to be 60 PSI. Side of mine states 61 PSI Max

If tire is still mounted in the spare tire carrier under the truck:
1. It will NOT alarm on low pressure.
2. It WILL alarm on a bad TPMS sensor indicated by:
A. The TPMS warning light will flash for 75 seconds and then go solid.
B. The TPMS screen will show all 4 std tires have no warnings, but still have the TPMS light lit on the dash.

 

[04fxdwgi]

Interesting

I just read my 2020 Ram 2500 owners manual and it mentions TPMS in spare tire.

I need to look at my spare to see if it has a TPMS sensor/valve-stem.

Good luck. Don't think you can tell by looking at it. I couldn't tell mine till I hit it with the TPMS tester. The tester got some reply from it, but said sensor was kaput. New sensor fixed everything