Help! Tire Pressure Monitoring Sensor System needs service...

[AV8R]

This week my C6 Vette 2008 basic coupe’s main battery went dead. Curiosly, so did the keyless remote fob’s battery, because I couldn’t unlock the door after recharging the car battery - the two situations being related, I just don’t know. Anyways, I chargd the car and replaced the fob batteries. Both worked fine, so I took her out for a ride (was sitting for about 3 weeks) to make sure the battery was fully charged and not a near dead battery (it’s original afaik). It holds strong at 13.6v when driving around, and starts right up.

So good this far, until I see that ubiquitous yellow tire pressure system icon has not gone away and low and behold, there’s a DIC message indicating that the tire pressure system needs servicing. When I check the DIC tire pressure page it shows “XX” in all four tire positions. Not good.

Off to Corvette forums and YouTube for TPMS information on how this happens and how to reset or reprogram either the TPMS or Fob or both. Lots of stuff out there from:
- replacing all four wheel TPS (not cheap, about $60 each plus labor)
- resynch the Fob (since its battery died and was replaced)
- relearn the TPMS for each wheel’s TPS (different ways: magnet, special device, releasing pressure)

Id rather not have to replace the 4 TPS if this isn’t really necessary, rather it being a computer initialization or synchronization issue due to the loss of power on the fob and car batteries.

Unfortunately, Ive yet to find a definitive way to know which corrective path to take. Also I’ve not found how to relearn the tire pressure for the TPS for a 2008-C6. Seems that the older C5 used a slightly different TPS and procedure for relearning than C6, and I’ve not been able to get my vette into a relearn mode by pressing both the lock and unlock buttons simultaneously on the fob, whilst the car is running or in accessories mode.

What I need is help with discerning if I need to replace all four TPS devices or if there is a step by step procedure I can follow to restore the TPMS without having to go all in (which assumes the 4 TPS batteries are fine)

And if I must buy four TPS (ACDelco 25758220 GM Original Equipment Tire Pressure Monitoring System (TPMS) Sensor), and knowing:
a. that they have a battery life of up to 10 years
b. that they have been around for C6 vette s since 2005

How does one know when they buy “new” ones that the internal batteries aren’t already mostly used up, being it’s now 2018?
(do they have a expiration or make date code?)


Sites that I already looked at:

C6 reset with tool
https://m.youtube.com/watch?v=64-4mnwWwN0


Reset by releasing air
https://m.youtube.com/watch?v=LCmKoTsD9iY


Reset with magnet
https://m.youtube.com/watch?v=uplJ8AaNKjw

Fob resetting:
http://www.corvetteforum.com/forums/c5-tech/3640798-tpms-key-fob-module.html

 

[LLC5]

This week my C6 Vette 2008 basic coupe’s main battery went dead. Curiosly, so did the keyless remote fob’s battery, because I couldn’t unlock the door after recharging the car battery - the two situations being related, I just don’t know. Anyways, I chargd the car and replaced the fob batteries. Both worked fine, so I took her out for a ride (was sitting for about 3 weeks) to make sure the battery was fully charged and not a near dead battery (it’s original afaik). It holds strong at 13.6v when driving around, and starts right up.

So good this far, until I see that ubiquitous yellow tire pressure system icon has not gone away and low and behold, there’s a DIC message indicating that the tire pressure system needs servicing. When I check the DIC tire pressure page it shows “XX” in all four tire positions. Not good.

Off to Corvette forums and YouTube for TPMS information on how this happens and how to reset or reprogram either the TPMS or Fob or both. Lots of stuff out there from:
- replacing all four wheel TPS (not cheap, about $60 each plus labor)
- resynch the Fob (since its battery died and was replaced)
- relearn the TPMS for each wheel’s TPS (different ways: magnet, special device, releasing pressure)

Id rather not have to replace the 4 TPS if this isn’t really necessary, rather it being a computer initialization or synchronization issue due to the loss of power on the fob and car batteries.

Unfortunately, Ive yet to find a definitive way to know which corrective path to take. Also I’ve not found how to relearn the tire pressure for the TPS for a 2008-C6. Seems that the older C5 used a slightly different TPS and procedure for relearning than C6, and I’ve not been able to get my vette into a relearn mode by pressing both the lock and unlock buttons simultaneously on the fob, whilst the car is running or in accessories mode.

What I need is help with discerning if I need to replace all four TPS devices or if there is a step by step procedure I can follow to restore the TPMS without having to go all in (which assumes the 4 TPS batteries are fine)

And if I must buy four TPS (ACDelco 25758220 GM Original Equipment Tire Pressure Monitoring System (TPMS) Sensor), and knowing:
a. that they have a battery life of up to 10 years
b. that they have been around for C6 vette s since 2005

How does one know when they buy “new” ones that the internal batteries aren’t already mostly used up, being it’s now 2018?
(do they have a expiration or make date code?)


Sites that I already looked at:

C6 reset with tool
https://m.youtube.com/watch?v=64-4mnwWwN0


Reset by releasing air
https://m.youtube.com/watch?v=LCmKoTsD9iY


Reset with magnet
https://m.youtube.com/watch?v=uplJ8AaNKjw

Fob resetting:
http://www.corvetteforum.com/forums/c5-tech/3640798-tpms-key-fob-module.html

There are dedicated TPMS tools that can tell you the status of your TPMS sensors, a Schwab or Discount tire may check them for free. Good question on the sensors batteries, I have wondered that also, I have never seen a born on date on one yet. The sensors are supposed to go into sleep mode until rotated so the batteries will not have been used but any battery will go bad just sitting.

Have your vehicle battery load tested with a carbon pile tester, just because it can start your engine does not mean that it is good or healthy. Any battery that has gone flat is suspect to internal damage (even new battery's off the shelf for that matter).

 

[AV8R]

@LLCS,

Good idea about going to a tire store for a TPS health check (free hopefully)

When a car and/or Fob battery go dead, at the same time or separately, does the TPMS system have to relearn the TPS data for each wheel (assume the TPS batteries are good)?

And if yes, what is this procedure for the 2008 C6?

 

[LLC5]

@LLCS,

Good idea about going to a tire store for a TPS health check (free hopefully)

When a car and/or Fob battery go dead, at the same time or separately, does the TPMS system have to relearn the TPS data for each wheel (assume the TPS batteries are good)?

And if yes, what is this procedure for the 2008 C6?

Yes, it does have to relearn the sensors. Have you driven the vehicle for about 20 mins. after the battery went dead? If not, drive it for a while and see if system comes back up.

 

[AV8R]

I did drive my 2008 C6 after I got the batteries sorted for about 30 minutes. The blank pressure values went to XX for each tire. This tells me that when both the car and fob lose power, the data is lost or reset. Can someone verify this?

So American Tire wants to charge me $40 to relearn the tpms system. I can get the a device on Amazon for $20: [h=1]VXDAS EL-50448 Auto Tire Pressure Monitor Sensor TPMS Relearn Reset Activation Tool OEC-T5 for GM Series Vehicle[/h]https://www.amazon.com/gp/product/B072BK693N/ref=oh_aui_detailpage_o00_s00

theres a concern if these work for GM vehicles older than 2010, but this document indicates it should work due to firmware upgrades:

https://srs20assets.service-solutio...Downloads/Document Library/EL-50448_rev_1.pdf

 

[AV8R]

Conclusion

So the happy ending of this story is that:
a. I was correct in that a dead main battery will cause all four TPMS devices to go out of synch with the car’s computer when a new battery and power is restored. The coincidence of all the tire pressure value being XX right after replacing the battery indicated to me that it wasnt dead sensors. Statistically low probability that all of them dying at the same time.

b. The $20 sensor I bought off the link above did not work for my 2008. Its actually for 2010 and newer.

c. American Tire used their TMPS relearning device and it worked fine, and for free. When i called the manager a week ago, he said it cost $40. Makes me wonder what was going on there.

d. With the car running or in power accessories mode, Pressing both the lock and unlock buttons on the OEM FOB puts the car into TPMS relearn mode, and beeps the horn once. Then the handheld teaching device is put near the left front wheel at the valve stem. When done, it beeps again and the next wheel is going around the car in a clockwise manner. Oddly enough, the turn signal for each corner did not turn on as Ive seen on YouTube for other GMC vehicles, nor did the DIC display it was in the relearn mode.

e. Then the digital info console above the steering wheel will show the correct pressure instead of XX or blanks.

If only one or two tire positions read XX or Blank, instead of all four, and the relearn process fails; then i would suspect the TPMS sensor device battery has died in that wheel. Especially if its over 8 years old. When getting replacements, make sure its expected 8-10 year battery life is already used sitting on the shelf. They do have manufacturing date codes if from GMC Delco.