TPM Reflash

[Mark57]

I've read threads of where people talk about getting there PCM reflashed for the lower values. I have a 2026 3500 dually and my aftermarket tires and wheels ride the best with 40PSI I ask the dealer they said that it would void my warranty, not sure if that's true. Thanks Mark 

[Chuck FB]

On 12/17/2025 at 4:15 PM, Mark57 said:

I've read threads of where people talk about getting there PCM reflashed for the lower values. I have a 2026 3500 dually and my aftermarket tires and wheels ride the best with 40PSI I ask the dealer they said that it would void my warranty, not sure if that's true. Thanks Mark 

 

That is a good question, at the time of purchasing my truck I had talked to the service manager who used to be a mechanic, to see if they were willing to lower my factory placard set tpms pressures and he said while we are capable of physically doing it, no they were not allowed to as a GM dealer as they would get their hands slapped by corporate GM ( that was his way of putting it ) but did not happen to mention anything about warranty one way or the other so I have no idea about that part. He said my best bet would be to go to a tire shop or independent mechanics shop and have them do it. I ended up buying an Autel tpms tool and did it myself and not saying that is the ideal tool as its geared towards Autel sensors more than other sensor brands, it did the trick in lowering the pressures before the system triggers the dash to say I am under pressure. 

 

So I don't really have the answer to your question, GM seems pretty finicky up here in Canada with warranty because they know they can screw over the customer if they can see an out due to our lack of consumer laws like the USA has. 

[carkhz316]

Go to any competent independent shop and they can do it for you. Any modern scan tool that has bi-directional controls/ special tests functions, has been able to adjust the "low tire pressure threshold" setting in GM vehicles. This is assuming that GM hasn't suddenly locked out that ability as they have done with other things in the past.

[Mark57]

So I read that you can go on the information screen and put in off road app and i guess choose air down tires, first I have heard of this with all the threads I've read.  Mark

[kylant]

how would lowering your tire pressure void your warranty???

[Mark57]

Right? I think it's just the fact that GM is freaking out about people going into the PCM to alter any values that they see fit? Mark