I didn't say I was running at 30psi I said THAT was the recommended pressure, (door sticker). I had been running at 34psi all along. Besides, the sensor doesn't know what size tire is wrapped around it, it only recognizes pressure. So even if 30psi wasn't ideal for that size tire it still shouldn't have tripped a sensor designed to see 30psi as optimal. If "the TPMS on our trucks want to see at least 35-38psi" then EVERY H3 ever made, and running at door sticker O.E.M. pressure, would be activating the LOW TIRE PRESSURE light.

 

X2, it IS true

 

And........ that is exactly what has happened for years until owners wised up and inflated to 35-38psi. Every H3 I had is always at 38PSI. When I do a road trip, 40PSI.

I must have posted here back in the days of waves of threads started by peeps saying my TPMS warning, my TPMS this or that...... like 50+ times, inflate to 38PSI and your problem will go away.

 

I agree, Doc, that raising the PSI over the door sticker is ideal, but as I said, EVERY H3 ever made, (almost 160,000), would have experienced the LOW TIRE PRESSURE warning if the TPMS needed 35-38 psi to not trigger.

 

I have my doubts about that. After all, if that were the case, then why wouldn't everyone who complains about their TPMS simply do that? Besides, bypassing the system (in any way) doesn't make what I've said about it untrue; per the Owner Manual: SERV TPM appears if the system isn't working correctly, LOW TIRE appears if one or more of the tires are low.

 

Now I'm curious as to what my sticker says. I've never known a vehicle to recommend tire pressure that low (30psi); I'll have to look when I get home.

 

SERV TPM is triggered when a TPMS sensor is not transmitting a signal to the BCM. LOW TIRE is triggered when a low signal is transmitted. No antenna=No signal to the BCM=No SERV TPM/LOW TIRE.

 

You're missing {{{{{{COLD}}}}}}...SET PRESSURES COLD. Check outside at the current temp 23°F, 30psi should be enough, or simply raise the pressures a few psi for winter. '08 sticker shows same on all H3's:

 

^^^^^^^^ I get it. The pressures WERE set and CHECKED when the tires were 'cold' which really means not having been driven recently. You're confusing 'cold' with 'ambient'. If tires could only be set and checked when 'cold' people living in Florida would have a hard time accurately setting and checking their tires.

1. START WITH COLD TIRES IF POSSIBLE. Vehicle manufacturers specify PSI – literally “pounds per square inch” of pressure – assuming tires are cold. Tires are considered cold when the vehicle has been parked for three hours or more, or if the vehicle has been driven less than a mile (1.6 km) at moderate speed.

 

Which is exactly what I said, isn't it? Low tire = LOW TIRE message. ECM not receiving a signal (that could mean dead sensor battery OR disconnected antenna) = SERV TPM message. Which is what the owner manual states. You claimed that disconnecting the antenna would NOT result in the SERV TPM message (post #19). Now you claim that it will (post #27). I swear, Hummerz, sometimes I think you post just to stir the pot.

BTW, not all H3's show 30psi. H3s with 285 tires call for 35psi. Here's my door tag:



If my pressure drops below 34-35psi, the TPMS alerts me to a low tire; EVERY time, and would often alert first thing in the morning when cold out (till the tires warmed up) Running them at 38 stopped the issue completely (thanks, Doc), and now my 305/70-16 BFGs are happier at 40psi.