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TPMS Fail

1K views 8 replies 3 participants last post by  RUFFSTUFF 
#1 ·
I'm not reporting a failure with the sensors, more of just a failure in the design of the system. Before going into it, the background of how I came to this discovery, 3 months ago, after getting new tires, my Low Pressure light came on, all tires were at the correct pressure. After towing a 9K lbs boat to florida for a friend, the whole way the truck felt like the steering was loose in the front end, and the back felt like it was floating side to side. Got down there, had a dealer check the truck out , steering linkage was solid, swaybars solid, nothing wrong mechanically. Now the problem seems to only happen above 55, at 75-85 almost feel like the truck is going to go off the road. So I get back up north, take the truck to get tires rotated and road force balanced, they fixed the floating in the rear end, and added some pressure to the front tires. Going down the road, since that time the truck seems to be more under control, not 100% but a lot better. So yesterday I took my truck to the dealer to get the tire pressure sensors checked and replaced if necessary. after 30 mins, they said they just needed to adjust the pressure, Service Manager said: "Manufacturer Specs for the TPMS system are: 65 PSI in front, 80PSI in back", so I figure great, I'm out there in less than an hour and only out $40. On my way home up to 65, I noticed the truck seemed to be wandering a bit, It was fine in the morning, wind was blowing a bit, so I ramped it up to 75, and what would you know the truck wanted to wander all over the place. My tires were at 80PSI front 70 PSI rear that morning. So I call the srvc manager, I tell him, the truck is all over the road, he says I can up the pressure, but the light will come back on. So my choices are drive with the annoying light or drive with an out of control truck.
In my book that constitutes a total FAIL for a system that is supposed to improve safety in the truck. For a car or an SUV those pressures are fine, but not for a truck pushing 9300lbs, its completely unsafe.

Now a question for the techs, is there any way to tweak the TPMS system, like changing the parameters, I honestly dont understand why it would think there is low pressure when the tires are filled above what they are supposed to be, according to the specs.

James.
 
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#3 ·
So you're calling FAIL on something that hasn't happened yet? Your truck wandering all over the road has nothing to do with the sensors... Fill the tires to the recommended cold pressures and if you have problems with that chase after your wheels/tires/suspension. The TPMS light after your new tires was simply the tech forgot to retrain the TPMS system.

AT NO TIME, should you have to overpressurize your tires to drive straight.
 
#4 ·
Both front Hubs and bearings were just replaced a month ago. I've been to 3 dealers in 3 different states and 2 mechanic shops in different states, All 5 said the steering components are solid, the suspension is solid. The Wheels and tires as I said were road force balanced which is pretty much the best balancing you can get.
After all that, you still say its something else, tell me why my truck felt solid yesterday morning at 80mph, 80PSI front, 70 PSI rear; then they switch the pressures around and the truck feels very loose at 80.
I'm not imagining this.
 
#5 ·
All I know is I recently replaced my Terra Grapplers and I ran those at 70psi normally, 75psi when pulling my trailer. Never had a single issue.

TPMS is designed to warn of a low pressure condition, this is the first time I have ever heard of a TPMS warning from a higher pressure. Since you have yet to say that you upped the pressure and the light came on, did it?

How long was it from the time you replaced the tires until you noticed the issues you are having?

What did the shop do to fix your "floating in the rear end"?
 
#6 ·
Ok, so I upped the pressure in the front from 65 to 70, the truck feels more solid, and the light did not come on.

The current set of tires I have were replaced right after Christmas, and that's when I drove down to FL, and right away was noticing the problems. My friend who mounted and balanced the tires had a new guy do the balancing, so I think that caused a lot of the balancing problem. When I was down in FL, I had a dealer try to balance the tires again, they said two of them needed 10 ounces of weight.
When they road force balanced the tires, they said whoever did it before them, really had know idea what they were doing.

The floating hasn't really stopped altogether, but after the tires were balanced properly, it isn't nearly as bad as before.
 
#7 ·
So, care to revisit that TPMS fail idea?
 
#8 ·
I still think one should be able to tweak the pressure parameters for the sensors.
 
#9 ·
No manufacturer is going to accept the liability to provide that feature.
 
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