Tire Pressure Monitoring System


I have a 2008 GMC 3/4 ton Sierra that has a tire pressure monitoring system. i would like to run 45-50 psi in the rear when I’m empty and more psi according to the load carried. To the best of my knowledge, the only way I can change the settings is to have a dealer do it, which would be incovenient and possibly costly. Is there a more user friendly method?


I believe you can up the psi and all it will do is to give the alert.

I would suggest two things:

  1. Check the MAX inflation listed on the tyres. NEVER exceed that number. If it is too low then you have the wrong tyres and they are unsafe on your vehicle.

  2. Read the owner’s manual. Straying from from the recommended inflation can cause unexpected and unsafe handling changes.


i would like to run 45-50 psi in the rear when I’m empty and more psi according to the load carried.


What is the recommended tire pressure on the driver’s door frame and the owner’s manual? If 45-50 PSI is within the recommended tire pressure, you should not have a problem. If it isn’t within the recommended tire pressure, don’t do it.


Stay within the ranges specified in the owner’s manual.

While you’re in there, look up the protocol for reinitializing the low tire pressure warning system. You might have to do so when you adjust the pressures. I have to do mine every time I even do a tire rotation. The manual says so, and I’ve found it to be true.


can you reinitialize tire pressure system when the sensors are in the valve stem? I can’t on a 2007 RAV.


I don’t know. I’d be surprized if you could not. The system needs some method to reference itself to the pressure that the driver uses based on his/her driving environment, tire size, ride preference, etc.


The TPMS sensors on my Pacifica operate in a narrow, non-adjustable range. YMMV


The manual states using the pressure noted on the door frame. That pressure is 80 psi for the rear and 50 psi for the front. I am not going to, nor is it recommednded by the tire manufacturer to run at 80 ps with an unloaded truck. The manufacturer (Bridgestone) recommends 50 psi undloaded and up 80 psi when the truck is loaded to is max.

I tried to reinitialize the system after lowering the pressure, but still got the alarm.


The recommended pressure that is listed on the door frame for the rear tires is 80 psi. If I was to operate the truck unloaded with the rear tires at 80 psi. the tires would be crowned affoding reduced traction, expecially if it was wet. The 45-50 psi was recommended to me by the tire manufacturer. It just makes sense that you should have the same amount of rubber on the road regardless of the truck being unloaded or loaded. The only way to accomplish this is to vary the tire pressure.


You are taking advice from the wrong person. The tire manufacturer is not the correct source for air pressure in these tires. The vehicle manufacturer is who you should be listening to.

This vehicle has been tested to determine the proper tire inflation for the best handling and tire wear. If you do not run the tires at the proper inflation recommended by the manufacturer you could be voiding the warranty of the tires.

If you run the tires at 45 psi (when the recommended pressure is 80 psi) the tire will be under-inflated which could lead to a major tire failure and accident.


LT tires should be inflated according to the load. The best way to do this is to weigh the end of each axle. You should be able to come up with some pretty fair interpolated estimates after you have weighed the axles unloaded and with a couple of known loads in there. The tire manufacturer should be able to provide you with a table containing the recommended inflation pressure for the whole load range. Pressure will be noticibly lower for lower loads. 40-50 PSI sounds pretty reasonable to me for a ? ton empty with LT tires. If these are the standard tires, you could be pretty near the max inflation pressure when fully loaded.

To answer your question, you may be able to get at the inflation pressure monitor issue with a tuner that you can use to change settings in your PCM. I would go to a GM LT board and see if anyone knows if the data for the monitoring system lives there and if you can access it. I would think that experienced haulers would be pretty upset that they can not adjust the pressure in their LT tires without upsetting this system. Even if you can do it with a tuner, if you change inflation pressure often it might be too much of a pain. If that is the case, you might be able to disable the system with the tuner as well.

I think you are getting the right advice from the tire manufacturer. It is a pity that the truck manufacturers have been forced to dumb down their manuals so much.


You have high pressure tires and you can should probably run them right up to 50 PSI. If they say 45 is OK then I won’t contradict them. If the pressures listed on the tire say the minimum pressure, never go under that. Those tires won’t ever get good traction, so just don’t run them at the lowest pressure.