TPMS question

It seems my tps light comes on about every 3-4 month. I check all the tires and they are usually about 28-30 psi. Door states they sound be at 29 psi. I then fill all of them back to 30 psi and the light will go away.

Does anyone know at what psi they are triggered?

Would 28 really set one of them off?

Also, I usually keep my spare much higher (about 35-40 psi), so I don't have to crawl under it all the time. Would that be doing it?

 

you can set the TPMS pressures. There is a button on the lower dash directly below the steering wheel. I dont know the exact procedure but its all detailed in the owners manual.

 

I think they have to be within the same range...if it goes to high or low it will give a light

 

They may be nearing the end of there life. From what I read, they last between 5 to 7 yrs. I believe they have a small battery inside the basically goes dead. Since yours is an 09, your right at the end of there life. 7 yrs.


http://blog.performanceplustire.com/how-long-do-tpms-sensors-last/

 

thanks, I had no idea. If i'm reading this correctly if I reset it, it will use the current pressure as the new level. However, i'm still unsure when does it trigger it to go off again?

Initializing the tire pressure warning system ■ The tire pressure warning system must be initialized in the following circumstances: ● When rotating the tires on vehicles differing with front and rear tire inflation pressures. ● When changing the tire inflation pressure by changing traveling speed or load weight, etc. ● When changing the tire size. When the tire pressure warning system is initialized, the current tire inflation pressure is set as the pressure benchmark. ■ How to initialize the tire pressure warning system Park the vehicle in safe place and turn the engine switch off. While the vehicle is moving, initialization is not performed. Adjust the tire inflation pressure to the specified cold tire inflation pressure level. (P. 475) Make sure to adjust the tire pressure to the specified cold tire inflation pressure level. The tire pressure warning system will operate based on this pressure level. Turn the engine switch to the ON position. Push and hold the tire pressure warning reset switch about 3 seconds, and after releasing the switch the tire pressure warning light blinks slowly three times. Wait for a few minutes with the engine switch on, and then turn the engine switch to the ACC or LOCK position

 

Correct you are setting it to base its lower limit on the new pressures associated. I want to say if the pressure gets 25% lower than set it turns the light on. So say a tire was set at 30psi 25% of 30 = 7.5 30-7.5 = 22.5psi is the tipping point where it will set off a light.

 

Great. I'm guessing that means it must be currently set to high according to the R265/65/17 sticker on the door.

 

Probably.

I know i reset mine when i got new tires to the pressure i like to run at (34 front 31 rear) as i wanted the TPMS alert me properly.

 

i run my psi at 40lb both front and rear unless on a trail then i air down. set the tire psi where you want it to be "normal" with the key on press and hold the set button and wait till the tpms light flashes. the pressure to kick the light on is usally 7-10lb low or high depending on what the pressure is when you hit the set button

 

Based on experience, it's got to be more sensitive than that. I look at my tires funny and the TPMS light comes on. Weather drops below 50 degrees and my TPMS light comes on.

I painstakingly check them all and it seems like I have to get them all within a 1 or 2 PSI to shut it off. Maybe mine are dying?

 

I know in my techstream software it shows the current psi and the low limit psi, I could grab that and do math. maybe it was down around 15%

 

most tire shops have a tool to check the sensors without touching the tire. my itm tool tells me everything about the sensor from batt life to temp of the tire. some shop will check for free or a small fee. also i have seen intermittent battery issues when there on there way out. if this is the issue watch the tpms light when the truck if first cranked. if it goes right off then lights up and stays lit its a pressure issue if it blinks steady then stays lit you may have a dead sensor.

 

thanks gang, did the reset thing over lunch. hopefully that ought to solve my problems.

I've owned the truck for 18 months and I'm embarrassed I never noticed that thing under the steering wheel.