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DESCRIPTION
The Tire Pressure Monitoring (TPM) system monitors air pressure in the four road tires (excludes spare). Pressure in the spare tire is not monitored. The base system does not specify how many tires are low or where they are located. The premium system does so.

NOTE: Premium Tire Pressure Monitoring is the only system used on this vehicle. Because the Premium system is based upon the Base system, both are explained here.

There are two types of TPM available, a base system and a premium system.

The Base TPM system consists of tire pressure monitoring sensors attached to each road wheel through the valve stem mounting hole, a central receiver module (WCM) and an indicator lamp.

The Premium TPM system consists of tire pressure monitoring sensors attached to each road wheel through the valve stem mounting hole, a wireless control module (WCM) three wheel sensor transponders located in three of the four wheel wells, an electronic display, and an indicator lamp.

The receiver circuit for the TPM system is integrated into the WCM. Commonly referred to as the Sentry Key Remote Entry Module (SKREEM), the WCM also includes the Remote Keyless Entry (RKE) receiver and the Sentry Key Immobilizer (SKIM) receiver. All three receivers share a number of common components. The WCM decodes the RF signals transmitted by each of the vehicle’s tire pressure sensors. The decoded information is used to determine if "warning" or "fault" conditions exist within the TPM system.

Upon detection of a warning or fault condition, the WCM will send a request to the module that controls the indicator lamp (and the text display if equipped with the Premium system) via the vehicle bus system to illuminate or flash the indicator lamp. Also, upon detection of a warning or fault condition, the electronic display will send a request to sound the "chime". A chime will only be requested once per ignition cycle per warning or fault condition detected.

The WCM will store all warning and fault conditions, placard pressure values and low-pressure threshold values (lamp ON and OFF) in memory that can be accessed through diagnostic communication. If new sensors are introduced to the vehicle, the data stored for the sensor being replaced will be deleted.

The WCM will store all wheel sensor ID’s and locations and faults in memory that can be accessed through diagnostic communication. All other data values transmitted from each active wheel sensor (not the spare tire) shall be stored in the WCM memory.

The WCM automatically learns and stores the sensors’s ID while driving “within 10 minutes continuously above 15 mph (24 km/h)” after a sensor has been replaced. The learning sequence will initiate when the vehicle has been stopped for more then 20 minutes.

OPERATION
NOTE: Premium Tire Pressure Monitoring is the only system used on this vehicle. Because the Premium system is based upon the Base system, both are explained here.

BASE TIRE PRESSURE MONITORING
The tire pressure monitoring system (TPMS) is designed to operate without loss of function for all OEM tire construction for this vehicle. Sensors, mounted to each road wheel as part of the valve stem, transmit an RF signal indicating their individual pressure to a receiver located in the Wireless Control Module (WCM), commonly referred to as the Sentry Key Remote Entry Module (SKREEM). On a Domestic vehicle, the TPM sensor operates on a 315 MHz radio frequency. Export vehicle sensors operate on a 433 MHz radio frequency. These transmissions occur approximately once every minute at speeds over 15 mph (24 km/h). For more information on sensors, (Refer to 22 - TIRES/WHEELS/TIRE PRESSURE MONITORING/SENSOR - OPERATION).

If the TPM system detects that the tire pressure in any road tire is going low, beyond the Low Pressure (lamp) ON threshold (see placard table below), the TPM system will continuously illuminate an indicator lamp. If a system fault is detected, the indicator lamp will flash on/off for 60 seconds, once every 10 minutes.

If the WCM detects a warning or fault condition at ignition key "on" it will wait ten seconds +/- 10 % before sending the first request to illuminate the indicator lamp. This will assure that the display module has concluded its bulb check period. The display module will request a chime once per ignition cycle for each "warning" or "fault" condition detected. A "warning" or "fault" condition will remain enabled until the problem causing the condition is corrected and removed/reset.

The WCM shall continuously monitor for the receipt of tire pressure RF message transmissions from the wheel sensors during both the ignition key "on" and key "off" cycles. The wheel sensor ID’s and the location of each sensor (e.g. Tire 1, Tire 2 etc.) are stored in the WCM non-volatile memory during the initial Manufacturing Plant Process, or during a service procedure, as required.

The TPM System will continue to warn the driver of low tire pressure as long as the condition exists, and will not turn off the indicator lamp until the tire pressure is at or above the Low Pressure (lamp) OFF threshold (see placard table below). The system will automatically update and the TPM indicator lamp will extinguish once the updated tire pressures have been received.

Tire pressure will vary with temperature by about 1 psi (6.9 kPa) for every 12°F (6.5°C). This means that when the outside temperature decreases, the tire pressure will decrease. Tire pressure should always be set based on cold inflation tire pressure (placard pressure). This is defined as the tire pressure after a vehicle has not been driven for more than 3 hours (and in outside ambient temperature). The tire pressure will also increase as the vehicle is driven; this is normal and there should be no adjustment for this increased pressure. For a system fault, the system will return to normal once the WCM receives a valid transmission from that sensor location.

PREMIUM TIRE PRESSURE MONITORING
The operation and lamp/chime strategy of the Base Tire Pressure Monitoring System (TPMS) also applies to the Premium TPMS, but the premium TPMS can display text messages and a tire pressure graphic display on the information cluster. If a low pressure condition is detected, in addition to a chime and indicator lamp turning ON, the Electronic Vehicle Information Center (EVIC) will show a graphic display of the pressure value(s) with the low tire(s) flashing. Once pressure in the suspect tire raises above the Low Pressure (lamp) OFF Threshold (see placard table below), the lamp will go out once the WCM receives a valid transmission from the sensor. If a system fault is detected, in addition to a chime and a indicator lamp flashing, a “Check TPM System” text message will be displayed in the instrument cluster, and the tire pressure graphic display will have “- -“ in place of the pressure value. The system will return to normal once the WCM receives a valid transmission from that sensor location.

The Premium TPMS determines the location of the tire pressure sensors by using transponders located in three of the four wheel wells on the vehicle. A fourth transponder is not necessary in the remaining wheel well due to the process of elimination theory. Once the system knows the location of the first three sensors, it assumes the location of the fourth tire pressure sensor, and updates the graphic display when necessary. For more information, (Refer to 22 - TIRES/WHEELS/TIRE PRESSURE MONITORING/TRANSPONDER - OPERATION).

For both the premium and base TPM, the recommended "Placard Pressure", "Low-pressure Threshold" and “Hysteresis Pressure Values” for the tires installed on the vehicle, are stored in the WCM non-volatile memory during the initial Manufacturing Plant Process, or during a service procedure, as required. To determine the pressure thresholds for a vehicle, refer to the Tire Inflation Pressure (Placard) Label, and then apply the placard pressure to the following table. The Low Pressure OFF Threshold is defined as the Low Pressure ON Threshold plus the Hysteresis Pressure Value.

For further information, refer to the Owners Manual or the Appropriate Diagnostic Information.



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I have just changed the original wheels and tires for winter & snow with steel wheels and snow tires; I live in Canada. Of course, the new snows come with new valves. The TPMS warning light is now on continuously and it will be until I put back the all season wheels and tires in April.

My question is: is there a way to either remove the appropriate fuse, and if so - which fuse; OR is there a way to temporarily remove the feature from the vehicle's computer?
 

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I have the same problem in reverse here Branko, summers don't have the TPMS. I have found it very easy to ignore the chimes at startup and the light on the dash, if the light were too bothersome I'm sure a small piece of black tape would solve that, in the meantime I think of the money I saved not paying for another set of TPMS sensors with the wheels and tires
 

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I could have bought a lot of electrical tape with the $100 I spent on 4 TPMS sensors shipped from Amazon.

I wonder what it will cost to replace an instrument cluster lens that was scratched while removing the electrical tape.
 

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So there is no way to "disable" the chime and or light every time I loose 1psi of air!?
 

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If a system fault is detected, the indicator lamp will flash on/off for 60 seconds, once every 10 minutes.

How do you correct this problem? That's what mine is doing!
 

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Check TPM system?

I just got the tires rotated on Thursday on my 2010 Patriot Limited. On Saturday, I first noticed that when I turn the car on, it says "Check TPM System", and then goes to the tire pressures, which has readings for all 4 tires. It doesn't alarm, I get no other warning lights. Is this something that could have happened during the rotation?
 

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These type of low tire pressure warning systems are one of the worst "innovations" that the car industry has ever come up with. They need to come up with a way to make it better or just get rid of it. I think people are capable of checking their own tire pressure.
 

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Hello, i got patriot 08 limited , i have this system to? If i do, how can i see that in the car options?
There is a light for this system (yellow lamp) if something is wrong, and you can read the tire pressure in each tire by pressing the button for the car computer. (the one under the speedometer)
 

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Yes, I know what you mean--however, if you're under 30, you may not understand that concept--recently in OR, they rescinded a law not allowing self-serve gas stations, and when some young folks had to pump their own, many had difficulty--shame.

The EVIC system--an option--allowed a 4 wheel at a time display, so you could verify all the tires, and that was nice.
 
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These type of low tire pressure warning systems are one of the worst "innovations" that the car industry has ever come up with. They need to come up with a way to make it better or just get rid of it. I think people are capable of checking their own tire pressure.
Agreed!

Pres. Obama had an idea that everyone was driving around with soft tires, wasting fuel, and contributing to global warming. He was wrong, but when has that ever stopped Washington?

I wonder how much fuel I've wasted stopping & starting to check my tires when I got a false indication? Actually I've learned to ignore it. It always comes on when there is a drop in temperature, say from summer to fall -- 75 one day / 30 the next morning. Bing! It says soft tire. I'll drive a few miles, stop for coffee, and it goes away. Might do it for a couple more mornings until it gets used to the new cooler weather.

Then it happens again when the weather changes from fall to winter -- 35 one day below 0 the next morning. Bing! Its deja vu all over again. Once it gets used to winter it goes away.

Haven't noticed it on the transitions from winter to spring to summer however.
 

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I was driving in town recently and smelled burning rubber. Noticed that the lady driving along unconcerned in front of me had already destroyed one of her rear tires and was driving on a loose tread (sidewalls were shredded). No, I don't believe that people can be relied upon to check their own tires or even to recognize that anything is wrong.
Cute to see that blaming Obama for everything is still going on, but this started long before. I recall TPMS showing up on some Fords in the late '90s, and Wiki says they were on Corvettes with run flats in 1991. The legislation requiring TPMS on all vehicles was passed in 2000 as a response to the Ford/Firestone rollovers in the '90s. And roadside inspections routinely find people driving on underinflated tires.
If it was up to me I'd make it even more draconian - for example limit vehicle speed if a tire is reading low.
 

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Thank God you are not in charge dude. Just saying.............
 

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I was driving in town recently and smelled burning rubber. Noticed that the lady driving along unconcerned in front of me had already destroyed one of her rear tires and was driving on a loose tread (sidewalls were shredded). No, I don't believe that people can be relied upon to check their own tires or even to recognize that anything is wrong.
:doh: She is probably married to the guy that shot a dairy cow and thought he had a buck!
Cute to see that blaming Obama for everything is still going on, but this started long before. I recall TPMS showing up on some Fords in the late '90s, and Wiki says they were on Corvettes with run flats in 1991. The legislation requiring TPMS on all vehicles was passed in 2000 as a response to the Ford/Firestone rollovers in the '90s. And roadside inspections routinely find people driving on underinflated tires.
I just remember Obama making a speech about it.
If it was up to me I'd make it even more draconian - for example limit vehicle speed if a tire is reading low.
Draconian? Agreed. But on the bright side, because there are so many false readings, it would probably eliminate the necessity of speed limits on the highways. I can only recall one time (of several dozen) that the TPMS was correct and it was obvious. It was an instant flat and I was just trying to get to a lighted place to install my spare.

Now here's an idea: How about a governor that won't let a car exceed the speed limit? If it does, it summons the police because there must be an emergency. If there's no emergency it becomes a false report to police = arrest, night in the cooler, judge, lawyer, $$$, etc.
 
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