MikeSVT04

every once in a while my tpms system stops working(service tpms). Each time this has happened I have been driving around town for an extended period of time and the car is very hot. Today this happened again and I realized that the FOB is in the center consol and each time this happened it has gotten very very hot. Then later when the car/fob has cooled off the service light goes off.

Is the fob connected to the tpms. Could the Fob be getting to hot and messing with the signal? or am I way off.

edit..these incidents have been months apart. not every couple days.



thanks

Mike

foremaw

Although heat may be a factor in a related component, I know of no connection whatsoever between between the FOB and the TPMS.

MikeSVT04

i see. I thought the key fob and tpms sent their signals to the same place.

edit: started the car today and the sensors are working fine....definitly heat realated.

Bill Dearborn

They both send signals to the remote control door lock receiver. My FOB gets so hot I can't hold it in my hand and I don't get any Service TPMS messages. However, the RCLDR could still be causing a problem intermittently.

Bill

BEZ06

Hi Mike

NOT heat related!!!

What makes you think the tire pressure sensors are working okay???

Just because the DIC is reporting pressures does not mean that the sensors in the wheels on the car are properly programmed into the TPMS computer in the car.

You are correct that the TPMS computer is actually part of the RCDLR (Remote Control Door Lock Receiver) module of the keyless entry system.

Have you changed to a new set of wheels that have a different set of sensors in them, or are you still running your OE sensors?

If you have new sensors, they may not have been programmed into the TPMS.

To make sure they are working properly, you need to check the tire pressures with a handheld gauge and make sure they are close to what the DIC reports. You could change air pressure in the tires and see if the DIC reports the change, but you'll need to drive the car faster than 20 mph for a couple minutes to get the sensors to transmit the new pressures to the TPMS.

You can also make sure they are properly programmed in by checking that the DIC pressures increase as you drive the car and the tires heat up. If the pressures don't change then the sensors aren't programmed, and the DIC is reporting the last known pressures of your old sensors.

You say you get the "Service Tire Monitor" DIC message after driving for a while, and you attribute that to heat.

However, when you drive with no sensors, or sensors that aren't programmed into the TPMS (same as no sensors at all), after a period of time (about 60 minutes on a 2005-2006, about 30 minutes on a 2007-2008, and about 20 minutes on a 2009 or newer) without the TPMS receiving any transmissions from the sensors, the TPMS decides that something must wrong with itself and gives you the "Service Tire Monitor" message.

So....what you think is heat related, I think is time related because your sensors aren't programmed into the TPMS computer.

Butt....if your sensors are programmed in, then I don't know what the problem is!!

But it's NOT heat related!

Good luck!!

Bob

MikeSVT04

OE sensors...had them checked at a local performance shop and are woking fine.


I drive to work all the time and its a longer ride than when this happened. IDK

BEZ06

How did the performance shop check the sensors???

If all they did was a diagnostic check of the sensors to see if they are working okay and have good battery strength, that doesn't mean anything.

I can take my TPMS tool and walk up to any Vette (or any other car with sensors) in a parking lot and check the sensors to see if they're working properly, but that doesn't tell me anything about whether they're properly programmed into the TPMS in the car.

The only way to easily tell if they are programmed in is to either actually program them into the TPMS again (a confirmation honk of the horn at each wheel tells you for sure that the sensor's ID# is logged into the TPMS memory), or change pressure in the tire and see if the DIC shows the change in pressure (but you have to drive the car faster than 20 mph for a few minutes after changing pressure).

You can see in the video below that I use 3 different tools to check if a sensor is good or not, but I still know nothing about whether it's programmed in to a car or not:



So.....your sensors may well be programmed into your car, but unless you do something to check them to find out you'll never know for sure.

The easiest way to check is to see if the pressures in the DIC increase as the tires heat up while driving. If the pressures stay the same day after day then it's likely that something happened to the TPMS memory of your sensor ID#'s and they need to be programmed in again.

If they're programmed in properly then I don't know why you would get the "Service Tire Monitor" message unless perhaps you actually have a TPMS problem. But, considering that the TPMS is part of the RCDLR, if you aren't having any other problems with the fob or other keyless entry features, I wouldn't suspect the TPMS actually has a problem.

Check out to see if you have changes in DIC reported pressures as you drive and the tires heat up.

Good luck.

Bob

MikeSVT04

ok The tire pressure changes as the tires warm up.


BEZ06 thanks for the great write ups. Very informative.

Zoxxo

An interesting story re: TPMS...

Recently I needed my left front wheel replaced. (I was not present for any of this, btw.) The tire shop said that the sensor needed to be replaced. Ok.

I get the car back and all is fine. Check the cold pressures and everybody is happy at 30 or so. A couple of days later my wife and I go for a drive down to Monterey and halfway there the left front sensor goes wacky and I get "XX" on the pressure and "Service TPMS" on the DIC. Great.

I realize that it's just the sensor, check the tire pressure with a actual gauge (all is fine) and go on with life until I can get it dealt with.

When I finally find the time to deal with it (new sensor in hand) we take the thing apart and find a CHRYSLER sensor installed in the thing. Wtf??

The interesting part is that rather than not working at all, the system would register 30 pounds one morning, 31 pounds the next, and then sporadically go XX on me.

So the key is not to assume anything 'cause it just might BE 'anything'

Z//

ps. I have Forgeline wheels so the sensors are mounted internally on the rim and not through the normal valve stem exit.

MikeSVT04

^^^interesting story, but mine are all OE sensors. Never been replaced.

BEZ06

The tire pressure sensors send out a digital data stream to the TPMS computer in the car. Like any computerized system, some little bit or byte of data can get corrupted and not work correctly.

You can't use the DIC to set proper tire pressures - you need to adjust tire pressure using a handheld gauge.

After the car sits still for about 15 minutes the sensors go into a sleep mode to save battery strength and they only transmit once per hour.

When you start driving faster than about 20 mph the sensors wake up and start transmitting once every 60 seconds.

If you're not getting proper readings of tire pressures on your DIC, you may be able to get things working again by reprogramming your sensors.

Just FYI to anybody reading this thread, there is one tire pressure sensor required for a 2005-2009 C6, and a different one for a 2010 or newer.

The TPMS computer in a 2005-2009 C6 built for North American delivery has an OE sensor that is gray and is part# 25758220 (cars built for European delivery used a different sensor).



They changed the TPMS computer in the car for the 2010 model year and a 2010 or newer uses a different sensor -actually there are 2 different sensors that will work in those cars.

The 2010 model year cars and a 2011 built in December 2010 or prior came from the factory with a green sensor with part# 15268606.



In January 2011 the factory started installing a black sensor with part# 20925924 - the TPMS remained the same and either the green or black sensor will work in any 2010+ C6.



The gray 2005-2009 sensor requires a TPMS tool that transmits the proper frequency to trigger the sensor to get it to transmit its data to the TPMS computer in the car during the programming procedure.

The green sensor in the 2010 and early 2011 can be triggered by a TPMS tool or by changing air pressure in the tire during the relearn procedure to program the sensors.

The green sensor was also used in the Malibu, Impala, and some other GM vehicles, and if a mechanic was adjusting the tire pressure on a car with green sensors while another mechanic was programming a set on another car, the wrong sensors could get programmed.

So, they changed to the black sensor that can only be triggered by a TPMS tool.

Every sensor has a unique ID# and the TPMS only recognizes transmissions from the 4 sensors that are logged into the TPMS memory.

Only 4 ID#'s can be stored in the TPMS memory, so if you have a couple sets of wheels/tires/sensors such as for the street and track, you need to program the sensors every time you swap wheels - but it only takes a minute with a TPMS tool - a little longer if you have the green sensors and are doing the delta air pressure method.

A 2005-2009 must use the gray sensor (or compatible aftermarket sensor), and the newer cars must use the green or black sensors - you cannot program in a sensor that is not designed to work with the TPMS computer in your car.

The video below shows the programming procedure using a TPMS tool, but if you have the green sensors, after putting the car into the learn mode (ignition to ACC, push both the "lock" and "unlock" buttons on the fob until you get a honk of the horn) you would just let air out (or add pressure) at each tire, making sure you get the confirmation honk at each wheel (double honk at Left Rear).

The ID# of the first sensor programmed in is logged in as the Left Front the second as the RF, the third as the RR, and the fourth as the LR.

If you do the procedure in a different order the sensors will still work, but the DIC report of pressures won't correspond to the actual location of the sensor.

Likewise, if you swap tires from side to side, or get new tires mounted and the sensors get mixed up and end up on different corners than where they were when programmed, they'll still work, but if the DIC says "Right Front 22 psi" it might actually be talking about the LR (or wherever that sensor ended up being mounted).

Also, if you have a low tire pressure, a sensor goes bad on you (they each have a battery in them), you're running without sensors, your sensors aren't programmed in, or for any other reason get the "Service Tire Monitor" DIC message, it may affect your AH system.

Different model years may act a little differently, but in general, if you have one of those things above, you should still be able to turn off TC, but you may not be able to go into Comp mode or turn AH off completely. If you were in Comp or had AH off completely, AH will probably come back full on automatically.

Also, in this so-called "limp mode" individual brakes will come on to straighten out turns if you're trying to corner aggressively and the throttle won't respond until the car is going straight.

All this is to protect you by keeping you from driving aggressively when the TPMS and AH think you have lost pressure in a tire, or if it thinks sensors or the TPMS itself have a problem.

That's why many of us run sensors in our track wheels to avoid AH limp mode problems on the track. It's not as much of a problem for a drag racer, but I can tell you from experience that it's downright dangerous on a roadcourse if you go into limp mode with another car on your tail going into a corner - your car will do things that you and the car behind you are not expecting!!!

Bottom line - the tire pressure sensors are more important to proper operation of the car than many of us realize!

Bob