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dchou1107
07-25-2005, 01:59 PM
When I was driving yesteday all of a sudden message stating SERV TPM came up on my odometer. It then went away and came back about 10-15 min later. Today I did not get a message at all. What is this sensor?

dchou1107
07-25-2005, 01:59 PM
When I was driving yesteday all of a sudden message stating SERV TPM came up on my odometer. It then went away and came back about 10-15 min later. Today I did not get a message at all. What is this sensor?

f5fstop
07-25-2005, 03:18 PM
Basically, it means there was a problem in the tire pressure monitoring system. This system monitors the air pressure in your tires, and if the tires drop below, or go above a calibrated pressure reading the system will notify you so you can attend to whatever tire is low.
If a tire is low, the message is Check Tire Pressure, for your message, there was a problem in the actual system (which consists of sensors in each tire, powertrain control module (PCM), body control module (BCM), and IPC/DIC (instrument panel cluster/driver information center).
If it does not reappear, just blame it on some sort of momentary glitch in the system. If it does reappear, a dealer visit is necessary.

Hummer4Life
07-25-2005, 09:50 PM
Mine started coming on after I put aftermarket wheels on. I'll probably have the dealer simply turn it off.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by dchou1107:
When I was driving yesteday all of a sudden message stating SERV TPM came up on my odometer. It then went away and came back about 10-15 min later. Today I did not get a message at all. What is this sensor? </div></BLOCKQUOTE>

f5fstop
07-25-2005, 10:45 PM
The sensors will work with aftermarket wheels. If the sensor won't fit through the tire valve hole and install as originally designed, it can be epoxied and strapped in place around the inside of the wheel.
The sensors are specific to each corner of the vehicle. When switching rims, it is a good idea to place the same sensor at the same corner. However, this new system GM is using has a self-learning mode, that will allow it to learn the sensors location over a driving period. During that driving period you will receive some DIC messages. The self-learn method is what is used if you have to use a spare, since the spark also has a sensor.
The sensors can also be forced learned using a special low frequency tool. (The older version required either a magnet to open a reed switch or a low frequency tuner to allow the BCM to recognize each sensor.)
This is one system that is nice to have, in that if one of your tires starts to loose pressure, you will be warned (unless a complete tire failure when the tire is blown). It works great when you pick up a nail, and sometimes can help prevent you from having to change a tire at the side of the road.
Just a thought.

H3Lady
07-26-2005, 12:17 AM
On my other cars we that have this, there is a reset in the glove box.

is there a reset in the h3 for the monitors. Like after a new tire or air added.

Hummer4Life
07-26-2005, 01:41 AM
Thanks f5fstop. Although I really don't think I could do what you described myself, and the more I think about it, I probably won't do any correcting of the sensors now, because I'll be switching back to my factory wheels in the winter each year, at which time I assume the sensors will work again.

H3Lady, the reset is done by pushing the odometer reset button briefly when you see the message.

dchou1107
07-29-2005, 11:01 AM
my message appears and then it is gone. It states low tire after I turn the lights on three times according to the manual. I took it to the dealer and then on the way home the message reappear. Please advise. I will also check the tire pressure on the spare tire as well.

f5fstop
07-29-2005, 04:41 PM
Not sure if this is your problem, but it is a problem for many people.
The system is set to signal a low tire if the reading drops below 25-26 psi. So, let's say at night you have one tire that is reading about 28 psi, and overnight, the temperature drops 20 degrees, the next morning when you start the vehicle, the system may determine you have a low tire. Every 10 degree drop in air temp, drops the tire pressure by 1 psi. So, at night you have 28 psi, but in the morning you have 26 psi.
Now, you drive to the dealer, starting with the tire at 26 psi. However, the tire warms, the pressure goes up, and bingo, the message goes away. The system is not smart enough to know the increase in pressure is due to driving, it assumes you added air.
So, I would check the pressures on cold tires that have been parked in the shade (Cold tires=tires that have not been driven for over three hours.) Then adjust the tire pressure in the tires to match what they should be per the tire placement label.
Again, make sure one side of the vehicle is not in direct sunlight. Sunlight directed on the tire can cause the air pressure inside to increase by up to 3 psi, depending on the condition.
This is a large problem facing many auto manufacturers today and will become larger as more tire pressure monitoring systems are added due to Federal regulation. For years, many customers have never checked their tire pressure, and they do not understand the relationship of tire pressure versus heat/cold cycles. Dealers are swamped some mornings with customers who drive in with a message that one of their tires, or all of their tires are low in pressure.
Again, I'm not saying this is your problem, but it is a large problem with the population at large.
If this is not your problem, then I can't say. Impossible to troubleshoot an electrical problem without being there.