service tire pressure monitor system?
 

I have a 2004 mn6 mag red coupe with 20k miles. It has been sitting for three weeks because of the weather. I fired it up today and got low tire pressure warning on LF and LR tires after I had run down the road a ways. I figured that the cold weather had lowered the pressure a bit and sure enough, after driving for ~ 10 min the low tire warning dissapeared.
Tonight,I drove it again after it has gotten colder (22 F) and I first got low tire warnings on the same wheels but it now is flashing back and forth between LF and RF . Also the heads up is showing "Check Gauges " message. I then stopped and aired up the tires to 30 psig. I still got the same low pressure messages. After driving 20 min, I got the service tire pressure system message.
Do I need to reprogram my sensors? I have the dervice manual but no scan tool. Where do I start?

Take your tire pressure up to 35 psi... the cold ground will lower the intenal temps and you will be fine.. you get a warning at 25 psi... if the tires are warm when you add air you need to check the air pressure when warm.... so that when they sit they will go under the lov pressure limit. so go and put 35 psi in them.

If you need to reset the tire pressure monitors...
 

....do this:
1) Turn ignition on 2) Press "Reset" button in order to clear any IPC display warning messages 3) Press and release the "Options" button on the DIC to scroll through the display options until the IPC display is blank 4) Press and hold the DIC "Reset" button for 3 seconds 5) Press the "Options" button again until TIRE TRAINING message appears 6) Press "Reset" button until the IPC "Learn L Front Tire" message appears in order to begin the programming 7) Install the J41760 Tire Pressure Monitor (TPM) System Programming Tool (large magnet will do) over the left front valve stem 8) The horn will sound, indicating the left front TPM sensor is programmed (if this takes more than 15 seconds, pull magnet back and try again, it will give you three tries. Then you must start over) 9) When the horn sounds, proceed to program the next TPM sensor in the following order as directed by the IPC messages: -Learn R Front Tire -Learn R Rear Tire -Learn L Rear Tire Programming can be canceled by turning ignition off, waiting 2 minutes with no sensors being learned, finishing all 4 wheels or through the DIC. If the programming is canceled with less than 4 sensors learned, it will only accept the codes programmed up to that point.

The Tire Pressure units in the tires have a small radio transmitter in them. They transmit 2 pieces of data ... the tire pressure, and the units unique serial number.

The radio transmissions are picked up by the RFA (Remote Function Actuator) which is a radio reciever that also picks up the transmissions from your key fobs. The data is then sent to the BCM from the RFA, and the BCM has the software that displays/alarms the tire pressure data.

When you move tires around on the car, and then go into TPMS "training" mode, the BCM displays a message to train the LF tire. The magnet you put near the tire stem wakes up the sensor and it transmits its serial number and tire pressure. The BCM then internally stores the information that that particular unit (serial number) is at the LF position. As you go round the car training the system, the BCM is simply "learning" the serial numbers of the sensors, and where they are located.

When the wheels stop turning, after a few minutes, the sensors go to "sleep" to conserve their internal batteries. When the wheels start turning again, the sensors wake up and start transmitting their serial number and pressure again. I believe they transmit several times a minute until the car has been stopped for a number of minutes (like 15 to 20).

Well, I drove it this morning and everything is working normally. I guess adding air up to 30 PSIG fixed it. I just don't understand why it didn't respond last night. Maybe it just didn't like the cold. It is a "Southern" car after all!

Question for you: I recently got an error on my 99 vette regarding the rear right tire not reading pressure right. So last night I bought a magnet at a local hardware store, printed out those instructions and went to reset tire. Started with front left, no prob, got the horn, moved over to front right and nothing. Tried again for about 15-20 minutes and everytime I couldn't get past that tire in the sequence. And that's not even the one having problems......

Thoughts?

Programming Cancellation
1. The programming mode will be cancelled if any of the following conditions are met: - The program mode is exited through the DIC.
- The ignition is turned to OFF.
- All four sensors have been programmed.
- The TPM system has been in the program mode for longer than 2 minutes and no sensors
have been learned.
2. If the program mode is cancelled with less than four codes stored, the receiver will only accept the codes programmed up to that point

But the problem is the magnet won't reset that tire, it's not a time out issue.

Sounds like this TPM's battery is dead or the unit itself needs replacing. Is it giving you a psi readout when you check the R front tire pressure on your DIC? Life of a TPM is 6 to 8 years.

Yes that's what's weird...The Right Rear tire wasn't giving me a reading and was the tire setting of the DIC alarm. So I thought I'd reset all of them with a magnet to make sure it was really dead. Last night when I tried it I couldn't get past the Right Front tire in the sequence which like I said was weird since it wasn't giving me a problem. Now of course since I only got through the Front Left tire, only that one is giving me a reading. I'm going to try again tonight and hopefully I can do all 4 tires in the sequence.

Have the same problem on TPM sensor
 

Used a strong magnet and got the first tire to chirp but not the second one. redid and notice no timeout menu was still up. suggestions?

tms
 

I have a similar problem with my 99, Lf sensor was bad , other 3 worked, replaced lf sensor & discount tire activated, lf, other 3 did not display , now reprograming does not wok even with the tool , tried magnet it no work ethier, any suggestion? GRR

I tried tried the tool, didn't work. took it to the dealer, what a mistake. Told me I needed a new reciever for the car, not the one in the wheel. Laughed that off. My son blew his subwoofer up. Used the magnet from that. They all programmed fine with that huge magnet. No problems since.

I guess that 45 day rule on old posts is more of a suggestion than a rule.