I was driving the other day and got a service tire system code error. it showed Rear Rxxx on the gauges. It went away after a day or so but i was just wondering what might of caused it? The temp outside was 103 degrees on that day, probably making the pavement astronomically hot. Could this heat have thrown the sensor?

 

I doubt it, tires get significantly hotter than surroundings, that is why the air pressure increases when you drive. Temperatures inside tires are usually 40 degrees higher than outside temperature.

Could have been some malfunction. The motion sensor (which saves battery life) could have stuck in the off position. If this happens again, try driving over some railroad tracks.

 

Tire pressure monitor is probably on its way out.
I had one RR go out and it froze the whole system. None of the other pressures would change. Then by chance I got a flat in the RR and didnt even realize it for a day (stiff azz run flats).

 

Yep, most likely the battery in one (or more) of your Tire Pressure Sensors is dead or dying. You can try programming the TPS. You'll need a magnet - I use a veterinary magnet like they use to treat "hardware disease," and just program as follows (from the Hunter tire service equipment website...)

Receiver Programming
The receiver is programmed at the factory to recognize which sensor is at each wheel location. If tires are rotated or a sensor is replaced, the receiver must be reprogrammed, following SI procedures.

If the receiver is not reprogrammed, the system will continue to report the correct pressures, but will assign them to the wrong locations on the vehicle.

TIP: There are two reprogramming methods. You must use the J-41760 magnet when a new sensor is installed. During tire rotation, you can use either the magnet or your Tech 2.



J-41760 Magnet can be replaced by any relatively large, strong magnet held parallel to the valve stem and circulated around the stem slowly until you get the chirp mentioned...

Magnet Method
You will have only one minute between horn chirps, and five minutes overall, to complete the procedure once you start.

With ignition on, engine not running, press both lock and unlock buttons on the key fob. A horn chirp within 10 seconds indicates that the receiver is in programming mode.

At each wheel, hold the J-41760 magnet over the valve stem until the horn chirps, to force the sensor to transmit its code. You must follow this order: LF, RF, RR and LR. The horn chirps twice to indicate completion.

Scroll through the DIC readout to verify all four pressures are displayed.