I hope someone can shed some light on an issue I'm having with my 2 week old 03 M3 convertible with 56k miles. (no SMG) This car does not have traditional TPM sensors and figures tire diameter through the ABS wheel speed sensors. Apparently it looks for a change in wheel speeds, indicating a deflating tire. I have no ABS, DSC/TC lights, but the tire pressure light comes on after about 10-15 minutes of driving. All pressures are at 40 PSI, the mid range between lightly and fully loaded pressures on the door jamb. I've had them at min and max pressure too. Any ideas on what to look for? Thanks so much for helping! Jeff S52 powered 88 M3 tribute cabrio 03 M3 12 K1600GT
Have you done the reset procedure in order for the system to measure the tires rotation rates. To do this leave the key in the on position with out starting the engine. Push and hold the tire button until the yellow tire light flashes or off depending on if it was on already or not. Once that happens release the button then press and hold the button again until the tire light comes on in yellow. Then without turning the key off start the car and drive until the tire light goes off. The system has been reset and relearned properly.