Does the TPMS warning light go on when you first turn the key to start and all the instruments lights turn on as a test just before starting the engine? It is located on the left side at the top of the other warning lights. If it's not showing then a previous owner disengaged it. It will never light if the GY/YL wire in the overhead cabin light has been moved from it's number two position on the connector to the blank number 6 position. See post #3 click here