The TPMS indicator

WARNING: This page is about a different car, the 2009 Acura MDX, 2008 Acura MDX, and 2007 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

If a problem in the system is detected, the TPMS indicator come on, as well as the message indicator.
If low tire pressure and a problem in the system are detected, the TPMS indicator comes on, as well as the message indicator.

If the system is OK, the low tire pressure indicator should come on when you turn the ignition switch to ON (II), and then go off 2 seconds later. If it doesn't, there is a problem with the system.

If a problem is detected in the system, most DTCs will cause the TPMS indicator with the message indicator to come on and stay on until the system returns to normal. If DTC 45, 61, 63, 65, 67, 81, 83, or 85 is set, the TPMS indicator will go off only when the ignition switch is turned to LOCK (0).