DTCS Continuously Displayed: Description
WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
When Data Link Connector (DLC1) terminals Tc and E1 are connected together, air bag sensor assembly is set in Diagnostic Trouble Code (DTC) output mode. DTC is displayed by blinking AIR BAG warning light.