Acura 3.5 RL Manual page 1397

Description
SRS Airbag System - '99 - 01 Models (cont'd)
Self-diagnosis System
A self-diagnosis circuit is built into the SRS unit; when the ignition switch is turned ON (II), the SRS indicator light comes
on and goes off after about 6 seconds if the system is operating normally.
If the light does not come on, or does not go off after 6 seconds, or if it comes on while driving, it indicates an abnormality
in the system. The system must be inspected and repaired as soon as possible.
For better serviceability, the SRS unit memory stores the cause of the malfunction, and the unit is connected to the data
link connector (DLC). This information can be read with the Honda PGM Tester when it is connected to the DLC (16P).