Without Scan Tool
WARNING: This page is about a different car, the 2004 Acura 3.5RL, 2003 Acura 3.5RL, 2002 Acura 3.5RL, and 2001 Acura 3.5RL. However, it is still accessible from the selected car via links, so may be relevant.
To clear PCM memory without using a scan tool, remove No. 56 BACK UP RADIO (7.5-amp) fuse from underhood fuse/relay box for 10 seconds.