Alternative way to enter diagnostics mode (instead of the ENABLE_DIAGS file)?

In an attempt to make my fourth partition ext3 (the one usually mounted to /mnt/us), I broke the system's ability to read or write to it, which also broke my SSH connection to it somehow (even though sshd lives in /usr/sbin/sshd as a file, not a link to /mnt/us/usbnet/...).

Long story short, is there a way to enter diagnostics mode without access to this parition? I cannot write the ENABLE_DIAGS file at this time.