From 97 Expedition WSM:
THEFT Indicator ON two seconds, then flash for one minute, then flash diagnostic trouble code 16 ten times.
Key Code Received/Vehicle Enabled or Disabled (No PCM Verification).
If vehicle starts, PCM is not working with control module.
If vehicle does not start, refer to the Module Communications Network section.
Refer to Section 418-00 for diagnostic assistance to isolate any communication system.