First Alert FA142C Installation Instructions Manual page 26

3. Fault and restore every contact or sensor in each expansion zone
individually to ensure that it is being monitored by the system. Each time a
zone is faulted, the keypad should display the number of the faulted zone
(as programmed by you just previously in 56 mode). When each zone is
restored, the READY TO ARM message should appear again.
4. When you get the proper displays on the keypad(s), the wired expansion
zones in the system are functioning properly.
5. Unplug the AC transformer.
If a "CHECK 09" message appears on the display, data from the control is not
being received by the zone expander module. Check your wiring and DIP
switch settings.
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