Check the green Phoenix connectors on the back. This usually means the ICU cannot "see" the exterior LED boards.
Do not turn off the power until the screen displays "Update Successful." 4. Troubleshooting Common Errors If the unit isn't behaving, check these common fault codes:
Check the 24V fuse in the vehicle's electrical locker. The ICU 602 is sensitive to voltage drops during engine cranking. 5. Technical Specifications for Installation mobitec icu 602 user manual repack
For technicians looking to wire the unit, here is the standard pin-out logic: +24V DC (Red) and Ground (Black). Communication: A/B pair for RS-485 or WB/WA for IBIS.
Use the arrow keys (Up/Down) while on the home screen to manually override the sign brightness, though most ICU 602 units use an integrated light sensor for automatic dimming. 3. Advanced Settings & Programming Check the green Phoenix connectors on the back
If you are "repacking" the software or updating the route list:
Some models require a 24V signal to the "Ignition" pin to wake from sleep mode. Troubleshooting Common Errors If the unit isn't behaving,
The data file is corrupted. You need to re-format your USB and reload the destination files.