No COMM From Any Board to Main Micro
system
Description
The main microprocessor cannot communicate with any modules over the CAN bus, and the unit shuts down and alarms.
Activation Conditions
Main microprocessor cannot communicate with any modules over the CAN bus.
Unit Behavior
Shutdown and alarm. Display module may display “LOSS OF COMMUNICATIONS”.
Reset Conditions
Auto reset when CAN communication is restored, or alarm reset or Alarm may be manually reset by turning the unit off, then back on again.
Corrective Actions
1. Check CAN Bus a. Inspect connector pins and terminals on 1MM, 1SVM, DM and ENCU. Verify no damage or corrosion in connections. b. Check for CAN continuity: CAN Hi; 1MM-2 through SP-1 to 1SVM-5 and ENCU-23 and 1SVM-2 and DM-2. CAN Lo; 1MM-4 through SP-4, to 1SVM-7 and ENCU-24, and 1SVM-4 and DM-6. Check for good continuity. If not, check connectors and wiring between terminals. Verify no damage, moisture or corrosion. 2. Check for other CAN Bus Alarms: This alarm may accompany by other alarms, complete troubleshooting steps for alarms found. If repairs have been made and the other alarms have cleared, further troubleshooting may not be required. If this alarm reoccurs, check CAN bus as described in the proceeding step. 3. Perform and Analyze a Data Download