No COMM From Micro to ENCU
engine
Description
No COMM From Micro to ENCU means the Microprocessor Stepper Module cannot communicate with the engine control unit over the CAN bus; shutdown and alarm.
Activation Conditions
Microprocessor Stepper Module cannot communicate with the engine control unit over the CAN bus.
Unit Behavior
Shutdown and alarm.
Reset Conditions
Auto reset when CAN communication is restored, alarm reset or alarm may be manually reset by turning the unit off, then back on again.
Corrective Actions
1. Check Both Active and Inactive Alarms for other “NO COMM” Alarms a. If more than one alarm, record all and proceed to step 2. b. If this is the only alarm, check for continuity: CAN Hi: 1-2MSM-27 to SP-26 to ENCU-66 CAN Lo: 1-2MSM-28 to SP-27 to ENCU-65 c. Replace ENCU. 2. Check CAN Bus a. Inspect connector pins and terminals on 1MM and1SVM. No damaged or corrosion in connections. b. Check for CAN continuity: CAN Hi: 1-2MSM-27 to SP-26 to ENCU-66 CAN Lo: 1-2MSM-28 to SP-27 to ENCU-65 If good continuity is not present, check connectors and wiring between terminals for damage, moisture or corrosion. 3. Check System: Clear active and inactive alarms. Start unit and monitor for additional “NO COMM” alarms.