Cummins/Onan MCE Engine

How to read your Cummins/Onan engine serial & model number →

• Low Battery, Generator Set Does Not Recharge
  Cause: 1. Weak or discharged battery. 2. Load connected to battery while set is turned off. 3. Generator set not run long enough for built-in charger to recharge battery. 4. Defective VR2 voltage regulator. 5. Defective stator winding (B1 -B2).
• Engine Starts But Stops When Start Switch is Released
  Cause: 1. Fault condition. 2. Defective Fault Sensor. 3. Defective relay on engine monitor PCB (A1 1). 4. Defective fault circuit breaker CBI 2. 5. SOVAC not present across AC terminals of engine monitor PCB (A1 1) because of: A. Defective flash diode CR1 B. Defective generator
• Engine Does Not Crank
  Cause: 1. Control fuse F11 open. 2. Insufficient voltage for cranking due to: A. Terminal connection loose or corroded. 6. Battery dead or not charged 3. If engine cranks at set but not at the remote control panel, cause may be: A. Open circuit in remote B. Fault with remote start control switch. 4. If engine cranks at remote control panel but not at set, cause may be: A. Open circuit in wiring B. Fault in S11 switch between S11 switch and engine monitor PCB (A1 1). 5. There is voltage at terminal S, but not at S1 of starter solenoid K11 during START. 6. There is voltage at the starter motor terminal during START. 7. There is no voltage at terminal S of starter solenoid K11 during START.
  Fix: 1. Replace fuse (10 ampere) A. Clean and tighten connections at battery, K11 start solenoid, and the starter motor. B. Check condition of battery and recharge or replace. 3. A. Check for continuity and correct if circuit is open. B. Replace remote start switch. 4. A. Check for continuity and correct if circuit is open. B. Replace S11 switch. 5. Check voltage at terminal 1 of solenoid K11. If it is not “0”, fix lead to ground. If voltage at terminal 1 of solenoid K11 is “0, replace faulty solenoid K11. 6. Service or replace defective starter. 7. Fix open circuit between K11 and engine monitor PCB (A1 1). If OK, replace defective engine monitor board (A1 1).
• Engine Cranks But Does Not Start
  Cause: 1. Faulty ignition due to defective spark plugs, plug wires, coil, or electronic module. 2. Faulty fuel system due to sticking choke, faulty fuel pump, plugged filter, or carburetor misadjustment 3. There is no voltage at igniter coil or fuel pump positive terminal.
• Engine has a number of sensors that continuously monitor it for abnormal conditions such as low oil pressure, high coolant temperature, and high exhaust temperature.
  Fix: The Fault Breaker is a manual reset breaker that shuts down the engine for these conditions.

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan MCE.

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.