Service Manual

7. Troubleshooting 10-2019
158 A062J683 (Issue 1)Copyright © 2019 Cummins Inc.
• Fuel supply
• Air fuel mixture
• Exhaust system
• Governor actuator
• Ignition system
• Elevated ambient temperature
• Cooling air flow blockage
Diagnosis & Repair:
1. Check the last fault recorded.
• If this fault has not been repaired, troubleshoot that fault.
2. Open the generator set circuit breaker so no load is on the product and run the
generator set.
• If the same fault occurs, troubleshoot the actuator control or fuel system.
• If no fault occurs, check the loads from each individual circuit to determine
the total load on the generator set. Determine if the total load amount
exceeds the capacity of the unit.
3. Measure the AC current while running the generator set with loads.
• Identify faulty or short cycling loads.
4. Measure the generator set load capability with load bank; de-rate for altitude
and temperature if necessary.
5. Disconnect the generator set control P1 connector.
6. Verify that the P1 pin socket is fully inserted and inspect the pin socket
condition for corrosion and acceptable condition of contact wipers. To check
contact wipers, use one of the devices below:
• A mating pin connector
• A pin gauge the same size as the mating control connector pin (0.045 in)
• Any suitable device that will not damage the inside contact wipers of the
pin socket
If necessary:
• Clean, repair or replace the pin socket.
• Fully insert any partially inserted pin socket.
7. Inspect the condition of the P1 pin on the control board. If it is damaged or
severely corroded, clean or repair if possible, or replace the control board.
8. When reconnecting the harness plug to the connector, ensure that the pair are
fully seated next to each other.
9. Reconnect the P1 connector and test-run the generator set for fault occurrence.