Service Manual

7. Troubleshooting10-2019
157A062J683 (Issue 1) Copyright © 2019 Cummins Inc.
• Automatic Transfer Switch (ATS)
Diagnosis & Repair:
1. Check the last fault recorded.
• If this fault has not been repaired, troubleshoot that fault.
2. Measure and verify governor actuator resistance (2.8 Ohms ±5%).
• Replace if necessary.
3. Measure and verify governor wiring to the control.
• Replace or repair if necessary.
4. Disconnect the generator set control P1 connector.
5. 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 used 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.
6. Inspect the condition of P1 pin on the control board. If it is damaged or severely
corroded, clean or repair if possible, or replace the control board.
7. When reconnecting the harness plug to the connector, ensure that the pair are
fully seated next to each other.
8. Reconnect the P1 connector and test-run the generator set for fault occurrence.
9. If the same fault occurs after retesting the governor actuator, the problem may
reside in the ATS.
a. Verify all ATS connections (J2-4/TB4-1 and J2-3/TB4-7) are connected
properly.
b. Verify that the ATS jumper between TB4-3 and TB4-4 is connected.
c. Verify the ground connection at TB4-4.
d. Retest the generator set for any fault conditions.
Code 22 - Governor Actuator Overload
Logic: Maximum governor output (PWM) for 10 continuous seconds
Possible Causes:
• Generator set loads
• Wire connections