Service Manual

7. Troubleshooting 10-2019
144 A062J683 (Issue 1)Copyright © 2019 Cummins Inc.
• Faulty control board
• Faulty starter
Diagnosis and Repair:
1. Attempt to replicate the fault.
2. Measure the battery voltage at the battery, at the generator set, and at
connector P1.
• Reconnect, clean, repair, and replace connections as necessary.
3. Measure the battery voltage at the generator set while starting
from the local or remote display.
• Recharge or replace the battery if the voltage drops below 8 VDC.
• Test and service the generator set battery charger.
4. Inspect the starter:
a. Verify B+ at the positive battery terminal of the starter.
b. Verify B+ at the positive terminal of the starter solenoid
while attempting to crank.
c. If the battery has been verified as good, replace the faulty starter.
5. Inspect the condition of the control board P1 and P2 pins. If they are damaged
or severely corroded, clean or repair them if possible, or replace the control
board.
6. Reconnect the P1 and P2 connectors. When reconnecting the harness to the
connector, make sure that the pair are fully seated next to each other.
7. Test-run the generator set for start operation.
8. Disconnect the generator set control P1 and P2 connectors.
9. Verify that the P1 and P2 pin sockets are 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 any pin sockets.
• Fully insert any partially inserted pin sockets.
Starting Battery Runs Down or Low Battery Warning Is
Active
Logic: Low or no battery voltage, or Low Battery Voltage Warning