Service manual

9-2013 9. Troubleshooting
22. Inspect the spark plug leads, kill lead terminals at magnetos, and measure the magneto air
gap: replace the terminals, set the gap, or replace the magnetos as necessary.
9.21 Voltage Sense Lost - Fault Code 27
Logic: generator set frequency is greater than 40 Hz and voltage sensed less than 5 VAC on
one or both lines. (The control senses if one line is lost or disconnected).
Possible Causes: generator set loads, generator windings, ignition, wire connections,
Diagnosis & Repair:
1. Verify that the Last Fault is FC 27: Yes, continue diagnosis; No, troubleshoot actual last
fault.
2. Measure AC voltage.
3. Disconnect the generator set control J1 connector, verify the J1 pins are fully inserted, and
inspect pin condition using the steps below:
• Use the test points of the tester tool #420-0603
• Use a mating pin connector, a pin gauge of the same size (.045") as the mating
control connector pin, or any suitable device that will not damage the inside contact
wipers of the pin socket
• Insert, repair, or replace pins as necessary.
4. Reconnect the J1 connector and test run the generator set for fault occurrence: repair or
replace pins in the connector as necessary.
5. Measure field, quadrature, and main winding resistance: clean the slip rings, replace the
brushes, repair the harness, and replace the rotor or stator as necessary.
6. Measure field, quadrature, and main winding resistance to ground: clean the slip rings,
replace the brushes, repair the harness, and replace the rotor or stator as necessary.
7. Measure field, quadrature, and main winding resistance to each other: clean the slip rings,
replace the brushes, repair the harness, and replace the rotor or stator as necessary.
8. Check brush alignment.
9. Verify that the spark plug cables are secure on the spark plugs: reconnect or replace as
necessary.
10. Inspect the ignition kill lead (J1-12) in the harness and at connector J1: repair or replace
the lead, the terminal, or the pins as necessary.
11. Measure the spark plug gap: set the gap or replace the spark plugs as necessary.
12. Verify ignition spark condition.
13. Inspect the spark plug leads, kill lead terminals at magnetos, and measure the magneto air
gap: replace the terminals, set the gap, or replace the magnetos as necessary.
14. Measure temperature of the air intake and temperature rise across the generator set;
remove blockage or prevent air recirculation.
9.22 High Battery Voltage - Fault Code 29
Logic: DC voltage to controller greater than 19 VDC.
A030A239 (Issue 10) 99