Onan HGJAB Service Manual

11-15
GOVERNOR ACTUATOR OVERLOAD (EFI ONLY) – FAULT CODE 22
WARNING
Some genset service procedures present hazards that can result in severe personal injury
or death. Only trained and experienced persons with knowledge of fuels, electricity, and machinery
hazards should perform genset service. See Safety Precautions.
Logic: Only active Prior to 2001 – Maximum governor output (PWM) for 10 continuous seconds
Possible causes: Genset loads, Inverter/Charger, wire connections, fuel supply, air fuel mixture, exhaust
system, governor actuator, ignition system
Diagnosis & Repair:
1. Verify that Last Fault is FC 22: Yes, continue diagnosis; No, troubleshoot actual last fault.
2. Measure AC current while running genset with vehicle loads: identify faulty or short cycling loads or re-
duce vehicle loads as necessary.
3. Determine battery charge rate (typical default is 80 percent): if adjustable reduce to 30 percent.
4. Measure genset load capability with shop load bank (derate for altitude and temperature as necessary).
5. Measure AC frequency and droop while running.
6. Measure AC frequency while changing engine rpm to determine if frequency response matches engine
rpm response: repair damaged generator drive system as necessary.
7. Disconnect genset control P1 connector, verify P1 pins are fully inserted and inspect pin condition per
PSB–676: insert, repair or replace pins as necessary.
8. Reconnect P1 connector and test run genset for fault occurrence: repair or replace pins in connector as
necessary.
9. Check air filter cleanliness; replace air filter as necessary.
10. Check intake manifold and gaskets for air leaks: tighten fasteners and replace gaskets and manifold as
necessary.
11. Check for blocked or damaged exhaust system: repair or replace exhaust components as necessary.
12. Measure fuel pump pressure/flow: replace fuel filter, pressure regulator or fuel pump as necessary.
13. Verify actuator function by applying DC voltage to terminals: replace actuator as necessary.
14. Check throttle body for binding; inspect spring for dirt and debris: clean spring, replace throttle body as
necessary.
15. Verify that spark plug cables are secure on spark plugs: reconnect or replace as necessary.
16. Inspect ignition kill leads in harness and at connector P1: repair or replace lead, terminal or pins as neces-
sary.
17. Test Magnetos:
A. Disconnect Connector P1.
B. Connect positive(+) meter lead to chassis ground.
C. HGJAA, D, E, F – Measure continuity to negative lead at pin P1–4 and P1–5: replace magnetos as
necessary.
D. HGJAB, C – Measure continuity to negative lead at pin P1–15 and P1–20: replace magnetos as nec-
essary.
18. Measure spark plug gap: set gap or replace spark plugs as necessary.
19. Verify ignition spark condition.
20. Inspect spark plug cables, kill lead terminal at magneto and measure magneto air gap: replace terminals,
set gap or replace magnetos as necessary.
21. Dealers contact Distributor for technical support, Distributors contact factory for technical support.

Onan HGJAB Specifications

General

Brand	Onan
Model	HGJAB
Category	Portable Generator
Language	English