Onan Generator: “Fault 19”
warning RV generator fault codes
What it means
Governor actuator fault. The controller detected an open or shorted circuit in the electronic governor actuator that regulates engine speed.
Most likely causes
- Open or short in the governor actuator or its wiring most likely
- Failed governor actuator common
Safe checks you can do yourself
- Visually inspect for obvious damaged or disconnected wiring near the governor actuator (with the generator off and battery negative disconnected).
- Note the code and how often it recurs to help the technician.
How to reset / clear Fault 19
- This is a dealer-service fault; no owner reset clears the underlying cause.
When to call a technician
Whenever Code 19 appears — the manufacturer directs this to an authorized Onan dealer.
Accuracy notes
Documented on the liquid-cooled Quiet Diesel sets, which measure the actuator circuit at startup; the manual gives 2.8 to 2.9 ohms across the actuator leads as the expected resistance. Do not confuse it with code 22, which is a healthy actuator held at full duty cycle by too much load — that one is fixed by the operator, this one by a dealer.
Applies to
Marquis Gold · QG 4000 · QG 5500 · KY series · HGJAA · HGJAB · HGJAC · HGJAD · HGJAE · HGJAF
FAQ
What does Onan Generator code "Fault 19" mean?
Governor actuator fault. The controller detected an open or shorted circuit in the electronic governor actuator that regulates engine speed.
How do I reset Onan Generator Fault 19?
This is a dealer-service fault; no owner reset clears the underlying cause.
What is the most common cause of Fault 19 on a Onan Generator?
The most likely cause is open or short in the governor actuator or its wiring.
Related · Onan generator
Governor actuator overload. The controller had to hold the governor… Fault 15
Underfrequency fault. The engine governor could not keep the engine…
Sources
- Onan Troubleshooting Codes (Service Manual Table 5) — Governor Actuator Fault — Code No. 19 (Cummins Onan (hosted by Heartland Owners))
- Operator Manual — RV Generator Set HDKCA / HDKCB (Spec A–E) — 0981-0173 (Issue 10), Section 4 Troubleshooting, Table 4-1 (Cummins Inc. (Onan Quiet Diesel))
● Checked against 2 manufacturer documents · Last verified 2026-08-07 · compiled from manufacturer documentation. Codes can vary by model year — always cross-check your unit’s manual. How we verify