43
UnclassifiedCooling
What This Code Means
Loss of Speed Sense; Excessive Fuel Pump Prime Time; Coolant Loss; Excessive Smoke Under Load
Possible Causes
- •AC output issues
- •Coolant in oil
- •Cracked or leaking hoses
- •Faulty genset control PCB
- •Faulty local or remote Start/Stop switches
- •Field resistance open, short, or ground
- •Fuel supply issue
- •Fuel supply issues
- •Loose hose clamps
- •Low coolant level
- •Opens, shorts, or grounds in field resistance
- •Opens, shorts, or grounds in quad resistance
- •Overload Condition
- •Quad resistance open, short, or ground
- •Shorted wiring on set & remote
Suggested Actions
- 1Check AC output
- 2Check coolant level
- 3Check field resistance for opens, shorts, and grounds
- 4Check field resistance for opens/shorts/grounds
- 5Check for coolant in oil
- 6Check for cracked or leaking hoses
- 7Check for loose hose clamps
- 8Check for shorted wiring on set and remote
- 9Check fuel supply
- 10Check local and remote Start/Stop switches
- 11Check quad resistance for opens, shorts, and grounds
- 12Check quad resistance for opens/shorts/grounds
- 13Check shorted wiring on set & remote
- 14Check start/stop switches (local & remote)
- 15Evaluate fault codes
- 16Pressure test cooling system (cold)
- 17Pressure test cooling system (hot)
- 18Replace the genset control PCB
ASK RUDY ABOUT THIS FAULT
Get a diagnosis walkthrough for 43 on your specific Onan unit — cited to the OEM manual, not a forum guess.
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