# Cummins Onan RV Generator code 45



## sinecure (Jan 7, 2017)

Hi,

I have a 2013 RV with a Cummins Onan RV QG 5500 EVAP gasoline generator, with 45 total hours. New battery.
Model #: 5.5HGJAB-6755J
Serial #: D120326173

The generator will start and immediately shut down. If it start it again, the engine will run (and sounds fine) but it must be in a fault mode because it will not power anything in the RV. If I shut it down and restart, the process of shutting down immediately and running in fault mode repeats again.

When the generator first starts and shuts down, the diagnostic light flashes 3 times, which indicates a "service fault".
I press "stop" and the specific code 45 flashes, meaning "Speed Sense Fault" (Controller unable to sense quadrature frequency).

I'm fairly technically and mechanically inclined, but new to this generator with all it's electronic controls. I was hoping someone familiar with these generators could give me an idea on which parts I should start with to test and/or replace.

Thanks in advance!


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## RonJ (Aug 5, 2015)

While we wait for an input here, you might check out RV.NET...since your generator is RV specific, you might get a fast response to the Code.


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## repairroth (Aug 21, 2019)

Have you found a fix for this fault code? I have the same problem.


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