Error code 1603-underspeed
I have a generac 22kw evolution home generator. It is natural gas with a transfer switch. I have it set to run for 30 minutes once every 2 weeks. Lately, I have been getting an error code 1603-underspeed. It is 1.5 years old. I can't seem to find any material on the solution to the problem. Does anyone have thoughts?
The first odd thing I notice is that these won't run 30 minutes for an exercise, only 5, and that duration isn't changeable.
The underspeed is telling you that the engine isn't running fast enough. That is usually fuel related or a stepper motor issue. When you put the unit into Manual mode, do you see the throttle sweep back and forth before it cranks?
The underspeed is telling you that the engine isn't running fast enough. That is usually fuel related or a stepper motor issue. When you put the unit into Manual mode, do you see the throttle sweep back and forth before it cranks?
Generac tech for over 12 years. I'm here to help!
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Hello,
I also have the same error message/ problem. Motor starts and runs for a short period of time at a low RPM and then shuts off displaying under speed error message.
My stepping motor does actuate throttle linkage moving it back and forth just prior to starting.
Any assistance regarding what could be causing this under speed would be greatly appreciated!
Unit has been working fine since I installed it a few years ago until recently when this problem developed.
I also have the same error message/ problem. Motor starts and runs for a short period of time at a low RPM and then shuts off displaying under speed error message.
My stepping motor does actuate throttle linkage moving it back and forth just prior to starting.
Any assistance regarding what could be causing this under speed would be greatly appreciated!
Unit has been working fine since I installed it a few years ago until recently when this problem developed.
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grsthegreat
- Generator Jedi Master
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- Joined: Mon Apr 20, 2020 5:59 pm
Dies this happen when exercising, or when running it in manual or during a power outage?
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Goodwin3973
- New Member
- Posts: 4
- Joined: Sat Jul 18, 2020 1:54 pm
I have a similar issue, it doesn't give me a code but it does say underspeed.
17kw generac Genie ,model#OH4655, 992cc, ser# E8854052 13073. shut down right away and said "underspeed". This is the second time i have come and found nothing wrong but customer has experienced a shutdown pretty quickly after call for electricity and startup. Giving an alarm "underspeed".
Tested fuel pressure, hertz and stepper motor. Cycled on/off several times while monitoring fuel pressure/hertz and sound. All good.checked connector for stepper and visionally saw it function. Also confirmed no real loads where present at time of alarm. I loaded it and tested all good. This doesnt happen when i am here and during maintenance cycle. There has been a code for check battery at each maintenance cycle.
I appreciate any help.
Tony
17kw generac Genie ,model#OH4655, 992cc, ser# E8854052 13073. shut down right away and said "underspeed". This is the second time i have come and found nothing wrong but customer has experienced a shutdown pretty quickly after call for electricity and startup. Giving an alarm "underspeed".
Tested fuel pressure, hertz and stepper motor. Cycled on/off several times while monitoring fuel pressure/hertz and sound. All good.checked connector for stepper and visionally saw it function. Also confirmed no real loads where present at time of alarm. I loaded it and tested all good. This doesnt happen when i am here and during maintenance cycle. There has been a code for check battery at each maintenance cycle.
I appreciate any help.
Tony
I would make sure all the battery connections are good and not corroded (since you're getting the battery alarms), and make sure that the unit is running normal speed during exercise, and not low speed (quiet test).
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
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nickysmith
- New Member
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- Joined: Sat Dec 24, 2022 1:43 pm
Generac 17Kw ran run hours then got the under speed error. I turned off everything in the house that might be drawing power. Same issue. I even turned off the main feed from the generator to the house and it still has the same under power problem. Any suggestions?
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grsthegreat
- Generator Jedi Master
- Posts: 3635
- Joined: Mon Apr 20, 2020 5:59 pm
1603 is fuel supply usually. May have a frozen fuel regulator, or if propane you may be running out of propane below 20% or running on a small tank thats freezing up.
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Goodwin3973
- New Member
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- Joined: Sat Jul 18, 2020 1:54 pm
Chris was a great help on this issue for me. I found that the fuel regulator was malfunctioning . The diaphragm had a hole in it. Replaced it and it runs great. If you see any more than a couple inches of water column drop during startup or load up it could be your problem.
17kw propane generac
Tony
17kw propane generac
Tony