Onan Microquiet 4000 Troubleshooting

If you blink you may miss it. That may be a bad pun, but it is the truth when it comes to Onan generators. When something goes wrong, the generator will send out a code to tell you the problem. If you blink, you may miss the number of the error code.

How to Read Onan Generator Fault Codes: It's not hard to read the Onan Fault Code blink system, once you get used to it. They use a blink and pause design to make their numbered codes clear and not confusing. For example, if the light blinks 5 times then pauses, then blinks 1 more time, that signifies Fault Code 51.

Re: Onan Microquiet 4000 problems « Reply #4 on: June 26, 2011, 01:35:15 PM » In this case, from his description, he was using an ordinary house extension cord and not the normal 30 amp cord.

(available from Cummins Onan) is bolted or a collar to which the tailpipe is clamped or a short adapter bolted.View and Download Onan MicroLite Series service manual online. MicroLite Series Portable Generator pdf manual download. Introduction This is the service manual for the KY Series MicroLite generator sets (gensets). Onan RV Generator Troubleshooting. The first step in fixing Onan RV generators is troubleshooting. Here are some of the things you can check on your own. Make sure to try these things before paying a professional, as this could save you quite a bit of money. Begin by checking the fuel level.

To learn more about the different Onan Fault Codes, what they mean and how to fix the problem, just keep reading our article. All the information is here for you to learn from. Onan Fault Codes are easy to learn if you do not blink while they are sending their message.

Onan Generator Fault Code List

Code 2 - Low Oil Pressure

This code will only blink twice. It shows that the generator is low on oil and you need to add more. Twist off the yellow cap to look at the gauge and see how much more you need to put in.

Just remember to not over-fill your oil tank. Too much oil is not a good thing

Code 3 - Service Check

When you see this code, it indicates that there is a problem somewhere on your Onan generator. You will get 3 flashes then a pause, then 3 flashes, then a pause and on it goes till you press the button to get the secondary code.

The secondary code will give you the specific problem that is wrong with your generator

Code 4 - Over Crank

The first thing you need to do when you see this code is to try to reset your control board. You do this by turning the switch off and then hit the reset button. Next, you need to turn the switch back to run. If it starts you are fine. If it doesn't and the code returns, then you need a new control board

Code 12 - Over Voltage

This problem comes from a faulty inverter and that part is overcharging the generator. The only way to solve this Fault Code problem is to take the generator to a qualified Onan dealer or repair shop.

Alternative sources for this code may be a lack of fuel or a clogged filter problem. Then you just add more fuel or replace/clean the filter

Code 13 - Under Voltage

This code tells you that the controller is incapable of maintaining proper voltage levels. There is a simple fix to this problem. Unplug all unneeded appliances while the air conditioner and battery charger are running.

Another source for this problem would be that the engine slowed down for a variety of reasons like a lack of fuel.

Onan Microquiet 4000 Troubleshooting Solenoid

Code 14 - Over Frequency

This code tells you that the engine is running too fast and the sources for this code could be one of the following reasons: air leak at the intake, carb, and linkages not properly installed, misadjusted governor, broken governor.

Check your frequency levels first. Then clean or replace your carb, check to make sure the linkage is not reversed or replace the governor. For more info, read our Onan generator fault code 14 guide.

Code 15 - Under Frequency

This is the opposite of the above code. When you see this number, your engine is running too slow. The solution may be that everything was not connected properly or that the governor is in the wrong spot. It has to be in the 5^thnotch from the right.

If the generator still flashes, you may have restarted your generator in under a minute and are running in ERO mode. You get the engine running but no power in this mode. Turn the generator off and wait for at least 2 minutes before restarting.

Code 19 - Governor Actuator Overload

The governor has one wire to the controller and one wire for ground. If either one is loose, that will trigger this code. All you have to do is tighten the loose wire and you should be good to go.

If that doesn't work or the wires are tight, the manual states that you are to go to a certified Onan repairman and get the problem looked at.

Code 23 - Low Oil Pressure Cutoff Switch

This code would indicate a problem with the cutoff switch itself. There is a malfunction in the switch and you probably won't be able to fix it yourself.

The manual states that you need to go to the nearest certified Onan dealer to get the problem solved for you. There will be a lot of these type of solutions throughout this code explanation

Code 27 - Voltage Sense Error

What this fault code tells you is that the controller cannot sense the output voltage. Again, this problem may be beyond your expertise to repair. The manual states that the only solution is to go to your authorized Onan dealer to rectify the issue.

Code 29 - High Battery Voltage

This is the simple way to say that the voltage across your battery system is more than 19 volts. What you need to do is check your battery bank connections and if necessary, reconnect them in the proper order.

12-volt connections need to be parallel and 24-volt connections are done n a series. Another solution would be to set a lower battery boost charge rate

Code 31 – Overspeed

3 flashes, a pause and then one flash tells you that your Onan generator is going faster than 3,400 rpm. The trick here is to make sure you do not confuse 13 with 31. You can double-check by pressing the stop button 3 times in 5 seconds.

Once you return to the initial 3 flashes press the stop button again to get the secondary code to double-check your first reading. When you confirm the 31 code, you need to take the generator to the certified Onan dealer to get it fixed

Code 32 - Low Cranking Speed

This code informs you that your cranking speed is below 180 rpms for 2 seconds. To solve this problem, you need to clean the battery connections, or recharge/replace the batteries or replace the engine oil with the proper viscosity

Code 35 - Control Card Failure

During a self-test you may see this code pop up. The generator is telling itself that there is an error in the microprocessor EEPROM. You won't be able to fix this issue and need to take it to the certified Onan dealer near you.

Code 36 - Engine Stopped

That is without command by you. You could be out of fuel or you have a low LPG pressure issue, or your spark plug leads may be loose, or you have bad spark plugs. Finally, you may have to clean or replace the air cleaner or check for some other mechanical failure.

Code 37 - Invalid Generator Set Configuration

This simple message simply says that your Onan generator is set at the wrong frequency. To correct this issue, you should see your certified Onan dealer. They have the right tools to handle this problem

Code 38 - Over Current (Field Overload)

Or in simple English, you have too many appliances running at the same time. Also, you should check your air conditioner and other appliances to make sure there is not a problem with them.

Code 41 - Generator Rotor

Your controller is not sensing either field or output voltage. This is probably another issue you will not be able to fix yourself and the manual says for you to take your generator to an authorized Onan dealer for repairs.

Code 42 – Processor

This number tells you that your Onan generator detected an error within its Microprocessor Rom section. Again, you should not tackle this problem yourself but take your generator to your nearest certified Onan dealer.

Code 43- Processor Fault Code.

There is a problem with the Microprocessor RAM and see above to find the fix.

Code 45 - Speed Sense

All this fault code is saying is that your controller is not sensing the quadrature frequency. The simple fix for this issue is for you to bring your generator into the certified Onan dealer's shop and let them fix it for you.

Code 47 – Ignition

Once again the issue lies with the controller. It is not in bad shape, but it cannot sense any ignition when you try to start your generator. This also is an issue for your certified Onan dealer to handle.

Code 48 - Generator Field Sense

Once again, the controller is unable to sense a vital part of your generator's operating system. This time it is the field voltage that escapes its attention. See your authorized Onan dealer to fix this problem.

Code 51 – Processor

This is another key code telling you that there is a problem with the installed microprocessor. You will need to see your qualified Onan dealer to get this taken care of.

Code 52 - Fuel Injector

Here you have an open or short circuit in your fuel injector. This is another problem the manual says you need to take to your Onan dealer to get it taken care of.

Code 54 - MAT Sender

The MAT sender has an open or short circuit in it and it may be beyond your abilities to fix yourself. The manual states to bring your generator to your trusty Onan dealer to fix.

Code 56 - MAP Sender

This is not the same as the MAT. But the problem is the same with an open or short circuit in your MAP sender. The solution is the same as your Mat solution.

Code 57 - Over Prime

When your prime mode goes past 3 minutes, then this error code will appear. Check for and then remove any object that may be keeping the control switch in the prime position

Code 58 - Exhaust Gas Temperature Shutdown

What causes this error code is a lean fuel supply, restricted exhaust system, bad ignition system, bad heat sensor, and other issues. To keep your warranty valid, you need to take your generator to your Onan dealer for diagnosis and repair.

Code 81 - Exhaust Gas Temperature Sensor Open

This may mean that your temperature sensor is stuck open and will not close. It is best if you take your generator to your local Onan dealer to have them repair the problem

Code 82 - Exhaust Gas Temperature Shorted

You have a possible short circuit and it is a problem you should not deal with yourself. Your local authorized Onan dealer has the tools and expertise to fix this issue for you

Onan Generator Code Reset

Resetting your Onan Generator is not that difficult. All you have to do is follow these simple steps and you should be fine:

• Locate the primer button. This doubles as the start and stop button on your generator
• Hold the button down for about 30 seconds- Release the button and then start your generator
• Run the generator for 15 minutes to see if the code has been cleared. If not, then you may need the help of a qualified nan repairman to fix the problem

Some Final Words

Technology does bring a lot of wonderful toys to your life. It also helps make your life a little simpler. But the one drawback to new technology is that there is always some new problem that can arise.

That is why learning and understanding fault codes is so important. Once you learn and understand them you know what you have to do to solve the problem That knowledge also makes life a little simpler to live

Don't be afraid of technology, learn how to use it and learn the fault codes so you know what needs to be done next before you cause more problems that may raise your repair costs.

Onan Generator Troubleshooting; 13 Tips for RV Generator Repair

Onan Microquiet 4000 Troubleshooting Solenoid

Onan is known for its standby generators. However, they also make portable generators, especially those that go in RVs. Many Onan generator models can run on gasoline and liquid propane. Their generators are typically compact and relatively quiet. They often sell generators in portable shells that protect them while muffling the sounds it makes.

Their generators regularly come with intelligent control boards capable of self-diagnostics, while most units have an integrated design that is incredibly easy to connect to your RV. That is aside from the fact that Onan generators are often built into the RV by the manufacturer.

Here are our top 13 tips for getting the most of out your Onan generator troubleshooting fixed.

Onan is one of the top selling generator brands in the United States. However, the brand has been picked up by Cummins. That's why you now see products listed as Cummins Onan or Cummins part number Onan.

This means that you may have to search for the Onan part number in the Cummins inventory listed on a website. That's especially true for consumable parts like spark plugs and air filters.

For example, the Onan generator manufacturer's home page is now www.cumminsonan.com.

If your Onan generator isn't running, it may be because fuel levels are too low. While some RV generators will run until the fuel tank has nothing but fumes, the Onan models tend to stop working when you're down to a quarter tank. The units that do this are the ones drawing from the gas tank.

The intent is to ensure that the RV isn't stranded because you have no gas in the tank. In the future, top off your RV gas tank so that it never runs low. And know that the generator will shut down if the gas gauge is around one quarter.

Note that you can really run into problems if the gas tank float is off, so the generator turns off though you have a half-full tank.

Check your frequency levels first. Then clean or replace your carb, check to make sure the linkage is not reversed or replace the governor. For more info, read our Onan generator fault code 14 guide.

Code 15 - Under Frequency

This is the opposite of the above code. When you see this number, your engine is running too slow. The solution may be that everything was not connected properly or that the governor is in the wrong spot. It has to be in the 5^thnotch from the right.

If the generator still flashes, you may have restarted your generator in under a minute and are running in ERO mode. You get the engine running but no power in this mode. Turn the generator off and wait for at least 2 minutes before restarting.

Code 19 - Governor Actuator Overload

The governor has one wire to the controller and one wire for ground. If either one is loose, that will trigger this code. All you have to do is tighten the loose wire and you should be good to go.

If that doesn't work or the wires are tight, the manual states that you are to go to a certified Onan repairman and get the problem looked at.

Code 23 - Low Oil Pressure Cutoff Switch

This code would indicate a problem with the cutoff switch itself. There is a malfunction in the switch and you probably won't be able to fix it yourself.

The manual states that you need to go to the nearest certified Onan dealer to get the problem solved for you. There will be a lot of these type of solutions throughout this code explanation

Code 27 - Voltage Sense Error

What this fault code tells you is that the controller cannot sense the output voltage. Again, this problem may be beyond your expertise to repair. The manual states that the only solution is to go to your authorized Onan dealer to rectify the issue.

Code 29 - High Battery Voltage

This is the simple way to say that the voltage across your battery system is more than 19 volts. What you need to do is check your battery bank connections and if necessary, reconnect them in the proper order.

12-volt connections need to be parallel and 24-volt connections are done n a series. Another solution would be to set a lower battery boost charge rate

Code 31 – Overspeed

3 flashes, a pause and then one flash tells you that your Onan generator is going faster than 3,400 rpm. The trick here is to make sure you do not confuse 13 with 31. You can double-check by pressing the stop button 3 times in 5 seconds.

Once you return to the initial 3 flashes press the stop button again to get the secondary code to double-check your first reading. When you confirm the 31 code, you need to take the generator to the certified Onan dealer to get it fixed

Code 32 - Low Cranking Speed

This code informs you that your cranking speed is below 180 rpms for 2 seconds. To solve this problem, you need to clean the battery connections, or recharge/replace the batteries or replace the engine oil with the proper viscosity

Code 35 - Control Card Failure

During a self-test you may see this code pop up. The generator is telling itself that there is an error in the microprocessor EEPROM. You won't be able to fix this issue and need to take it to the certified Onan dealer near you.

Code 36 - Engine Stopped

That is without command by you. You could be out of fuel or you have a low LPG pressure issue, or your spark plug leads may be loose, or you have bad spark plugs. Finally, you may have to clean or replace the air cleaner or check for some other mechanical failure.

Code 37 - Invalid Generator Set Configuration

This simple message simply says that your Onan generator is set at the wrong frequency. To correct this issue, you should see your certified Onan dealer. They have the right tools to handle this problem

Code 38 - Over Current (Field Overload)

Or in simple English, you have too many appliances running at the same time. Also, you should check your air conditioner and other appliances to make sure there is not a problem with them.

Code 41 - Generator Rotor

Your controller is not sensing either field or output voltage. This is probably another issue you will not be able to fix yourself and the manual says for you to take your generator to an authorized Onan dealer for repairs.

Code 42 – Processor

This number tells you that your Onan generator detected an error within its Microprocessor Rom section. Again, you should not tackle this problem yourself but take your generator to your nearest certified Onan dealer.

Code 43- Processor Fault Code.

There is a problem with the Microprocessor RAM and see above to find the fix.

Code 45 - Speed Sense

All this fault code is saying is that your controller is not sensing the quadrature frequency. The simple fix for this issue is for you to bring your generator into the certified Onan dealer's shop and let them fix it for you.

Code 47 – Ignition

Once again the issue lies with the controller. It is not in bad shape, but it cannot sense any ignition when you try to start your generator. This also is an issue for your certified Onan dealer to handle.

Code 48 - Generator Field Sense

Once again, the controller is unable to sense a vital part of your generator's operating system. This time it is the field voltage that escapes its attention. See your authorized Onan dealer to fix this problem.

Code 51 – Processor

This is another key code telling you that there is a problem with the installed microprocessor. You will need to see your qualified Onan dealer to get this taken care of.

Code 52 - Fuel Injector

Here you have an open or short circuit in your fuel injector. This is another problem the manual says you need to take to your Onan dealer to get it taken care of.

Code 54 - MAT Sender

The MAT sender has an open or short circuit in it and it may be beyond your abilities to fix yourself. The manual states to bring your generator to your trusty Onan dealer to fix.

Code 56 - MAP Sender

This is not the same as the MAT. But the problem is the same with an open or short circuit in your MAP sender. The solution is the same as your Mat solution.

Code 57 - Over Prime

When your prime mode goes past 3 minutes, then this error code will appear. Check for and then remove any object that may be keeping the control switch in the prime position

Code 58 - Exhaust Gas Temperature Shutdown

What causes this error code is a lean fuel supply, restricted exhaust system, bad ignition system, bad heat sensor, and other issues. To keep your warranty valid, you need to take your generator to your Onan dealer for diagnosis and repair.

Code 81 - Exhaust Gas Temperature Sensor Open

This may mean that your temperature sensor is stuck open and will not close. It is best if you take your generator to your local Onan dealer to have them repair the problem

Code 82 - Exhaust Gas Temperature Shorted

You have a possible short circuit and it is a problem you should not deal with yourself. Your local authorized Onan dealer has the tools and expertise to fix this issue for you

Onan Generator Code Reset

Resetting your Onan Generator is not that difficult. All you have to do is follow these simple steps and you should be fine:

• Locate the primer button. This doubles as the start and stop button on your generator
• Hold the button down for about 30 seconds- Release the button and then start your generator
• Run the generator for 15 minutes to see if the code has been cleared. If not, then you may need the help of a qualified nan repairman to fix the problem

Some Final Words

Technology does bring a lot of wonderful toys to your life. It also helps make your life a little simpler. But the one drawback to new technology is that there is always some new problem that can arise.

That is why learning and understanding fault codes is so important. Once you learn and understand them you know what you have to do to solve the problem That knowledge also makes life a little simpler to live

Don't be afraid of technology, learn how to use it and learn the fault codes so you know what needs to be done next before you cause more problems that may raise your repair costs.

Onan Generator Troubleshooting; 13 Tips for RV Generator Repair

Onan Microquiet 4000 Troubleshooting Solenoid

Onan is known for its standby generators. However, they also make portable generators, especially those that go in RVs. Many Onan generator models can run on gasoline and liquid propane. Their generators are typically compact and relatively quiet. They often sell generators in portable shells that protect them while muffling the sounds it makes.

Their generators regularly come with intelligent control boards capable of self-diagnostics, while most units have an integrated design that is incredibly easy to connect to your RV. That is aside from the fact that Onan generators are often built into the RV by the manufacturer.

Here are our top 13 tips for getting the most of out your Onan generator troubleshooting fixed.

Onan is one of the top selling generator brands in the United States. However, the brand has been picked up by Cummins. That's why you now see products listed as Cummins Onan or Cummins part number Onan.

This means that you may have to search for the Onan part number in the Cummins inventory listed on a website. That's especially true for consumable parts like spark plugs and air filters.

For example, the Onan generator manufacturer's home page is now www.cumminsonan.com.

If your Onan generator isn't running, it may be because fuel levels are too low. While some RV generators will run until the fuel tank has nothing but fumes, the Onan models tend to stop working when you're down to a quarter tank. The units that do this are the ones drawing from the gas tank.

The intent is to ensure that the RV isn't stranded because you have no gas in the tank. In the future, top off your RV gas tank so that it never runs low. And know that the generator will shut down if the gas gauge is around one quarter.

Note that you can really run into problems if the gas tank float is off, so the generator turns off though you have a half-full tank.

Onan generators have a number of built-in safety features. One of these is the fuel cut-off switch so you don't use all your gas running power though it would leave you stranded on the side of the road.

Another is the low oil cut-off. If the generator is cutting off, check the oil levels. You can avoid problems by making sure the oil tank is full. It also means that an oil leak in the generator can kill it well before the unit suffers damage.

If the safety feature trips and the generator is giving you an error code, look it up before assuming that resetting the generator is all you need to do. For example, issues that make a generator run rough could be deal with temporarily, but the long-term damage will destroy the generator.

Onan generators are among the smartest on the market. They can self-diagnose issues. However, it won't tell you outright it thinks the oil is low. Instead, it flashes codes to indicate the problem.

One solution is to check the manual. What if you don't have the manual? Then you can go to www.cumminsonan.com and look up the error codes. Even the error codes for older and rare Onan generators can be looked up on that site.

Onan Microquiet 4000 Troubleshooting Codes

Onan has made a number of design changes that simplify maintenance. For example, the Onan 4K generator doesn't have an oil filter. On the other hand, you have to use the right oil and never use old oil to keep the generator from clogging up.

Know the right level of oil, because over-filling will cause the generator to shut off just as too much would. Know where you would access the carburetor if you need to clean it and where you access other points required for maintenance.

In some cases, you have to restart the line breaker in the RV to get the power going after you've done maintenance on the generator. This is because of the safety features built into the RV after you've lost power, even if it was because you disconnected the battery while working on the generator.

Always know where the circuit breakers and other electrical panels are so that you can reset or repair things as necessary.

Do you have a dual fuel generator in your RV? For example, some Onan generators can run off both gasoline and liquid propane. This allows you to conserve gasoline when you're away from civilization.

And it allows you to switch to another fuel source to see if the root cause of it shutting down is a low gas level. For example, switch to propane if the gas tank is getting low. And consider carrying extra propane tanks in addition to gas cans.

Do you need extra air conditioning in your RV to stay comfortable? Onan generators don't have the same peak load / surge capacity as some inverter generators. This means you should turn on the RV generator before you turn on the roof-top AC to avoid tripping electrical safeties.

And don't try to turn on too many things at once, since that can cause surges that trip the safety measures like the over-voltage protection.

Onan Generators For Rvs Manual

Onan generators are often powerful. For example, you can find units that can power one or two air conditioners. However, they don't always have excess capacity. Know how much power the generator can supply and the load everything you're running in the RV will draw.

For example, you may be able to run the air conditioner at full blast and the refrigerator at the same time but not the microwave, too.

Onan Microquiet 4000 Parts Catalog

The 7000 watt Onan RV generators may seem like they can run everything in the RV, but you can cause it to trip safeties if you try to do too much. The over voltage protections in particular tend to engage when you walk into the RV and turn everything on.

Onan itself is known for high quality generators. Onan is relying on network of contracted dealers to provide service for most of their RV generators. Service levels vary between mechanics and RV shops.

Do your research before you bring in your RV for service. And verify that the RV shop is experienced working with Onan Cummins generators. Just because they can work with other brands doesn't mean they know how to repair Onan Cummins generators.

While the Onan RV generators are an industry standard, not all service providers can and will have replacement parts in stock.

In most cases, your Onan generator is USDA Forest Service Approved. Do you know what that means? Why yes, Mr. Forest Ranger, we are allowed to run the generator in our RV while we're parked in sensitive national parks, because we know it can't accidentally spark a wildfire.

Nearly all Onan generators also meet the National Park Service sound level requirement. That is 60 decibels of noise or less at a distance of fifty feet. These rules may allow you to run your generator later at night in RV parks with noise limits, too, but you should know their rules rather than assuming you're already compliant.

Onan warranties depend on the application. For example, it is common to see a three year or 2000 hour warranty on an Onan generator. If you're running it nearly all day every day, that means you've blown through the warranty in a year.

Another issue is the application. The Onan generator's three year limited warranty is when it is in the RV and only powering the RV. If you take it out of the RV and use it to provide backup power for your home, the warranty is two years at most.

If you put an RV generator in your shed and use it as a backup power source, it will then have the two year non-RV warranty in place if it applies at all. Find out what the warranty will be from the supplier.

We already mentioned that Onan generators sometimes don't have oil filters. They generally have fuel filters. However, those are not always easy to replace and can be expensive. This makes using quality consumables.

Don't put old gas or watery gas in your generator. Only use high quality gas, though this doesn't mean you have to use premium gasoline.

This also means you'll get extra mileage out of the generator if you use a good fuel injector cleaner periodically. While that adds to the cost of your maintenance routine, it is a necessity because Onan generators are designed to run smoothly on high quality intakes.

If you did use cheap gas or the wrong fuel, clean everything immediately to avoid problems.

The odds are high that your RV generator is an Onan Cummins or original Onan model. Know how to sustain, maintain and repair common issues with the generator to minimize trips to the mechanic and maximize the running life of the most important equipment in the RV aside from the car motor.