How To Fix Fault Code 1446 On Cummins Generator (Error Solved!)


Have you ever wondered how to fix a fault code 1446 on Cummins generator? Look no more. We´ve got you covered.

Just like any other fault code that initiates an emergency shutdown of the generator, error code 1446 is something that raises an alarm.

Cummins generators have many mechanisms that serve the function of protecting them from damages caused by malfunctions. The fault code 1446 is one of these.

So, how to fix fault code 1446 on Cummins generator? To solve the fault code 1446 on Cummins generator, just check and follow the steps below:

Step #1 Check High AC Voltage threshold

Step #2 Check connections at output terminals

Step #3 Check the engine governor and throttle body

Step #4 Check the AVR circuit

What is Fault Code 1446 on Cummins Generator

The fault code 1446 on Cummins generators happens when the control logic circuits of the PowerCommand control unit detect that the alternating current voltage on one or more phases has been higher than the preset threshold for longer than 10 seconds.

This is a situation that can be very dangerous to any equipment connected to the generator.

While all electrical devices and machines can properly work and it is safe for them to run on the current that is 110% of the nominal rating, voltage above this level can cause damage to it.

This is why, as a safety precaution, the generator will shut down with fault code 1446. The majority of the potential causes of the fault code 1446 are not serviceable by a user.

First and foremost because of the warranty policy of Cummins, and attempting to repair some of these potential causes will void your warranty.

But, non the less, there are some things you could do by yourself, and you should at least be informed what are the issues for which you should get help from an authorized service.

Read also: How To Fix Fault Code 1447 On Cummins Generator

Reading the Fault Code on Cummins Generator

The Cummins generators are known for their PowerCommand control unit which has many very useful functionalities that make operating and maintenance of them very easy and convenient.

Retrieving and reading fault codes that have led to the shutdown of the generator is exceptionally easy with literally a single press of the button.

All you have to do is press the STOP button.

Once you do it, first the shutdown warning light will be lit by a red LED signaling that there was some condition that caused an automatic shutdown.

After this, the LCD of the PowerCommand unit will display the text stating which specific fault code has initiated the emergency stop of the generator.

In this situation that text will say:

  • Fault Number 1446: HIGH AC VOLTAGE

In case that you see this exact text, it is the fault code 1446 you need to take care of.

But, if you are seeing some different, it is a different fault code you have on your hands.

While in such a situation this post will not be very helpful for your situation, you should be able to find an appropriate solution for your particular fault code on other pages of our blog.

Read also: How To Fix Fault Code 359 On Cummins Generator

Troubleshooting fault code 1446

When the fault code 1446 happens to your generator it means that the current on one or more phases went above the High AC Voltage threshold for longer than 10 seconds.

By default, this threshold is 110% of the nominal voltage of the generator, but this can be one of the potential causes of the fault code.

That’s the very first thing you should check for, whether the HighAC Voltage threshold is set below the default value.

Step #1 Check High AC Voltage threshold: High AC Voltage threshold setting is located in the Voltage menu of the Setup Genset section.

While as a user you will be able to read this setting, changing it is protected by the service password and you will not be able to change it.

The default value is 110%, but if you see some lower value that is a potential problem.

All electrical devices and machines tolerate the range between 15% below and 10% above the nominal rated voltages, and having overvoltage protection of the generator above this 10% threshold is not needed.

Because of the way generators are producing electricity, depending on the load the voltage can fluctuate, and it is normal.

Improperly set threshold for overvoltage protection can lead to unnecessary shutdowns and downtime.

Step #2 Check connections at output terminals: In case that this was your first attempt at starting the generator after its installation or some major repair, this fault code could be caused by improper wiring at the generator’s output terminals.

You should consult the installation manual, or authorized service for the exact wiring scheme of these leads, but fixing it shouldn’t take more than a few minutes.

Step #3 Check the engine governor and throttle body: If the generator is often working under the variable loads, eventually it can cause to development f certain issues with the function of the governor and throttle body.

You should check the linkage and whether it functions properly and without any biding, especially the throttle valve which could get stuck open.

This will lead to the generator producing either AC electricity of too high frequency or too high voltage.

If there are any biding in the throttle body or governor, it should be fixed.

Step #4 Check the AVR circuit: Another potential problem that you would not be able to fix by yourself, but you can diagnose is the improper function of the Automatic Voltage Control circuit on the PCC board.

By opening the service panel on which PowerCommand controls are mounted, you can access the J17 connector on the PCC board.

With a voltmeter, then you can measure the output on the J17-1 and J17-2 pins, which should read between 3 and 30 volts DC current when the generator is in the No Load mode.

If the measured currents are above 30 volts, the PCC board, or more precisely the AVR on it is faulty and the whole PCC board needs to be replaced.

Causes of the Fault Code 1446 You Can’t Fix

Faulty optional PMG

In case that your generator’s AVR is equipped with an optional Permanent Magnet Generator, there are chances that it is faulty.

Unfortunately, this is an issue that is not serviceable by the user, and furthermore, attempting to diagnose it will void the warranty for your generator.

It is better to leave it for authorized service than to lose the protection the warranty gives you in case of any problems you may have with your generator.

Prevent Fault Code 1446 from Reoccurring

While the majority of the potential causes of the fault code 1446 are completely out f your control and are not possible to be predicted or prevented, there is something you can do to prevent or decrease the chances of it reoccurring.

The binding of the throttle body of the generator’s engine and in the governor and its actuator are potential causes. Development of these problems can be avoided with some preventative care of your backup generator.

What you can do to prevent this is to prevent the accumulation of dust on the throttle body and governor.

To do this, you need to regularly exercise the generator per the user manual for your specific model.

Generally, this means running it in the No Load mode for a couple of hours every month, and that way you will make sure that your generator is in the best shape fr whenever you need it.

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Mike Gilmour

Hi, I'm Mike, co-founder, and editor of RV and Playa. My passion is traveling (with my RV) and enjoying the day at the beach (Playa)! Well, I originally created this blog as a way to share what I've learned by experimenting with the RV lifestyle, and I want to help others develop in life through new skills and opportunities.

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