How To Fix Fault Code 1435 On Cummins Generator (Error Solved!)


Have you ever wondered how to fix a fault code 1435 on Cummins generator? Look no more. We´ve got you covered.

While almost all error codes on Cummins generator sets will cause a shutdown, there are still several fault codes that serve as warnings of some conditions under which your backup generator is running.

One such fault code is fault code 1435, which can be very alarming when it happens to someone who doesn’t have a lot of experience with operating Cummins generators.

There are few situations in which this warning can show up, and all of them can be resolved very easily and without much of a hustle.

So, how to fix fault code 1435 on Cummins generator? To solve the fault code 1435 on Cummins generator, just check and follow the steps below:

Step #1 Check for coolant leaks

Step #2 Check the coolant level

Step #3 Check coolant heater’s operation

Step #4 Check the low coolant temperature threshold

What is Fault Code 1435 on Cummins Generator

Being able to rely on the backup power generator to take over supplying the electricity when it is needed is always of the utmost importance.

When it is showing the fault code 1435 it means that you will not be able to put the load on it right at the same time when it starts, which is very important especially if you are using it in the automatic mode.

If you do not have much experience with Cummins generators, this fault code might confuse you, especially because you will notice that the generator is still running.

This fault code warning appears when the coolant temperature sensor senses that it is at a temperature below the set threshold.

Such a condition is not a reason for concern, as it can be a normal occurrence in a cold climate, and the only thing it will cause is to delay the moment when the generator can be put under load by some 10 seconds.

Read also: How To Fix Fault Code 1446 On Cummins Generator

Reading the Fault Code on Cummins Generator

While there is a proper procedure for reading all of the fault codes that can initiate a shutdown of the power generator set, when it comes to this particular fault code, it is not the case.

When it happens the LCD screen will read the message:

  • Fault Number 1435: LOW COOLANT TEMP (WARNING)

There are no actions that you will need to take to bring it up on the screen or clear it.

If the default settings of the low coolant temperature alarm are not changed, it will clear by itself in one minute after showing up.

In some cases, besides this fault code, you may notice another one showing up on the LCD screen, in which case you will also have to deal with it.

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

Troubleshooting fault code 1435

The fault code 1435 warning means that the coolant temperature is below the set threshold, so the generator will not be able to accept the load for at least 10 seconds after the start.

The default setting for this threshold is 70 degrees Fahrenheit, and this warning can signal one of four possible problems.

Either the low coolant temperature threshold was changed to some higher setting, the coolant heater is not operating properly, the coolant level is low, or the environmental temperature is below 40 degrees.

In case that the temperature is below 40 degrees, even if the coolant heater is working properly and the coolant level is fine, you will get this warning.

In case that the default settings were not changed, this warning will clear by itself after one minute of the running time of the generator.

While it may raise a concern, this warning only means that the generator will be able to take on the load with some delay, while it will continue running as this fault code does not cause a shutdown.

In such a situation there is not much you can do, but in any case, you should check whether the coolant heater is working properly and that there is enough coolant in the system.

Step #1 Check for coolant leaks: It is a good idea to first check the generator’s inside for the visible signs of the coolant leaks, any sign of coolant pooling in the bottom of the enclosure, or dripping on the inlet or outlet of the radiator.

If you are pouring coolant while it’s leaking somewhere, it is very likely that you will not add a sufficient amount into the system.

If there is any leak, it has to be fixed.

Step #2 Check the coolant level: Checking the level of the generator engine’s coolant is as easy as it sounds.

In case that the coolant level is too low, you will need to top it off.

The general recommendation by Cummins, which you should respect, is to use the mixture of half of the demineralized/purified water and half ethylene glycol-based antifreeze.

When handling ethylene glycol, you should be careful to not spill it on yourself as it can cause irritation.

Step #3 Check coolant heater’s operation: Coolant heaters are an optional part of the low ambient temperature operation equipment for their generator sets.

In case that you have them, you should make sure that they are functioning properly.

First, you need to check whether the heater’s power cable is secured to the heater and secure and tighten its nut if it is needed.

After this, you need to check whether the other end of the cable is properly placed in a socket and whether that socket is live, i.e. it can supply power to the heater.

If all of this were not the problem, the heater is faulty most likely, but you can also measure the temperature of the coolant and if it is lower than the heater’s thermostat setting, the heater is dead and needs to be replaced.

If none of the above is the cause of the low coolant temperature warning, the only other option is that the threshold is set lower than the default value.

While it is not recommended to change any of the advanced settings of your Cummins generator by yourself, nothing stops you from actually checking this setting.

Step #4 Check the low coolant temperature threshold: By pressing the Home button on the PowerCommand control unit you will open the HOME menu, here using the up and down arrow keys you should navigate to the Genset Setup item and press the OK button.

By using the soft key under the right lower corner of the screen, you can navigate to the 4th page of the Genset Setup section, where you can read in the Low Coolant Temp Warning section what is the setting for Threshold, Set Time and Clear Time.

Read also: How To Fix Fault Code 427 On Cummins Generator

Prevent Fault Code 1435 from Reoccurring

Though there are four possible causes of this fault code, there is not much that you can do to prevent them.

In case that you have an engine coolant heater installed, just like any other part, they are bound to fail at some point in time.

The likelihood of this happening is very low, but once it does happen, you can decrease it only by using the official replacement parts and services of certified Cummins repair technicians.

The other thing which you could do, and could decrease the chances of the fault 1435 showing up is proper regular maintenance.

Because the low coolant level can trigger this fault code, you should make sure to check the coolant level at the appropriately suggested rhythm, every 24 hours of running time.

And also to check from time to time hoses and connectors of the engine’s cooling system for signs of any leak developing and fixing it as soon as possible.

Here are some of my favorite services, products, and Stores

Thank you for reading this article. I hope it helps you find the most recent and accurate RV, camping information. Here are some services, products, and Stores that I use and hope you´ll also find helpful.

There are affiliate links, so if you do decide to use any of them, I´ll earn a small commission. But in all honesty, these are the exact what I use and recommend to everyone, even my own family.

To see all my of most up-to-date recommendations, check out this resource that I made for you!


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.

Recent Posts

error: Content is protected !!