Regeneration Overview: How to Respond at Each Stage

You’re halfway through a big project and—boom!—one of your regeneration indicator lights pops on. What should you do next? 

Here, we provide an overview of regeneration: what it is, how it works, and how to respond when that first light comes on (and what happens if you don’t!). 

What is Regeneration? 

Today’s tractors run cleaner than ever before. This is due to an increase in EPA emission standards that every manufacturer must adhere to. Yanmar continues to exceed these standards thanks to our excellent engine and diesel particulate filter (DPF) design. 

Regeneration is the self-cleaning process that your engine performs when soot particulates from your exhaust build up in the DPF. Our tractors are engineered to conduct continuous self-regeneration, ensuring optimal efficiency and minimizing the release of harmful emissions. However, if proper steps are not taken immediately when regeneration notifications pop up on your tractor panel, there can be severe consequences to your tractor’s performance that result in a trip to your local dealer

Here’s how to avoid that trip. 

The Five Levels of Regeneration 

To maintain the DPF in accordance with emission standards, five levels of regeneration have been built into the operation of your Yanmar tractor.  

1. Self Re-Gen

Yanmar tractors are designed to self-regenerate whenever they are in operation. Under normal working conditions, heat is captured from the exhaust while you operate the tractor. The harder the tractor works, the higher exhaust temperatures will rise. Heat from the exhaust is captured and used to efficiently burn soot particulates in the DPF. This process is automatic, nearly undetectable by an operator, and occurs without intervention. 

2. Assist 

If soot accumulates beyond what the self-regen can process, assist regeneration will automatically occur. While the tractor operates, the electronic controller on the engine will partially close the intake throttle. This raises the heat levels in the exhaust. These higher temperatures can burn more soot. 

Assist regeneration won’t require you to stop working, and will likely go unnoticed. The only indication that an assist regeneration is occurring may be a slight sound change or different exhaust smell. Simply continue operating your tractor normally. 

3. Reset 

The next level of regeneration is called reset. This is the first time the operator will see a regeneration indicator light on the tractor panel, and the first time a regen process will require operator intervention. 

Reset regeneration is baked into your tractor’s periodic maintenance schedule. Expect to see a reset regeneration indicator light after your first 50 hours of operation and then every 100 hours. Reset will also occur if assist regeneration is unable to effectively lower your soot levels. At this time, you will want to perform a manual reset regeneration (see part two of this series for instructions on how to perform a reset regeneration). 

Tractors that are well maintained, and experience no equipment failures, will not go past the reset regeneration step.

4. Stationary

If soot levels continue to rise, or the request to perform a reset regeneration is ignored, your tractor will make a stationary (also sometimes called “park”) regeneration request. This request will be accompanied by a caution lamp indicator light, audible alarm, and a diagnostic trouble code on your tractor panel.

If these indicators are ignored, the tractor will experience a gradual power reduction and advance to the recovery regeneration stage. You don’t want to hit that stage, so take steps now to perform a stationary regeneration. 

The tractor must be parked during this regeneration phase. To resolve this request, you will want to perform a stationary regeneration (see part three of this series for instructions on how to perform a stationary regeneration). 

5. Recovery

If a stationary regeneration is not performed and soot levels continue to surge, a recovery generation will be required. This is a severe state. The tractor’s operation will be restricted to slightly above idle until the stationary regeneration maintenance is performed. 

Unfortunately, recovery regeneration requires the use of a diagnostic tool to perform. That means that recovery generation must be completed at the dealer. 

How to Avoid Recovery Regeneration 

Regeneration strategies become more aggressive as soot accumulates. That’s why it’s so important to take care of the issue immediately when you see the first regeneration notification. Other ways to prevent unnecessary regeneration include working the tractor harder at high engine speeds (to efficiently burn the soot) while avoiding unnecessary idling. 

Also make sure to use the proper fuel and oil. A biodiesel blend of seven percent or less is ideal. Yanmar tractors may operate on blends of up to twenty percent, with special precautions. Refer to your manual for these precautions. Yanmar tractors should never be operated with biodiesel blends of greater than twenty percent.

Connect With Yanmar

Whether you’re new to the world of tractors or have owned a Yanmar for years, our dedicated Customer Experience Team is here to help. From questions about regeneration to ongoing maintenance tips, don’t hesitate to connect with us online or give us a call at 678-551-7369.

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