When a Check Engine Light Threatens the Flow of a $4 Billion Construction Project

That was the case when PCL Construction contacted us about a Capacity yard truck working at the Bison Generation Station near Ray, North Dakota.

The Bison Generation Station is a nearly $4 billion power generation project being built by PCL Construction for Basin Electric Power Cooperative. The project is designed to provide up to 1,490 megawatts of generating capacity when complete.

With a project of that size, keeping equipment moving is critical.

And this Capacity truck was moving constantly.

Moving Materials From Staging to the Active Site

The Capacity yard truck was being used to move materials from a staging location to the active construction site.

It wasn't an occasional-use piece of equipment. It was working throughout the day, helping keep materials moving where they needed to go.

Then the check engine light came on.

On a project of this scale, a problem like that can't simply be ignored. The truck needs to keep working, but operating equipment with an unresolved engine or emissions fault can create bigger problems if the issue isn't diagnosed correctly.

PCL needed someone to come to the site, figure out what was happening and get the truck back to work.

That's where we came in.

Diagnosing the Problem On Site

We went directly to the Bison Generation Station and started with diagnostics.

Instead of guessing at the problem or immediately replacing parts, we connected to the truck and worked through the diagnostic information.

The truck was showing SCR efficiency fault codes.

SCR, or Selective Catalytic Reduction, is part of the emissions system on modern diesel equipment. The system uses Diesel Exhaust Fluid, or DEF, to reduce NOx emissions in the exhaust.

When an SCR efficiency fault appears, there can be several possible causes. The important part is determining what is actually causing the fault before replacing expensive components.

We continued troubleshooting the system and inspected the DEF injection side.

Finding the Problem

We pulled the DEF injector and found buildup that needed to be cleaned.

One of the reasons we believe that buildup occurred is the way the truck is used.

The Capacity spends much of its day working around the construction site, moving materials between the staging area and the active site. That means it can spend significant amounts of time idling or operating at low speed.

That type of duty cycle can contribute to buildup in emissions-system components, including around the DEF injector.

We cleaned the injector, reassembled the system and then performed an SCR test to verify that the system was functioning properly.

The test came back good.

The truck was ready to get back to work.

Diagnostics Before Parts

Modern diesel emissions systems can generate complicated fault codes, and an SCR efficiency code doesn't automatically mean that an expensive emissions component has failed.

That's why proper diagnostics matter.

In this case, we didn't simply start replacing SCR components. We followed the diagnostic information, inspected the system, found the buildup at the DEF injector, cleaned it and then verified the repair with an SCR test.

The successful test gave us confidence that the system was operating properly before putting the truck back into service.

That's the difference between diagnosing a problem and simply replacing parts until the light goes away.

Keeping Construction Moving

On a project like the Bison Generation Station, every piece of equipment has a job.

The Capacity yard truck's job was moving materials from the staging area to the active construction site. When that truck has a problem, it can affect the flow of materials and the people and equipment depending on those materials.

Being able to respond directly to the job site meant we could diagnose the problem where the truck was working, make the repair and get it back into service without unnecessary transportation or downtime.

At Mondak Equipment and Hose, we provide mobile equipment diagnostics and repair throughout the Williston Basin and surrounding areas.

When equipment goes down, our goal:

Diagnose it. Repair it. Get back to work.