Hardin County School District

Customer Spotlight Hardin County School District

Expert diagnostics take the mystery out of engine fault codes.

Imagine being on route, miles from help, with a school bus full of students, and not knowing why a dashboard light activates. Now imagine your bus is put out-of-service and you get to wait (with your students) for a mechanic or a backup bus.

For Hardin County Schools (HCS) drivers, this was reality.

HCS covers 528 square miles and is located about 50 miles south of Louisville, Kentucky. Each day, district bus drivers transport 12,000 K-12 students, plus 2,000 early college and technical center students. The fleet uses nearly 185 buses and covers more than 18,000 rural and urban miles.

When a bus threw a fault code while on route, not knowing the details or severity had a ripple effect that wasted resources and impacted uptime.

Diagnosis: Lack of insight.

Transportation Director Chris Corder oversees HCS’s fleet operations. In 2020, he decided they needed a reliable solution for diagnosing engine problems. He found that the Zonar and Cummins partnership enables near-instant fault code diagnosis, including severity. And provides expert recommended action plans.

Now, HCS drivers and mechanics finally:

  • know what’s going on under the hood
  • determine the problem’s actual severity
  • respond based on data and expert insight

They saved three bus engines in the first six months.

Guesswork didn’t work.

Before having detailed Cummins diagnostic insights, drivers and mechanics relied on each bus’s internal fault code systems. The information these systems provided was unclear and incomplete. And the buses’ legacy dashboard lights were too vague to determine much about the specific fault.

As Corder put it, “It was all a guessing game as to what might be wrong.”

  • A fault code might suggest a serious problem and put the bus out-of-service (OOS).
  • Reaching OOS buses in remote locations took up to an hour.
  • Time and resources were wasted fixing what turned out to be minor problems.
  • Unnecessary trips to OOS buses took mechanics away from other priorities.

And vice versa. A fault code would appear minor, yet a critical problem would be developing that even experienced mechanics could miss.

When a fault code was specific, drivers and mechanics had to work together to identify the cause with incomplete information. And drivers still had to guide mechanics to their location.

Solution: Expert diagnostics and analysis.

Our partnership with Cummins pairs Zonar precision telematics technology with Cummins advanced diagnostic capabilities. Fleets keep Cummins engines healthy and prevent progressive engine failure.

The Zonar V4 TCU taps into the Cummins engine control module (ECM) to gather a continual stream of detailed data. Cummins Connected Diagnostics uses that data to wirelessly, continually monitor and diagnose system fault alerts, including for school buses deployed on route.

This unique analysis:

  • prioritizes fault codes
  • determines their probable cause
  • reports all of this information to fleet management

Cummins delivers immediate diagnosis of an engine system fault alert. And our telematics data show how each bus is performing for more insight into vehicle and fleet health.

Saved 3 engines in first 6 months.

With Cummins diagnostics and expert analysis, HSC can access the relevant data in seconds, to make the right call, faster. And respond to faults instantly.

“The garage absolutely loves it. We use it every day,” says Corder. “The first six months, we were able to immediately detect problems that would have blown an engine. We saved two or three engines alone during this period.”

Real diagnostics deliver real results.

Condensed, prioritized reports make it easier to recognize and address critical issues in order of importance. Mechanics have the information they need to make data-driven decisions in seconds.

Jobs are completed more efficiently and effectively, which translates into:

  • less wasted time, budget and fleet resources
  • greater vehicle availability and uptime
  • more effective driver and mechanic productivity

OOS buses receive repairs sooner.

With Cummins advanced diagnostics, fewer buses rendered OOS unnecessarily. But if a bus needs immediate repair in the field or a replacement to finish the route, HSC:

  • looks up the real-time Zonar GPS location
  • directs it to a service station or other safe area
  • sends a mechanic directly to its location

“All a mechanic has to do is use the Zonar app on their phones when they have to go on a service call,” describes Corder. “They just pull up the bus and bang, they don’t have to worry about where the bus is and where they need to go.”

Parents’ minds are put at ease.

With more insight into Cummins engine faults, HSC now informs parents when a bus might be late because of a breakdown, and where it’s located. They also let the parents know how the district is handling the issue to provide peace of mind.

Support stays top-notch.

Corder regards Zonar Customer Success as second to none. And he tells us why.

“Zonar support is top-notch, and there’s always somebody available who is very knowledgeable. If there’s a technical issue, somebody can answer it. Not once have I ever had support tell me that they’ll have to check with so-and-so and get back to me.”

His Zonar representative also checks in on a monthly basis, just to see if HSC needs anything.

Between Cummins Connected Diagnostics, our precision GPS tracking and vehicle performance data, plus Zonar customer support, HSC looks forward to working Zonar for the foreseeable future.

When other providers approach him, Corder cuts to the chase. “We’re not looking because we are very happy with what we’ve got.”


Hardin County School District




Hardin County, Kentucky




185 buses

  • 3 engines saved in first 6 months
  • Immediate engine fault code diagnosis & alerts
  • Real-time expert analysis
  • Fewer unnecessary OOS buses
  • More vehicle & driver uptime
  • Less waste of time & resources