The Problem: Finding a Reliable LLY Duramax FICM

For the last year, the engineers at Circuit Board Medics have been hard at work trying to solve a problem that has plagued LLY Duramax owners for years; the fuel injection control module, or FICM for short. This FICM has been one of the most asked for products when we go to trade shows. We had already developed a repair and return service for them, but there was still a large number of trucks with modules that were not repairable due extensive board damage when the FICM failed. Replacement units were difficult to get ahold of, and some were already damaged, leaving customers in the same situation with no solution in sight.

Our product development team got to work developing a brand new FICM for these trucks. It is built from the ground up, 100% in house, in an effort to restore these trucks back to full functionality.

Putting Our New LLY Duramax FICM to the Test

There has been a lot of time, effort, and testing involved. At Circuit Board Medics, we do not want to put something on the market that is not a fully finished product. Part of that testing has been several lengthy road trips to various trade shows.

Once we got to a point where we were ready for in-view testing, we purchased a 2005 Silverado 3500. That has become the test mule for this project, and we have put some miles on it. The early protypes were driven back and forth from Greenville, SC to Charlotte, NC several times, logging data. We would do side by side trips with both our FICM installed, as well as the original GM unit, to make sure that Circuit Board Medics FICM was performing at least the same as a good factory module.

When we were happy with those results, we decided to put the Circuit Board Medics FICM through a major torture test. We were attending the Ultimate Callout Challenge in Indianapolis at the beginning of June and wanted the FICM to be the focal point of our display, with real world numbers to back it up. We hooked the Circuit Board Medics toy hauler to that Silverado, and traveled from Greenville, SC to Indianapolis, IN. We even had a detour in Ohio to pick up a Honda Acty Kei truck. With the Honda loaded into the RV, we were pulling around 13,000 lbs.

The truck never suffered from a fueling issue during the entire trip to Indy and back to Greenville. We took the data we logged on that road trip and used it to refine the module even more, and tested it on another lengthy haul with the RV. This time from Greenville, SC to Oshkosh, WI for an aviation show in July. Once again, there were no issues whatsoever with the Circuit Board Medics FICM.

The most recent test came in the heat of August, pulling a trailer from Greenville, SC to Pigeon Forge, TN to attend the Jeep Invasion. The truck made itI there and back again with no problems. Again, we logged data to see how the module behaved in varying conditions so that we could perfect the tuning and be confident in the product before we released it to the public.

Built from the Ground Up: Performance, Reliability, and Design

We couldn’t just make a module that performed well, it had to look good, too. Something you would want to pop the hood and show off. We designed a custom housing that functions the same as the original but looks so much better! No more boring, thin, dingy silver. Black anodized aluminum allows for better looks and better heat dissipation.

We can confidently say that our FICM performs just as good as the stock GM units, without the inherent design flaws that caused the original failures, looks dang good in the engine bay; and most importantly, it is readily available.