June 13, 2022


Chris Weiss Headshot

Guest Contributor
Knapheide Vice President of Engineering

In the work truck industry, our primary tasks involve putting equipment in and on vehicles so that our customers can do their jobs safely and efficiently. So much discussion happens internally and externally during this process surrounding certification of those vehicles. The knowledge of this subject by the players involved ranges from novice to expert. For that reason, I feel compelled to publish a series of posts talking about some of the basic topics and challenges we have in creating a properly certified upfit.

The National Truck Equipment Association (NTEA) is a great association resource to validate any questions surrounding vehicle certification.

The simple answer to why we have to certify and label our work truck upfits is it is federal law. CFR 49 Part 571 lays out the vehicle safety standards commonly referred to as the Federal Motor Vehicle Safety Standards (FMVSS) that we have to comply with. No matter what stage of manufacturer you are (incomplete, intermediate, final or altered), there are requirements outlined in FMVSS.

The second (and more important) reason why we have to properly certify and label our work truck upfits is liability. Following all the FMVSS standards and processes will minimize the liability not just for the manufacturer/upfitter but for all the entities involved in the upfit process including vehicle manufacturer, vehicle dealer, FMC, and end user.

We all win if this process if followed correctly.


Vehicle Certification Basics: Pass-thru Certification

One of the more confusing parts of dealing with upfitting vehicles, and especially explaining it to your customers, is the concept of pass-thru certification. When an upfitted vehicle is completed, no matter what the stage type used, a certification label must be placed on the vehicle stating it meets all applicable FMVSS standards for safety. Many FMVSS standards require extensive analysis and testing to verify compliance including very burdensome crash testing. That is cost and time prohibited to complete all that work by every upfitter for every vehicle.

The fastest and easiest way to verify this FMVSS compliance for upfits is to use pass-thru certification. When the vehicle OEMs develop their vehicles, they complete all the necessary and costly work to verify FMVSS compliance. In the example of incomplete vehicles, the OEMs also provide an incomplete vehicle document for that vehicle which provides guidelines and limitations which, if the upfitter follows that direction, can state that the final vehicle is in compliance with FMVSS standards without having to do any additional analysis or testing. This incomplete vehicle document, or IVD, is very detailed in listing weight and dimensional limits as well as what vehicle components cannot be modified in order to maintain compliance. There is a specific version of the required final stage certification label that states the vehicle complies with all FMVSS standards because the vehicle was completed in accordance with the vehicle manufacturer’s IVD.

It is possible to still complete an upfit without explicitly following the IVD guidelines but this requires the upfitter to conduct their own analysis or testing to assure FMVSS compliance. If you are talking about a standard that requires crash testing for validation, that probably isn’t going to happen. That is why following the IVD guidelines is so important. More important is working with the customer so they understand what can and cannot be done on their upfit in order to be compliant but also reduce liability risk for all parties involved.


Watch our blog for more in this series on vehicle certification.

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