U.S. safety regulators have opened an investigation into an estimated 61,000 Volkswagen Tiguan SUVs in the United States after receiving complaints about the loss of exterior lighting.

The National Highway Traffic Safety Administration said it opened the preliminary evaluation into the compact SUVs from model years 2009 through 2011 after receiving 26 complaints from consumers about partial or complete loss of exterior lights, including headlights, brake lights and turn signal lights, due to a heat-damaged electrical fuse.

“The reports suggest the problem worsens over time with additional exterior lighting malfunctioning as the problem progresses,” according to the NHTSA document. “Most of the complaints report finding an overheated and melted fuse in the under-hood fuse box. The overheated 30-amp fuse protects, among other things, several exterior lighting circuits.”

There were no accidents or injuries related to the issue listed in the NHTSA document posted online.

A Volkswagen spokeswoman said the automaker is cooperating with the agency’s investigation.

A preliminary evaluation is the first step in a process that can lead to a recall should regulators determine that a manufacturer needs to address a safety issue.