WASHINGTON (Reuters) - Boeing Co BA.N and the Federal Aviation Administration (FAA) confirmed on Sunday they are reviewing a wiring issue that could potentially cause a short circuit on the grounded 737 MAX.

FILE PHOTO: An aerial photo shows Boeing 737 MAX airplanes parked on the tarmac at the Boeing Factory in Renton, Washington, U.S. March 21, 2019. REUTERS/Lindsey Wasson/File Photo

Boeing spokesman Gordon Johndroe said Sunday the U.S. planemaker “identified this issue as part of that rigorous process, and we are working with the FAA to perform the appropriate analysis. It would be premature to speculate as to whether this analysis will lead to any design changes.”

The New York Times reported Boeing is reviewing whether two bundles of wiring are too close together, which could lead to a short circuit and potentially result in a crash if pilots did not respond appropriately.

The FAA said in a statement Sunday the agency and company “are analyzing certain findings from a recent review of the proposed modifications to the Boeing 737 MAX.” The agency added it will “ensure that all safety related issues identified during this process are addressed.”

Boeing is currently working to design separating the wiring bundles if necessary and conducting extensive analysis to establish if the electrical fault could occur in a real-world scenario, a company official said.

Officials said the FAA had directed Boeing to complete an audit in December. The wiring issue could push back the return of the MAX, the officials added. Reuters has reported previously the FAA is not likely to approve the plane until at least February and might not until March or later.

The FAA flagged the wiring issue as potentially “catastrophic.” It is possible other protections like shielding, insulation and circuit breakers could prevent the short circuit, a company official said.

Boeing will halt production of the 737 MAX this month following the grounding in March of its best-selling plane after two fatal crashes in five months killed 346 people.

Last month, Boeing’s board fired Chief Executive Dennis Muilenburg after repeatedly failing to contain the fallout from the crashes that tarnished its reputation with airlines and regulators.

The crisis has cost Boeing $9 billion, and has hurt suppliers and airlines.

Boeing is struggling to mend relations with the U.S. and international regulators it needs to win over to get the jet back in the air.

Separately, U.S. and European regulators are expected to return to Iowa this week to review a software documentation audit of the 737 MAX that was not completed last year, officials said Sunday. FAA and the European Union Aviation Safety Agency are scheduled to meet in Seattle this week and then return to Rockwell Collins facility in Cedar Rapids, Iowa next weekend to review the audit.