The 2015 Acura TLX has helped turn around Acura's sales year.

Acura dealers have been instructed by Honda to stop selling some versions of the 2015 TLX because the vehicles may roll away they cars have been shifted into park.

The nine-speed V6 version of the TLX is on a stop-sale order from the automaker after it informed the National Highway Traffic Safety Administration (NHTSA) of the problem. Notification of owners will begin on Jan. 6.

Some of the transmission components in the TLX may have been damaged when they were being produced, according to a technical service bulletin issued by Acura. Due to the problem, the shift indicator could indicate that the transmission is in park when it is not, allowing the vehicle to roll away.

Four-cylinder TLX’s use a different transmission, thus are not included in the stop-sale order.

Acura officials said more information will be coming pending NHTSA’s review of the situation, but it’s safe to say a recall is likely to be issued. A stop-sale order is generally a first step in the process of issuing a recall.

The recall is problematic as the brand is counting on the TLX to help revive Acura sales. In fact, when it launched this summer, it was the most expensive ad campaign the brand had ever implemented, according to Mike Accavitti, senior vice president and general manager.

(Acura spends record cash to promote TLX. For more, Click Here.)

Launched in mid-August, the campaign seems to be working. Sales of Acura passenger cars dropped 55% in July and were down 34% for full year at that point. Overall sales for the brand are now in the positive by 0.2% through November. The TLX has played a significant role in that turnaround.

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The Acura sedan lineup rose substantially in November, gaining 29.5% for the month on sales of 6,208 vehicles with the TLX – Acura’s second best-selling model – accounting for 4,233 units sold. This result is in spite of a tight supply of some models in the TLX line-up.

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“The strength of Acura sedans is clearly on the rise since bringing the hot-selling TLX to market in late summer,” said Mike Accavitti, Acura division senior vice president and general manager. “And with demand outstripping supply, we see even more upside potential with TLX and the rest of our sedan lineup in the coming months.”