Steve Carlisle, president and managing director of General Motors of Canada, made the announcement Thursday at the Toronto International Auto Show.
The CAMI plant, which employs about 3,000 workers, currently produces the Chevrolet Equinox and the GMC Terrain. Production of the Terrain is expected to move to Mexico in 2016.
Carlisle said he doesn't expect that the plant upgrade will create any additional jobs at the facility where Unifor, the union representing the workers, say employees have been working six days a week to keep up with demand.
The news comes as workers at General Motors' assembly plant in Oshawa, Ont., which has two production lines, wait for the company to make a decision on its future. GM has said it does not expect to make any decisions until "well into 2016."
But as the loonie continues to drop in value, GM exports to the U.S., where the majority of the vehicles are sold, become more competitive.
"Certainly a lower exchange rate with an outlook that keeps it at that level is favourable," Carlisle said, adding that labour costs are another factor in the decision on the Oshawa plant.
Ontario Economic Development Minister Brad Duguid said while he's pleased with the announcement for the Ingersoll plant, the future of the Oshawa facility remains his "top priority."
"I remain optimistic but, at the same time, realistic about the fact that time is ticking," Duguid said.
The announcement to invest in the CAMI plant in Ingersoll follows a 2013 investment of $250 million in new equipment at the facility. General Motors said it will spend $190 million directly at the plant on equipment and tools and $370 million in vendor tooling with suppliers in Canada.
Unifor national president Jerry Dias said the investment in Ingersoll bodes well for the Oshawa plant as well, as it demonstrates that GM is "not afraid to invest in Canada."
"There is no question that the (Ingersoll) plant is going to continue to run at full capacity," Dias said. "Volumes are going to remain high."