And Fiat says it doesn't include senior leadership.
FCA's initial investment in Warren for the Wagoneers was announced in January 2017.
What's more, FCA said it would pay a $2000 bonus to 60,000 hourly and salaried employees, which the company said was made possible by a huge corporate tax cut enacted late past year.
The investment follows a dramatic jump in Fiat Chrysler stock amid optimism about its product lineup being revamped with fresh trucks and sport utility vehicles.
$1 billion in the south plant of the Toledo Assembly Complex to prepare the facility to produce an all-new Jeep truck, and in the Warren Truck Assembly Plant to modernize the plant to build the all-new Jeep Wagoneer and Grand Wagoneer. Trump reiterated a threat to pull out of the trade accord on Thursday, a day after Canadian officials said they viewed the odds of withdrawal as rising.
The move will mean 2,500 new jobs. That's where the $1 billion plant investment comes in, billed as a modernization of the MI facility.
The special bonus will be paid to all eligible employees of the FCA automotive and components operations in the US, the OEM added.
The Italian-owned FCA's announcement comes one day after Japanese-owned Toyota and Mazda said it will build an assembly plant in Alabama that will create approximately 4,000 jobs in the Huntsville area.
The plant investment actions announced today are subject to the negotiation and final approval of incentives by state and local entities.
Miguel Ceballos, FCA spokesman for Mexico, said the company in 2018 and 2019 expects more growth in Mexico, and the moment it stops producing the Ram Heavy Duty pickups it will start to produce the new commercial vehicle, "which still does not have a name", Ceballos said.
"It is only proper that our employees share in the savings generated by tax reform and that we openly acknowledge the resulting improvement in the USA business environment by investing in our industrial footprint accordingly", Chief Executive Officer Sergio Marchionne said in a statement. He says employees should also share in the tax savings.