WASHINGTON — U.S. auto safety regulators have opened five separate safety probes into nearly 1.9 million vehicles manufactured by Ford Motor Co., General Motors and Stellantis, according to documents released Tuesday.

The largest of the probes covers an estimated 1.3 million Jeep Cherokees from the 2014-20 model years. Water may leak into those vehicles and cause the electronic parking brake to activate and stop the vehicle while in motion.

NHTSA’s Office of Defects Investigation said it had received 80 complaints about the issue and opened the preliminary evaluation to “assess the scope, frequency and safety-related consequences of the alleged defect.”

Separately, the agency is investigating 2016 Dodge Journey and Jeep Compass and Patriot vehicles after receiving 127 complaints alleging crankshaft or camshaft sensor failures that may cause the engine to stall while driving.

FCA US, now Stellantis, recalled certain Journey, Compass and Patriot vehicles manufactured between May 9 and July 15, 2016, for the problem in December 2016. NHTSA said vehicles similar to those identified in the recall, but not included in its scope, also may experience the alleged defect. The agency has opened a recall query into more than 289,000 vehicles for further assessment and to determine whether more vehicles should be recalled.

The agency also is investigating Chrysler Pacifica plug-in hybrid vehicles from the 2019-21 model years after receiving 40 complaints alleging a potential transmission malfunction that may cause a stall or loss of motive power. Most of the alleged incidents occurred at speeds greater than 25 mph and required the vehicle to be towed, according to NHTSA. The safety probe covers an estimated 21,348 vehicles.

Eric Mayne, a spokesman for Stellantis, said the automaker is “cooperating with the investigation in accordance with our standard practice.”

Ford, GM probes

In addition, NHTSA has formally launched an investigation into 2021 Ford Bronco vehicles equipped with 2.7-liter EcoBoost engines after receiving three petitions requesting a defect investigation.

NHTSA said it has now received 26 complaints alleging a loss of motor power at highway speeds with no restart. The alleged loss of power is a “result of catastrophic engine failures” caused by the engine valves failing, the agency said in the report. The investigation covers an estimated 25,538 Ford Broncos.

Ford did not immediately respond to a request for comment.

In addition, NHTSA said it is investigating Cadillac XT5 and XT6 and GMC Acadia vehicles from the 2020-21 model years after learning of one reported crash and 11 complaints alleging problems with the rearview camera.

According to the complaints, the rearview camera screens are black or sometimes show a red triangle and a circle with a line through it. The investigation covers an estimated 190,151 vehicles.

GM spokesman Dan Flores said NHTSA has informed the automaker of the investigation.

“The safety of our products is the highest priority for the entire GM team,” he said in an emailed statement to Automotive News. “We are cooperating with NHTSA in their investigation, and GM will continue our own investigations into this issue.

With a safety probe, the agency will assess the scope and severity of the potential defect and other possible safety-related issues.

Most NHTSA investigations start as preliminary evaluations, in which agency engineers request information from the manufacturer, including data on complaints, injuries and warranty claims. The manufacturer also can present its view regarding the alleged defect and may issue a recall.

After the evaluation, NHTSA will either close the investigation or move into the next phase. If a safety-related defect exists, according to NHTSA, the agency might send a “recall request” letter to the manufacturer.