Frustrated over the way Fiat Chrysler Automobiles is handling a spate of recalls since 2013, the U.S.'s traffic safety watchdog will host a public hearing Tuesday to see if the maker of Jeep and Dodge vehicles is taking too long to fix potentially dangerous defects. The hearing by the National Highway Traffic Safety Administration (NHTSA) in Washington, D.C., comes amid mounting complaints from car owners waiting months for recall-related repairs.

“I received a letter approximately a few months after purchasing my vehicle saying that I was eligible for a hitch to be installed for free,” said one frustrated owner of a 1998 Jeep Grand Cherokee in a complaint to NHTSA. But the owner, whose identity wasn’t disclosed by the federal agency, said in the complaint that the dealership said to check back later for available parts.

“That was over a year ago,” the owner said.

On Tuesday, NHTSA will delve into Fiat Chrysler Automobiles’ (FCA) handling of this and 19 other recalls covering about 10.1 million vehicles.

“In recent months, NHTSA has identified problems and expressed concerns with the administration, execution and pace of vehicles being remedied across a number of Fiat Chrysler automobiles,” NHTSA said in a statement. “In addition, the agency has received consumer complaints involving parts-availability issues, lack of notification, difficulty obtaining service appointments, and misinformation from dealers.”

Among those 10.1 million affected vehicles are 1.56 million Jeep Grand Cherokees and Jeep Libertys with fuel tanks that could ignite because they are behind the rear axle. NHTSA’s Office of Defects Investigation says it has found 90 fire incidents, 75 fatalities and 58 injuries linked to the fuel tank issue. 

“They could have used a saddle-type tank, but that may not have fit either, and if it had fit, it would be more costly and would likely make vehicle assembly more difficult,” explains the automotive blog Jalopnik in an article from 2013 when the recalls were first announced, suggesting the design was a cost-savings measure.

The NHTSA online database is filled with consumer complaints from owners of affected Jeep vehicles who say they’ve gotten the runaround from dealers scrambling to acquire enough hitches to fill a backlog. FCA spokesman Eric Mayne told the Detroit Free Press that there are now enough available parts to fix the vehicles. About one in five have been repaired, as many vehicles owners have put off repairs, in part because of past delays or because they feel the risk is low.

At least one recall may be out of the hands of Fiat Chrysler. Nearly 3 million of its cars have been recalled because of faulty air bag inflators manufactured by Takata Corp. The inflators can explode with deadly force, and Takata has been unable to produce an adequate supply of replacement inflators for automakers. On Tuesday, the House Energy and Commerce Subcommittee on Commerce, Manufacturing, and Trade will hold a separate hearing on the Takata air bag recall.

1998-jeep-grand-cherokee-6 The 1998 Jeep Grand Cherokee (pictured here) is one of more than 1.5 million Jeeps that have been the focus of a federal agency investigation centered on the fire risk posed by the position of the fuel tank when the vehicles are rear ended. Fiat Chrysler Automobiles says a trailer hitch can protect the fuel tank from being punctured. Photo: FCA

Here are the Fiat Chrysler Automobiles recalls that the NHTSA is scrutinizing. The Jeep Grand Cherokee is mentioned in eight of these 20 recalls. The Ram 1500 is mentioned in five recalls.

- About 2.9 million Fiat Chrysler vehicles were recalled in December 2014 as part of a massive industrywide recall of vehicles containing faulty air bags made by Takata. The affected units have air bag inflators that can deploy with such force that they spray bits of metal fragments into the cabin, potentially injuring or killing drivers or front-seat passengers. At least a dozen automakers are trying to fix tens of millions of affected vehicles, causing industrywide delays. Click here for the ongoing tally of vehicles affected by the Takata defect.

- About 1.56 million Jeep Grand Cherokee midsize SUVs from model years 1993 to 1998 and 2002 to 2007 Jeep Liberty compact SUVs were recalled in June 2013 to remedy an inordinate risk of fuel leakage and fire in the event the vehicles are rear-ended.  The location of the fuel tank is the primary cause and FCA has agreed to install a tow hitch free of charge that it says will mitigate the higher risk of vehicle fires owing to the location of the fuel tank. The hitch, FCA says, will offer protection in rear-end collisions.

- More than 750,000 Dodge Viper sports cars from model years 2003 to 2004, Jeep Grand Cherokee midsize SUVs from model years 2002 to 2004 and Jeep Liberty compact SUVs were recalled in January to fix a problem that could cause side air bags and seat belt pretensioners to deploy unexpectedly, increasing the chances of a vehicle crash.

- More than 700,000 Chrysler Town and Country and Dodge Grand Caravan minivans from model years 2008 to 2010 and Dodge Journey vehicles from model years 2009 to 2010 were recalled in June 2014 for a problem with the ignition switch. The switch can be bumped out of the on position while the vehicle is in motion, disabling power steering, power brakes and, most importantly, the air bags. The defect is similar to one that has plagued owners of older General Motors sedans. FCA issued two other recalls for the same problem.

- More than 700,000 Dodge Ram 1500, 2500 and 3500 full-size and heavy-duty pickup trucks were recalled in November 2013 to repair a left tie rod assembly that could cause the driver to lose steering ability. The recall covers heavy-duty trucks from model years 2003 to 2008 and Ram 1500s from model years 2006 to 2008. Other Dodge Ram trucks were included in two additional recalls for the same problem.

- More than 650,000 Dodge Durango full-size SUVs and Jeep Grand Cherokee midsize SUVs from model years 2011 to 2014 were recalled in July 2014 to fix a vanity mirror light whose wiring could catch fire.

- More than 640,000 Jeep Commander and Jeep Grand Cherokee midsize SUVs from 2006 and 2007 model years were recalled in July 2013 for an ignition  switch that can be bumped out of the on position while the vehicle is in motion, disabling power steering, power brakes and, most important, the air bags. This is one of three recalls on this list for the same problem.

- Nearly 435,000 Chrysler 300 sedans, Dodge Challenger muscle cars, Dodge Charger sedans, Dodge Durango midsize SUVs and Jeep Grand Cherokee midsize SUVs were recalled in October 2014 for defective alternators that could cause unexpected engine stalls.

- Nearly 340,000 Dodge Durangos and Jeep Grand Cherokees were recalled in February to repair a fuse box that could cause the engine to stall, increasing the chance of a crash.

- More than 290,000 2008 model year Chrysler 300 sedans, Dodge Charger sedans, Jeep Commander midsized SUVs, Jeep Grand Cherokee midsize SUVs and Dodge Magnum station wagons were recalled in September 2014 for an ignition switch that can be bumped out of the on position while the vehicle is in motion. This is one of three recalls on this list for the same problem.

- Nearly 280,000 Chrysler and Dodge SUVs and trucks to fix a rear-axle problem that could cause loss of control. The recall was announced in February 2013. The affected vehicles: 2009 model year Chrysler Aspen full-size luxury SUV; 2009 model year Dodge Durango full-size SUV; 2009-2012 model years Dodge Ram 1500 full-size pickup truck; and 2009-2011 model years Dodge Dakota midsize pickup truck.

- Nearly 270,000 Dodge Ram 1500 full-size pickup trucks from the 2008 model year and Dodge Ram 2500 and 3500 heavy duty trucks from the 2008-2012 model years were recalled in November 2013 to repair a left tie rod assembly that could cause the driver to lose steering and crash. This is one of three separate recalls related to the same vehicles and same problem.

- Nearly 260,000 2005 Dodge Ram 1500 pickup trucks were recalled in December 2013 to fix a problem with the rear axle that can cause drivers to lose control of the vehicles.

- More than 230,000 Jeep Grand Cherokees from model years 2014 and 2015 were recalled in January to fix a problem that can cause side, window and roll-protection air bags to deploy unexpectedly, increasing the likelihood of a crash.

- More than 54,000 Dodge Dakota midsize pickup trucks, Dodge Ram 1500, Dodge Ram 2500 and Dodge Ram 3500 from the 2006-2007 model years were recalled in December 2014 to fix a defective manual transmission. The defect can cause the clutch to fail, increasing the chance of a crash. The recall includes some Mitsubishi Raider pickup trucks that were built by FCA.

- Nearly 40,000 Dodge Ram 4500 and Dodge Ram 5500 heavy-duty pickup trucks from the 2008-2012 model years in a November 2013 recall to repair a left tie rod assembly that could cause the driver to lose steering.

- More than 25,000 2015 Chrysler 200 sedans were recalled in February to repair a defective parking lock. The problem could lead to cars rolling away unexpectedly even if the parking pawl is shifted to the “Park” position, leading drivers to believe the car is locked and not capable of rolling away.

- Nearly 12,000 2015 Dodge Challenger muscle cars were recalled in November 2014 for a problem with the instrument panel that could become inoperative, increasing the possibility of a crash.

- Nearly 1,900 2015 Dodge Challengers and Dodge Chargers were recalled in February to replace a defective fuel hose that can leak and cause a fire.

- About 1,400 Dodge Viper sports cars from 2013 and 2014 model years were recalled in March because the doors can open unexpectedly.