US safety regulators are probing some 1.2 million Chrysler vehicles to determine whether potential ignition-switch defects could result in engine stalls and the possible non-deployment of air bags.
The National Highway Traffic Safety Administration (NHTSA) has said the investigations involve older Jeep, Dodge and Chrysler models.
One NHTSA investigation of Chrysler, involving about 525,000 Jeep SUVs made between 2005 and 2007, focuses on whether a nudge from a driver's knee can push the switch to the "off" or accessory position -- turning off the engine and potentially disabling air bags in the event of a crash.
The other, involving 700,000 Chrysler Town & Country and Dodge Grand Caravan minivans and Dodge Journey crossovers from model years 2008-2010, focuses on whether switches can be turned off when driving on rough roads.
The new Chrysler investigations signal that problems surrounding faulty ignition switches, which could cause air bags to fail, might hit other automakers besides Chrysler and GM.
The NHTSA is investigating similar issues at GM, which has recalled over 20 million vehicles this year, mostly in the US. Close to 6.5 million of these were recalled because of ignition switch faults.
The regulator, which administers safety recalls, said on 18 June the Chrysler probes resulted from its recent "communication with automotive manufacturers and suppliers regarding airbag design and performance related to the position of the vehicle ignition switch."
"As part of NHTSA's broader efforts to evaluate this issue, the agency examined all major manufacturers' airbag deployment strategies as they relate to switch position."
Chrysler, owned by Italy's Fiat, said it was "awaiting additional information" from NHTSA and that it will cooperate with the investigations.
German automaker Daimler, Chrysler's previous owner, said on 18 June it is unaffected by the NHTSA investigations.
General Motors is being grilled by Congress about disregarding the safety of its customers after emails from 2005 revealed that a GM employee had warned a "big recall" may be needed because of an ignition switch fault, which is only now being addressed by the company.
Emails made public on 18 June showed that GM employee Laura Andres in 2005 wrote to engineers and to the then vice president of North American engineering Ed Koerner, warning that a 2006 Chevy Impala Special car she owned had suffered an engine stall when moving between a paved road and gravel.
Andres' email added that a technician told her the problem could be with part of the ignition switch. The 2006 Impala was recalled only on 16 June.