Possible rear-seat defects in some Chrysler minivans are being investigated as the result of the death of a 2-year-old boy in a crash, a government spokesman said yesterday.

The National Highway Traffic Safety Administration probe was prompted in part by a coroner's complaint that the seats are unsafe.

Chrysler spokesman Tom Jakobowski said the company was cooperating with the investigation.

"We have 2 million-plus minivans out there and we know of no specific problems with the rear seats," Jakobowski said. The vans comply with federal standards for rear seat strength, he said.

The government probe will focus on Dodge Caravans and Plymouth Voyagers manufactured in the 1986-89 model years, spokesman Tim Hurd said. It's classified as a preliminary evaluation, which consists mostly of paperwork.

A spokesman for the Center for Auto Safety, a watchdog group founded by Ralph Nader, said the federal standards were inadequate.

"That a seat as flimsy as the one in Chrysler minivans meets the minimum requirements ... shows the standard offers little protection," spokesman Mike Johnson said.

If evidence of a widespread problem is found, the probe will be upgraded and government engineers will study the possibly defective parts. A recall for repairs could be ordered.

Chrysler makes more than half the minivans sold in the United States. They are marketed as the Dodge Caravan, Plymouth Voyager and Chrysler Town & Country.

The government has received six complaints about the minivans involving three accidents, four injuries and one death, Hurd said.