On top of last week’s 1.8 million car recall for ignition switch checks, General Motors on Monday said it will recall about 636,000 model year 2002-03 midsize sports utility vehicles to check the windscreen wiper system.

The vehicles: 2002 Chevrolet TrailBlazer and TrailBlazer EXT, GMC ENVOY and Envoy XL, and Oldsmobile Bravada SUVs built between October 2000 and June 2002. Some 2003 TrailBlazer and TrailBlazer EXT, Envoy and Envoy XL, and Bravada SUVs built between April and November 2002 are also included, along with some 2002 Isuzu Ascenders.

Of the total, about 580,000 are in the United States and approximately 31,000 are in Canada – the rest are outside North America.

The repair programme does not begin until the third quarter of 2004 when owners of affected vehicles will be asked to take vehicle to dealers who will cover a vent hole in the windshield wiper module vent hole with a patch, inspect the wiper motor, circuit board, and electrical connector for signs of water intrusion and/or corrosion and replace parts as required, free of charge.

GM said there have been two reports of crashes related to the wiper fault, but no injuries or fatalities.

In some vehicles, water can enter and cause a short circuit or corrosion of the components within the wiper module and there have been reports of the wipers not working properly. GM suggests owners of affected vehicles have them checked immediately but adds that most probably will not experience any problems, and should wait for a recall notification letter.