[THE INVESTOR] GM Korea, the South Korean unit of US carmaker General Motors, will recall 15.056 Chevrolet Orlando compact multi-purpose vehicles for emission-related problems, the Environment Ministry said on Aug. 21. 

The order affects Orlando units using the 2.0 liter LPG engine produced between May 6, 2011 and Oct. 7, 2013. 

According to the ministry, the defective cars have been found to emit carbon monoxide beyond permissible levels. After testing 10 Orlando MPVs, all vehicles emitted more than 1.847 grams per kilometer of CO gas, higher than the 1.06 g/km limit set by Seoul. 

The colorless and odorless gas is toxic and is tightly regulated by environment and health authorities. 

In addition, tests showed the nonmethane organic gas released by the MPVs exceeded the 0.025 g/km limit. NMOG refers to the sum of all organic air pollutants, excluding methane gas.

According to GM Korea, the buildup of carbon within the throttle body is reason for the problem. This defect triggers incomplete combustion that causes the excessive release of CO and NMOG. 

The GM Korea will replace emission control software free of charge starting on Aug. 22 at its service centers nationwide. 

(theinvestor@heraldcorp.com)