The recent exposure of a series of problems involving products made by foreign manufacturers should cool Chinese consumers' enthusiasm for overseas brands and prompt domestic watchdogs to increase their oversight of the product quality.

The automaker Volkswagen Group China and its joint venture partners have announced that they will recall more than 380,000 vehicles in China after China Central Television's annual broadcast to mark World Consumer Rights Day on March 15 reported some of the company's gearboxes were defective, causing unanticipated changes in speed while driving. The models to be recalled include the popular Passat, Sagitar, Golf, Touran and others made at its China-based ventures, as well as some imported models such as the Audi A3.

The flawed gearbox has cooled some of the passion Chinese drivers had for the German brand.

Another company caught in the CCTV spotlight was the electronics giant Apple, which was criticized for discriminating against Chinese customers by offering lower levels of service.

The exposure of the problems involving the two popular foreign brands will dent their market share in China and be a drag on the government's efforts to expand domestic demand and build a consumption-led economy.

Volkswagen has aggressively expanded its operations in China, and now sees the country as its largest single market, while Apple is looking to the Chinese market to revitalize sluggish growth.

However, the market shares of McDonald's and KFC have declined in China since last year's annual investigative program by CCTV revealed they were using ingredients that were past their expiry date. This should be a reminder to foreign brands that have their eyes fixed on Chinese market that they cannot cheat or mistreat consumers.

The jewelry company Chow Tai Seng was another well-known brand named by the CCTV special, which investigates the malpractices of both foreign and domestic companies. Chow Tai Seng was revealed to have adulterated some of its gold with iridium, a metal which is akin to gold but much cheaper.

Redoubled efforts are needed to improve the quality of goods and services as a way of keeping the country's slowed consumption momentum from further losing steam.