The TV show gave details of three UK Volvo owners whose cars had suffered rough running and sudden loss of power, and suggested that the problem was widespread.
Volvo has since acknowledged it is aware of ETS faults on some models, but insists that safety has not been compromised.
It says it can be fixed by cleaning or changing the electronic throttle module, and that any Volvo drivers who have experienced ETS difficulties should contact its customer relations department at Marlow. New software to correct the fault will be available free of charge to customers from April.
Volvo was reported to have been drafting in extra staff at Marlow to handle calls, but declined to say how many had been received since the programme went out.
One large Volvo dealer AM spoke to said he only had one related enquiry – and that was by email from a customer asking him whether he’d seen the programme.
Another franchised retailer said: “I wasn’t aware there was a problem. And I drive an S80.”
A spokesman for Volvo Car UK says: “Cars with ETS-related problems can display a variety of symptoms such as warning/check lights illuminating, the engine may idle unevenly or the car can go into ‘limp mode’.
“In the latter circumstance the vehicle’s speed will be limited but the car can be driven to a place of safety.”
Ford, Volvo’s owner, says its cars are unaffected as it uses different fuel management systems. The Watchdog claims related to a 1999 V70, another V70 of unspecified age and a C70, also of unspecified age. The owner of one had been charged £650 for a replacement ETM.
The programme pointed out that Volvo Cars North America had voluntarily decided to extend the warranty period for the ETS to 10 years/200,000 miles on 1999, 2000 and 2001 S60, S70, V70, XC70, C70 and S80 with petrol engines; 2002 V70 non-turbo petrol models, and all S60 and V70 Bi-fuel models.
The manufacturer says the US warranty extension was made because of different emissions regulations there and that it was not deemed necessary to offer a similar warranty in the UK.