Toyota has recalled its most popular car, the Corolla — on the same day a law firm has announced it is investigating a class action against the top-selling HiLux ute.

Australia’s number one brand — which dominates the local market, accounting for almost one in five new car sales — will recall 2640 new Corollas due to a faulty automatic transmission.

Meanwhile, Bannister Law is looking at a class action involving Australia’s most popular vehicle, the HiLux, for problems associated with its diesel particulate filter.

It’s an embarrassing development for the company, which sells on its reputation for quality, durability and reliability. The latest issues come on the back of the Takata airbag recall, which affected almost 600,000 Toyotas in Australia, more than any other brand.

The recall of the Corolla, the world’s best-selling car of all time, focuses on its continuously variable transmission (CVT).

The transmission differs from a conventional automatic in that it doesn’t have the usual stepped sequence of gears, working instead via pulleys and a belt.

The recall only applies to the new Corolla launched in August and only involves the 2.0-litre petrol powered auto versions. Hybrid models are not affected.

Toyota says that in certain circumstances the car’s torque converter may be damaged, causing the CVT automatic transmission to lose power and heightening the risk of a crash.

There have been no known instances or injuries in Australia.

The class action, which also relates to diesel versions of the Toyota Prado and Fortuner SUVs, centres on claims that the vehicles’ diesel particulate filters are defective and do not burn off particulate matter in the course of normal urban driving.

The particulate matter can then build up within the filter, causing a blockage and resulting in “excessive emission of foul smelling white fumes from the exhaust”. Bannister Law claims customers have also reported excessive fuel consumption.

It claims the problem could lead to increased engine wear and tear.

Toyota has written to customers offering to clean the filters and replace any that may be damaged. It is also retrofitting a switch to perform a manual burn off in the filter.

But Bannister Law argues that the problem has been known for a number of years, causing customers “unnecessary inconvenience and expense”.

It says a claim could encompass repairs not covered under warranty, loss of income while vehicles are off the road, higher fuel costs, loss of engine power and possible higher depreciation due to the fault.

The firm says it is investigating possible contraventions of Australian consumer law relating to misleading and deceptive conduct.

In a statement, Toyota says:

“We are aware that some HiLux, Fortuner and Prado vehicles sold between June 2015 and June 2018 have the potential to develop a Diesel Particulate Filter (DPF) issue.”

It says the company launched a customer service campaign in October.

“All customers with potentially affected vehicles have been, or are in the process of being, contacted by letter and are requested to make contact with their closest/preferred Toyota Dealer.”

It says dealers will reprogram the engine control module, ensure the DPF has been regenerated and conduct a smoke test. If it fails the test, the DPF will be replaced.

“All inspection work and replacement, if required, will be completed free of charge to the customer.”

Owners can call 1800 869 682 for more details.

Replacement parts for the Corolla have been ordered and Toyota Australia anticipates them being made available in the first half of next year.

It says owners should take their vehicle to their local dealer when parts are available to have the transmission replaced at no cost.

The repairs should take about 10 hours to complete.

For more information on the Corolla recall, owners can call 1800 987 366.

Bannister Law says information on its class action is available at http://bannisterlaw.com.au/toyota-class-action-investigation/.