Thousands of premium brand vehicle models around the world are being checked for a possible fault in automatic transmissions supplied by ZF in Germany.

The company has discovered it supplied a quantity of non-heat treated parking gear gates which quickly deteriorate in use and may cause the system not to engage.

Tests have shown the system may feel like it has engaged and warning lights would appear to confirm the lock was in place, but the vehicle could still roll down a slope such as a private drive unless the electric parking brake was switched on.

The problem was first noticed in America and the National Highway Safety Administration has instigated a recall, starting with the Land Rover LR3 [known elsewhere as the Discovery 3], Range Rover and Range Rover Sport models. It affects less than 2,000 Land Rover models in the US and 4,500 globally.

But the same ZF six-speed box is used by Jaguar, Aston Martin, and BMW, and they have started checks. Aston Martin said the problem affected 88 DB9 Coupe and Volante models worldwide, but numbers are not known for other manufacturers at this time. Inspection and rectification takes about three hours.

The batch of faulty gear plates is thought to have got into the supply chain early in August and to have been fitted consecutively with good plates on production lines.

The NHTSA has also opened an investigation into another product of Ford’s PAG brand group, 39,500 models of the Volvo XC90 SUV, after receiving complaints about battery cables fixture and security. No incidents have been recorded with these.

Robin Roberts