Toyoharu Tanabe believes the power unit issue that befell Brendon Hartley during practice for the French Grand Prix was unrelated to the one Pierre Gasly suffered during the Canadian Grand Prix weekend.

Hartley’s saw his weekend at the Circuit Paul Ricard compromised when he stopped on track in second practice on Friday afternoon, and starting from the back of the grid he could only move to fourteenth by the chequered flag.

Honda will investigate the reasons behind the New Zealander’s problem, but Tanabe, Honda F1’s Technical Director, believes the problem was not the same as Gasly experienced two weeks ago.

“We couldn’t tell anything specific from our inspection here, we needed to wait,” said Tanabe to Motorsport.com. “We will start analysing from Tuesday in Japan. The countermeasure depends on the type of the failure – quality, or spec.

“We need to have a report from our base inspection, then we can understand how long it will take, or how difficult.

“We had two issues but it looks like they are slightly different. I cannot tell you if different is better, or if different is bad for us.

“But we need to find the root cause of this weekend’s failure and try to fix it for the future.”

Tanabe admitted the whole weekend in France was a complicated one for Toro Rosso and for Honda, with Gasly being eliminated in an opening lap clash with fellow Frenchman Esteban Ocon at turn three.

“This was a complicated weekend and it was extremely disappointing for us and also for all the French fans, that Pierre’s race was over just a few moments after the start,” said Tanabe.

“Brendon, who started from the back of the grid because of the penalties incurred, moved up the order as others fell out and he also passed a few cars.

“A race to forget, but at least we can try and do better, starting this coming Friday in Austria.”