GP2 will only use DRS in Barcelona race two if certain it will work

The new-for-2015 DRS was not usable for a significant proportion of the race before re-activating in the closing stages.

The DRS appeared not to be working from the start despite race control messages to the contrary.

GP2 boss Bruno Michel would not confirm the nature of the problems, but he said that they are being thoroughly investigated.

"We are looking into it - EM [Motorsport, which produced the system], FOM timing, everybody and we will decide tomorrow morning what we will do," Michel told AUTOSPORT.

"If we are not 100 per cent sure, we will disable it tomorrow and we will not decide until we understand exactly what was going on."

Michel did confirm that the problem was not related to the mechanical side of the system.

"If you are talking about the mechanical side of the DRS, yes it absolutely works otherwise some cars would work and some cars would not.

"If you see all the cars not working and then suddenly all the cars work, it's certainly not a mechanical issue."

The DRS failure did have a significant impact on the race, with those who started on the soft-compound Pirellis, such as race winner Stoffel Vandoorne and DAMS pairing Pierre Gasly and Alex Lynn, making slower progress through traffic after their early stops.

But those who started on the hard tyres and ran long, led by Mitch Evans and Alexander Rossi were able to use the reactivated DRS to make progress late on, eventually finishing second, third and fourth respectively.

Vandoorne, who held on to win even though Rossi did, at one stage, get to within DRS range of him, said that the problem "did not make my life easy".

Lynn, who ran third early on but finished fifth after losing time in traffic, believes GP2 is right not to take a risk with the DRS if it can't be certain it works, but he suspects it will be a straightforward fix.

"As long as it's on for the start of the race that's fine, as in the middle of the race today it was working perfectly," said Lynn.

"But it's really a shame, because the strategy you decide pre-race and the decisions you take in the first laps are all based on the fact that you think there is going to be DRS.

"With the DRS, I would have been able to pass cars more quickly."

A similar problem with the DRS arose during the feature race in Bahrain three weeks ago with less impact on the race, but the system worked correctly in the second.