Mercedes boss Toto Wolff admitted that the problems the W05s struggled with in Canada could become a regular issue if they aren't able to analyse the cause of the mysterious drop in power both cars suffered.
Nico Rosberg and Lewis Hamilton had again pulled away from the field over the first half of Sunday's race in Montreal, but both cars suffered a power drop that saw them lose a couple of seconds per lap to the chasing field.
Ultimately the problem led to a failure of the brakes for Hamilton, who had to retire for the second time this season, while Rosberg hung on to second place behind Daniel Ricciardo.
"We had, at exactly the same time, a failure of the engine control systems on the ERS, the NGU-K," Wolff confirmed to crash.net.
"We had a peak in temperatures that wasn't on our priority list and it just happened all at the same time.
"They were exactly the same power units, racing at exactly the same pace and had exactly the same temperatures. In that particular part of the NGU-K, we saw temperatures that were higher than expected, but we weren't aware that they could have such a detrimental effect - the NGU-K just shut down and we couldn't reset it.
"We know where we are critical and where it is important and, in that case, it was something we didn't spot before, so it's just another part we have to analyse and understand. I guess this can happen but the consequence was detrimental to the whole car."
Wolff ruled out the heat in Montreal or the close racing between Rosberg and Hamilton as possible causes of the problem.
"We don't know yet [if there is potential for a repeat] because all we know is that we had a peak in temperatures in the system that we didn't expect to be as crucial as it was," he said.
"It's kind of bizarre, but it shows that we are being so diligent with all the systems and then you have a little glitch which you don't judge as being really important but just shuts down the whole NGU-K."