Renault says that Sebastian Vettel's engine problem in Austria was caused by a glitch with the way Formula 1's standard ECU interacted with its own mapping software.
Vettel's hopes of a decent result at the Red Bull Ring were dashed on lap two when his engine lost drive after he pushed the overtake button.
That failure prompted a post-race outburst from Red Bull boss Christian Horner who said that Renault's performance and reliability record was "unacceptable".
But analysis by Renault after the event has uncovered that the French car manufacturer was not entirely to blame for what happened.
Renault's head of trackside engineering Remi Taffin told AUTOSPORT: "We found that after Vettel pressed the overtake button, it selected a map that was not accepted.
"It resulted in it having a torque demand of zero newton metres, so there was no power. It was basically idling.
"We found out in this instant that it was this [overtake] button that triggered it, and that is why we asked [Daniel] Ricciardo to not use it."
SOFTWARE TWEAKS MADE FOR SILVERSTONE
After discovering what went wrong in Austria, Renault has made tweaks to the software for its cars for this weekend's British Grand Prix to ensure there is no repeat drama.
"We have looked into the standard [ECU] software, which obviously showed a problem in the way that some of our maps were not accepted when we go through that line of code for the overtake button.
"When we go a normal way with a usual [steering wheel] selector on a driver map it was accepted. So obviously we have now for here a new software release that will be correcting this. In essence that was the problem."