The power-unit supplier, which has played a key role in the success of Red Bull and Sebastian Vettel over the last four years, endured a disastrous first test in Jerez last month.
Red Bull completed just 21 laps over the four days due to a series of problems, most due to Renault, which has struggled to adapt to the new regulations and introduction of the 1.6-litre turbo-charged V6s.
The French manufacturer encountered hardware and software woes to such an extent it has led to suggestions Red Bull are already on the lookout for a new supplier for 2015.
Remi Taffin, head of Renault Sport F1 track operations, is hopeful a lot of the faults have been corrected ahead of the second test that begins in Bahrain next Wednesday.
"We left the first test with a lot to do on our side, mainly facing hardware and software issues," said Taffin in a conference call.
"With regard to the hardware we are now confident the problem we had in the first test has been solved and we will be in a position to go out in Bahrain without all these issues.
"As for the software we've improved our level. We're still behind our initial schedule, but now beyond what we would have done in the first test.
"Again we should be okay in Bahrain to go out on the first day with a car that should be working.
"We are ready to do what we would have liked to have done in the first test, which is to properly test the power unit and give our customers a way to discover their cars."
Red Bull, along with fellow Renault customers Toro Rosso, Lotus and Caterham will naturally face anxious moments when their cars take to the Sakhir circuit.
If there is a repeat of the incidents that unfolded in Jerez then Red Bull and Vettel's hopes of a fifth straight crown could be scuppered before the season starts in Melbourne in four weeks' time.
Taffin added: "There is development on the hardware and software. It's not a fatality, but that's where we are.
"We are trying do everything at the same time, but then sometimes we have to prioritise so it's not easy to have everything altogether at once."
The suggestion is the various components within the power unit are so complicated they are not 'talking to one another' via the software.
"It's not a communication problem. It's how you make them work together," added Taffin.
"It's not like one is not talking to the other, it's basically the language they use.
"We have to get this working, and what we hope to achieve on the first day in Bahrain.
"If the work we have done recently is okay, which we think it is, then we should see the difference in Bahrain, with cars out on track, which will mean we have solved the problem."
With regard to Renault's current level of competitiveness compared to Mercedes and Ferrari, Taffin added: "We're still behind schedule, but it's not a question of months.
"We are at least where we would have sought to be for the first test, so maybe now we are three weeks behind, and now we are on a recovery plan.
"We're now going to go into Bahrain with what we would have liked to have finished the first test with.
"As for our rivals, let's put it this way, they are probably four days ahead of us as they had a proper test in Jerez, and we didn't."