McLaren has more than enough headaches in the technical department after the team's dire showing in the Australian Grand Prix at the weekend, the first race in the 2013 F1 world championship.
But now they've come under fire from rival team boss Christian Horner, who has suggested that it was a vital component developed and delivered by a McLaren subsidiary which directly caused Mark Webber's dreadful start in the race at Albert Park, Melbourne.
"Mark's problems were hugely frustrating because it was an ECU issue that is obviously supplied by a third party," said the Red Bull team principal. "I'll let you guess who that is!"
The ECU - the electronic control unit - is the brains of the car and handles all the telemetry systems in an F1 car. All the teams use a standardised sealed unit provided by McLaren Electronics Systems (MES), which has supplied ECUs to F1 and many other motorsports series around the world for a number of years.
The previous ECU system used in F1 had been regarded as "bulletproof" in terms of reliability. However, this season sees the introduction of a new generation of ECU components as part of a major change in technical regulations coming through for 2014, specifically relating to a new generation of energy recovery systems (ERS) and the introduction of V6 engines to the sport.
Red Bull was not at all happy when that new unit for their #2 car failed, depriving them of access to critical data immediately before the start of the race in Melbourne.
"We lost all telemetry on the formation lap, so we couldn't do the preparation you need to for the start. It totally messed it up," fumed Horner of the problems facing Webber and his car crew. "He and the engineers were completely blind."
Not only did Webber lose six spots off the grid as a result of the launch set-up issues, the Australian also went half the race without being able to use his KERS boost system - something else that came down to the issues with the McLaren ECU.
"The ECU issue also shut down KERS, so by the time we had reset the whole system, it lost Mark the start and early ground," revealed Horner. "It's something they need to get on top of because there were a lot of issues during testing," he added, giving a direct warning to McLaren that he was not happy with the situation.