Toyota has condemned arch-rival Honda for what it says is a manipulation of a new rule requiring engines to last for two entire race weekends.
Toyota and Honda are bitter rivals in F1 and road cars
BAR-Honda retired both cars on the last lap in Australia so they could fit new engines for Sunday's Malaysian race.
"Exploitation of such grey areas is against our understanding of racing," said Toyota engine boss Luca Marmorini.
"Our drivers did not score points in the last race, but we passed the flag out of respect for the new rules."
The rules say that drivers who fail to finish a race can fit a new engine for the following event without incurring a penalty.
In other circumstances, a team changing an engine will be put back at least 10 places on the grid.
Toyota's drivers Ralf Schumacher and Jarno Trulli finished ninth and 12th in Australia, while BAR's Jenson Button and Takuma Sato were classified 11th and 14th after the team called them into the pits at the end of the last lap.
Marmorini added: "We fully accept the spirit and intention of the 2005 engine regulation and we believe that if we are to challenge for points regularly, we must finish the race and that means having an engine to last two races."
Toyota and Honda are bitter adversaries in their home road car market, and it is of vital importance to each that they are at least the best Japanese team in F1.
BAR-Honda team boss Nick Fry said in Australia: "Our reading of the rules is that if you fail to finish, it then gives you the opportunity to change your engine because you've effectively taken the penalty in the race you failed to finish.
"So we've taken advantage of that and, if we choose to do so, fit a new engine for Malaysia."