Fernando Alonso has rejected McLaren's claims his pre-season testing crash was not caused by mechanical failure.
The double world champion, who missed the opening race in Australia earlier this month with concussion following the accident on 22 February, insists it was caused by a steering problem.
The Spaniard's comments reopen the debate about why the incident happened.
McLaren have said they found no evidence that anything went wrong with the car.
- denied reports he had been knocked out following the crash
- said he did lose consciousness but that was down to medication
- rejected claims he thought he was 15 when he regained consciousness
- said speculation about his health was not helped by statements by McLaren and his management
- rejected suggestions from Ron Dennis that his car may have been affected by a gust of wind.
The 33-year-old had to pass a fitness test to convince F1's medics he is fit enough to race again this weekend.
But he was keen to set a few things straight about his high-profile crash.
Alonso said the steering "locked to the right" as he rounded Turn Three at the Circuit de Barcelona-Catalunya.
"I approached the wall, I braked in the last moment, I downshifted," he said. "After the hit, I was kissing the wall for a while. I switched off the radio and then the master switch and then the Ers (hybrid system).
He explained the fact that the team could not find evidence to support the car locking to the right was due to shortcomings in McLaren's data acquisition on that part of the car.
The team said they have fitted an extra sensor to improve their data capture.
Alonso also explained that he lost consciousness only in either the ambulance or at the circuit medical centre as a result of medication and that he remembered the whole accident.
"I was perfectly conscious at that time. I lost consciousness in the ambulance or clinic but the doctors say this is normal for the medication and the checks they put on you for the MRI," he said.
"Everything was more or less normal concussion. I went to the hospital in good conditions.
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"There is a time I don't remember in hospital from two o'clock to six o'clock in the afternoon that day but that is normal due to the medication. Then everything was normal.
"I didn't wake up in 1996, didn't wake up speaking in Italian; all these things that were out there. I remember the accident and everything from the accident."
Alonso said some of the official explanations about the incident given by both McLaren and his own management were "not a help".
Among the early information relayed by the team was that the car might have been blown off course by strong gusting winds.
He added: "Some of the confusion comes from the early quotes when the pressure was very high and I was in intensive care and there was an urgency to say something."
Alonso is likely to be at the back for his return as McLaren have started the season in uncompetitive form due to a lack of power from their new Honda engine.
His former team, Ferrari, were the second best team after Mercedes at the first race but Alonso said he had no regrets about his decision and still had faith McLaren would take him to a third world title.
"I'm one of the happiest people in the world," he said. "I have a challenge in front of me. A tough challenge, clearly. I understand we are too far back and will be heavily criticised and that will be fair.
"It is difficult but it is going to taste better when we do it."
|Chief F1 writer Andrew Benson|
|"Fernando Alonso set Formula 1 on fire with his performance in the official news conference ahead of the Malaysian Grand Prix.|
|"After the tumultuous season he spent at McLaren in 2007, everyone was waiting for some kind of fissure to appear in their relationship this time around. But no one was expecting it to happen before he had even raced the car.|
|"McLaren say their exhaustive analysis of Alonso's crash in pre-season testing has thrown up no evidence of a car failure, although they have been careful not to say definitively that there was not.|
|"But rather than sticking to the company line, Alonso chose to say - in response to the very first question on the subject - that the car 'definitely had a steering problem'. The interesting thing is what happens next.|
|"Later in a remarkable, eloquent, clear-spoken and good-humoured performance, Alonso said he was 'the happiest man in the world' to be at McLaren-Honda despite their poor start to the season.|
|"But can the relationship survive for long after this? It is going to be a fascinating few months."|