BMW Repair: Brake blocked, jj jj, bmw 325i

Question
Hi Evan,

I have a BMW 325i 2006 with automatic transmission. I have been having the following problem and the service does not seem to know what causing it:

Every now and then the brake gets blocked and I can't start the engine. Because the brake is blocked, I can't move the transmission to N either. Therefore, I can't even push it outside of my garage for the tow truck to lift it. Then I come the following day, and sometimes the brakes suddenly unblock. I took it to the service and they could not tell me what it is. It has happened 4 times already and I wonder if I should have BMW replace the vehicle with a new one.

Thanks for your help,
JJ  

Answer
JJ, I am not exactly clear on what the 'brakes get blocked' statement means. The brake pedal physically get blocked and won't move? Or you just can't start the car because you feel that the brake pedal input is not being recognised by the car? Does the key lock in to the holder?Does the foot on the pedal logo apear on the dash? If you have the key on in second position (All dash functions on and a/c fan controls work,i.e. two press of the start button without pressing brake pedal). Now when the system is acting up press the brake and the start button. What happens? I sympathize with you and your service depot. Intermittent problems are very hard to solve. Do you get all the dash light that you normally get when trying to start the car? Can you move the shifter with the brake pedal depressed and key in second position? If so does the LEDs change correctly with the gear shift position. If you can get the gear selector in Reverse or Drive can you remove the key from the key holder? Please provide me answers to these questions. I have seen this problem before, but need more info to help out. Please take the time to answer all of my questions in detail if you want help.
-Evan