I drove the car last night and early this morning with no issues. Parked it in the garage. Several hours later, I went to get in the car. Press my foot on the pedal to start the car and it would not start. I noticed that the brake pedal sank to the floor. I tried this twice, the car would not start. I checked the brake fluid and it is at normal level. What could be the issue. 2008 GS 350. No engine light, no warning lights. Key is detected. Note on dashboard says to press the brake to start the car. No luck. Is there any advice.??

 

If the brake pedal sank to the floor, that could be a bad brake master cylinder, but that wouldnt stop you from not starting the car. What will stop you from not cracking it over is the brake pedal sensor, and it does seem like it is not registering from the text on the dash.

Did you first tried jump starting the car just to make sure its not a low voltage issue? If the voltage is ok, and battery terminals are good and solid. I would start by pushing the brake pedal and seeing if the brake lights work. If they dont, I would suspect the brake pedal sensor. You can crawl under the dash, shine a flash light at the end of the brake pedal. You should see a sensor make sure it is plugged in and not broken or twisted

 

I had to go to work, so i used another car. But before i left, i tried it again. And for some reason, the brake pedal was firm. I had a green light on the start button and it started. (The 1st 2 times, the start button was orange). ....I didnt drive it, bcuz i was puzzled... i just got home about 4am. And to sooth my curiosity, i went into the garage to check. This time, the pedal was still firm and i again had a green start light. It started.... i checked for leaks on the calipers and around the master cylinder. All was dry. And fluid looks very clean. (it may be failing). I'll keep an eye on it.. i will look at the sensor under the dash to see if its damaged. Tomorrow,.. thank you for your advise