After doing a quick search I canít seem to find someone who has asked this question before so here goes.
I purchased a 2009 Mazda 6 Grand Touring with everything available except the navigation system. It is a great car except for a problem I have been experiencing with the brakes.
The brake appears to be automatically engaging itself while driving. I will not have my foot on or even near the brake pedal. In some instances my foot will be on the gas, yet the brakes appear to also be and stay engaged.
It begins as a slight vibration through the car and gradually increases. I have to depress the gas pedal more just to maintain the same speed. Eventually the vibration becomes so significant that you canít see out the rear view mirror due to it shaking so badly. If I depress the brake and then release, the vibrations stop.
I have also noticed that I cannot turn on cruise control at times. However, when this happens, I can depress the brake and release, and then engage cruise control. This also makes me think it is the brakes since I know you canít engage cruise control when your foot is pushing on the brake.
Lastly, my wife has traveled behind me in our other vehicle and noticed that my brake lights will turn on and remain on for extended periods of time. The will remain on until I am forced to brake, such as a stop sign or light. By extended periods of time, I mean at least 10 miles or more.
I had one incident when every indicator on my dash related to brakes went off. This occurred right after the vibrations became so significant that my car jolted. Basically every braking system in the car shut off and left me with manual brakes only. When I brought it to the dealer, they stated that they felt the battery ground wire was loose and tightened it. They then reset my fault codes. My indicators have never sense gone off since, which has made this problem quite annoying. Mainly because in the four subsequent times I have brought my Mazda 6 into the dealership, they state they cannot replicate the problem. I asked them to check the fault code history for the car but was told those are not stored in their system. They did state it sounded like a drive train issue and reset/reloaded the power train CPU. That did not fix the issue.
Since I canít seem to get them to experience the problem, I am at a loss of what to do next. I can only assume either a braking sensor is going bad or the CPU/Software that controls the brakes has a problem. Since this deals with the brakes I am fairly concerned. Any suggestions?