Braking malfunction

What is your question?

After about 100 miles all the dash lites came on,cel,anti skid parking brake ECT. It said pull over right away and have towed to dealer. Well I was not to far from home so drove it home. The brake pedal was very hard to push so I drove slow and tried not to use brake pedal. I could use it if I did it gently. Next morning , drove it to shop and they called me back and said they got a code c1247 which was brake pedal stroke sensor. Replaced that and had it calibrated. After driving around 70 miles it did the same thing. Stiff brake ,lites on dash, so took it back and it came back with the same code so they erased the code on the obd and it drives perfect until I hit the 70 mi and does it again. This has happened like 5times and even took it to different shops. All they do is reset code and they tell me it is good to go .Could it be in the brake booster? When I tell them the problem is still there they all have said " it's probably the abs module but they are just guessing. Booster?

What makes this problem better or worse?

When the dash lites are off it rides perfect for 70 miles or so

How long has your 2008 Lexus LS460 had this problem?

More than a month