First of all a big thanks to pakwheels for being a source of guidance for all these years. I have educated myself a lot.
I am in a fix at the moment and did not get any serious/satisfactory advice yet. Please help me with this. I am going to explain in as much detail as possible below. Thanks in advance.
Background
I am fairly new to cars and bought Prius 2007 1.5 in September 2016. The mileage on it was 65k when I bought it and now its 79k. Never had any problem before; except the voice of the motor (probably brake actuator) running for a couple of seconds when I press the brakes. This started a couple of months back.
Issue
8th July 17 - I was coming back from Nathiagali to Islamabad with family and mid-way (15KMs before murree) I parked the car for a while and when I restarted it, ABS, yellow exclamation in bracket (!) light, and handbrake lights turned on and there was no pressure that I usually felt when I pressed the brakes. When I drove (15-20KM/Hr speed) and pressed the brakes a loud noise (screetch) came as if I pressed the brakes in a very fast speed. I drove very slowly after that and reached Jheeka Galli and there was one mechanic there, he said I should change the brake pads. He changed the pads (i kept the old ones too) but still the lights were on and no pressure in the brakes. I reached Islamabad after a very worry-some drive.
9th July 17 - I took the car to Toyota Motors (aabpara) and on my way when I checked the brakes by pressing it at the speed of 15-20KMs, the same loud screetch it made. The toyota guys scanned the car and came up with C1342 error which read Malfunction in Hydraulic System(FL) and cleared the warning lights. There was another error in the software which the mechanic did not report to me and which I saw, it was C1241 Low Battery Positive Voltage or Abnormally High Battery Positive Voltage. When I asked him what it meant, he said it's fine, nothing to worry about. No other diagnosis was conducted on the car and he straight away suggested that I need a new ABS unit.
Later 9 July and 10 July - When I took the car out of the service station with the lights cleared, the pressure on the brakes was restored as if nothing happened. When I applied brakes as a test no screetch sound came out. I have been driving it and the brakes are working normal as before and the lights did not came back again. Only when I apply the brakes at higher speeds, a squeaky sound can be heard as if there is a friction in the break pads.
Help Required
1. Please guide me what could be the reasons of this episode? (brake actuator? fluid leakage? ABS sensors? or just the heat from driving down on the mountains? or whatelse)
2. Do you guys think I should change the ABS unit altogether? If yes, whether I get the new one or the used?
3. Is it safe to drive now or shall I park away the car until further work is done on it?
