First post, hello all. I've been offered a c-max 1.8 duratec petrol which has a few issues. Messages 'brake light fault' and 'engine systems fault' when the car is started.

I've plugged an obd2 reader and originally had 3 codes, 2 of which I've sorted (dodgy coil connection and a broken cooling fan control wire)

The third started as:

P0571 - Cruise Control/Brake Switch 'A' Circuit Malfunction

So, I investigated the two switches on the brake pedal. I removed them both and checked them with a multimeter.

The top blue and white push to break switch was fine, the brake lights work ok.

The black lower push to make switch also worked ok.

I refitted both switches with the brake pedal in its home position and reconnected the battery.

Cleared fault codes and started the car, this time I get code:

P0703 Torque Converter Brake Switch B Circuit Malfunction

If I monitor PID 'brake pedal' on the code reader, I get a correct on/off reading when the pedal is pressed. This stops if i disconnect the wire to the black switch. So the switch and its wiring is ok?

So, any ideas... Am i doing something wrong refitting the black switch, is there a calibration procedure? Should I just change the switch anyway?

Another query, there's a whine from the throttle body when the ignition is on, I've recorded a video of the noise:https://www.youtube.com/watch?v=qnwgbyKgT70 Is this normal?

Thanks in Advance,

Matt