Hi there (first post)

I have a 2002 3.0 v6 AWD. It's a UK car. Yesterday I noticed I was getting about half the braking power and pedal was pulsating. This was a gentle brake. It happened 5 or 6 times in a 2hr journey. The rest of the braking on the journey was 100%. Engine management light came on after the first incident and stayed on.

I don't have a code reader and little money in the bank (been out of work all through COVID). I am mechanically minded and I know it's not the brake discs (rotors) or the brake pads or anything to do with the wheels/tyres. It also doesn't appear to be vacuum or servo related, or master brake cylinder related. It's definitely a brake system issue. All of the braking was gentle. I am wondering if there is some kind of brake valve in the pipe circuit that is faulty?

The firmness of the brake pedal isn't affected when it happens.

Hoping you guys can point me in the right direction for some further research.....

Many thanks!! Bob

Edit: I should also mention there's no ABS warning light