The SVS warning literally means Service Vehicle Soon. It suggests that the on-board computer has detected something wrong with the vehicle, and is warning you that it needs attention pronto.

The fact that it’s losing power is probably evidence of the computer placing it in limp home mode to prevent it doing any further damage to whatever mechanical system is causing the problem in the first place. Take it straight to a workshop and have the vehicle scanned to see what the fault might be.

First thing: Don’t drive this vehicle anywhere. Any time you need to pump the brakes to get a vehicle to stop, you have a major safety issue. Because the time taken to give the brakes that extra pump might just be the difference between stopping safely and running into something or someone.

A workshop should be able to sort this, starting with what’s called bleeding the brakes. Over time, the braking system can ingest air which – unlike brake fluid – is compressible and can make the pedal feel spongy or require the pedal to be pumped before much happens. The bleeding process removes this air, leaving only brake fluid in the system.

But you should also check the condition of the brake fluid as it should be changed periodically. There’s also the question of how the air entered the braking system in the first place, so you may need to replace some seals to prevent it happening again. Either way, the car is not safe to drive as it is, and should be towed to where ever it’s going to be fixed.