High Voltage System Error

I own an S60 too, though not a hybrid, and had a comparable experience. A 'high-voltage system error' suggests it's linked to your car's hybrid battery system. A heavily discharged or defective high-voltage battery can cause those issues: error messages, engine shutdown, reduced power. Check the battery's state of charge and whether there are any parasitic drains impacting it. Inspect the electrical wiring and voltage sensors connecting the battery and motor for looseness or damage. It could be simply an electrical fault.

Thanks! When you mention parasitic drains, could you elaborate on where I should be looking? Are there specific areas known to cause issues in the S60, or common culprits I should prioritize?

Parasitic drains refer to components in your S60 that continue to draw power from the battery even when the car is off, like certain modules or lights left on. Given that you own a modern hybrid S60, it's more difficult to diagnose yourself. This usually requires advanced diagnostic tools to pinpoint the source. I recommend scheduling an appointment with a qualified workshop. They ran a comprehensive test and found that I had a faulty cable.

Appreciated for your help! I took it to the workshop as suggested. There was indeed an electrical fault, a defective cable on the high-voltage system. The total repair cost was 290€, but the error message disappeared and the car runs smoothly now.