Astra Hybrid Undervoltage Error

I had a similar issue with my Astra, although it's not a hybrid. Symptoms sound very familiar. Have you checked the voltage regulator? A faulty regulator can cause the alternator to not charge the battery correctly, leading to low voltage issues. Also, what's the battery voltage reading when the car is off, and while it's running?

Thanks for the quick response! I haven't specifically checked the voltage regulator yet, but I did a quick test of the battery voltage. When off, it reads around 11.8V, and when running, it barely climbs above 12.5V. Does that align with what you experienced? Where is the voltage regulator located?

Yep, those voltage readings are definitely low. Mine were similar before I figured out the problem. Given those numbers, and the systems failing, it's almost certainly a charging issue and going to a workshop to check the alternator is a good option. You can try to locate the voltage regulator, but it is very complicated.

Okay, that’s what I was afraid of. Thanks so much for confirming my suspicions! I'll take it to a workshop to get the alternator and voltage regulator checked out. They found that the battery was heavily discharged and defective, eventually, the repair cost me 290€.