CR Z Electrical Overvoltage

Sounds like a headache. Overvoltage errors often point to a charging issue. While a weak battery CAN trigger such faults, it's less likely to directly cause overvoltage. More often, it’s the voltage regulator malfunctioning and allowing too much voltage into the system. Have you checked the output voltage of the alternator/generator while the engine is running? A faulty voltage regulator can fry sensitive electronics quickly and explain a weak battery, as it's constantly being overcharged or drained. Do you have experience with a multimeter?

Thank you for your insights! I have a multimeter and some experience using it. Could you elaborate on where I should measure the voltage, and what would be considered an acceptable range for my CR-Z's hybrid system? Also, if the voltage regulator is the problem, is it typically a separate component that can be replaced independently, or is it integrated into the alternator/generator unit itself?

Okay, good you have a multimeter. Connect it to the battery terminals while the engine is running. You're looking for a voltage between 13.5 and 14.5 volts. Anything significantly higher consistently points to the regulator. As for your CR-Z, I'm not intimately familiar with that hybrid setup, but voltage regulators are often integrated. Given all those fault codes and electrical malfunctions, I'd advise against too much DIY and suggest taking it to a workshop with hybrid experience, to avoid further damage to the ECU or other components. They can properly diagnose the issue and ensure proper circuit protection is in place during repairs.

Understood. Thank you so much for the advice! Based on what you've said, I'll definitely take it to a trusted mechanic for a thorough diagnosis. It turned out the cause was a defective car battery which caused all kind of issues with the electric circuit, and it cost me about 290€ to get it repaired. I appreciate you steering me away from potentially making things worse myself.