Menlo EV: Overvoltage Codes & Electrical System Failures

Had the same power surge symptoms on my 2019 Chevy Bolt EV (similar electrical architecture to your Menlo). After some basic troubleshooting, noticed multiple systems going haywire and getting unusual fault codes. Being somewhat experienced with EV electrical systems, I first thought it was just a discharged 12V battery. But the workshop found the voltage regulator was actually the culprit, causing erratic power distribution and those overvoltage codes you mentioned. Total repair was around 290 for parts and labor, they replaced both the voltage regulator and the weakened car battery since they were interrelated issues. What's your exact battery voltage reading on startup? Also, which specific systems are failing? This info would help determine if you're facing the same issue. Would definitely recommend getting it checked soon, electrical issues in EVs can cascade into bigger problems if left unchecked.

Thanks for the detailed response about the voltage regulator. My startup voltage is pretty inconsistent, ranging between 10.8V-11.2V across multiple cold starts. The main systems affected are the infotainment unit cutting out out of nowhere and climate control going unresponsive. Sometimes the power windows act up too. I've hit 131330 KM and just had my annual service last month, but they didn't catch these electrical issues during inspection. The high voltage systems seem okay, but these circuit protection problems with the 12V system are getting worse. Definitely sounds similar to what you experienced, I'll have them check the voltage regulator specifically when I take it in. Did you notice any warning lights before your voltage regulator completely failed? Just trying to gauge how urgent this is.

Ah yes, those voltage readings are nearly identical to what I experienced before my voltage regulator failed completely. My car ECU started throwing those same overvoltage warnings when the readings dropped below 11V. The warning lights were pretty inconsistent, sometimes the battery light would flicker, other times the check engine light would out of nowhere pop on and off. The alternator failure symptoms you're describing with the infotainment and climate control match my experience exactly. These systems are super sensitive to voltage fluctuations. My power windows also started acting weird, that's actually what convinced me to get it checked immediately rather than wait. After hitting 130000 KM, these circuit protection issues became more frequent. The workshop mentioned that the voltage regulator failure had been gradually weakening my car battery. When they tested it, the battery could barely hold 80% of its rated capacity. Don't wait too long on this, I pushed it for about 2 weeks after noticing the symptoms, and one morning the car just wouldn't start at all. The failing voltage regulator had completely drained the 12V battery overnight. The high voltage systems stayed protected, but the regular 12V circuits were a mess.

Those symptoms line up exactly with what I'm seeing. The voltage readings being that low definitely has me concerned, especially since I'm right around the same mileage where your regulator failed. The car electronics are getting more erratic by the day, yesterday the infotainment system rebooted three times during a single drive. Given how the symptoms match and the overvoltage codes keep appearing, I'll schedule a workshop visit for next week to have them check the voltage regulator and do a full electrical system diagnostic. Don't want to risk being stranded with a dead battery or cause more damage to other circuits from power surges. Really appreciate you sharing your experience with the electrical issues. Having a real example of the same problem and fix helps narrow down what to tell the technicians to look for. Will make sure they test both the voltage regulator and the 12V battery condition since they seem connected. Makes sense why these circuit protection problems weren't caught during the regular service, they probably didn't do extensive electrical testing since everything was working fine that day. Just glad I asked here before the issues got worse.