Sequoia Terminal Error

Hmm, intermittent electrical gremlins are never fun. I had a similar issue with my Sequoia - don't recall the exact year - and the 'Terminal 30' error sounds familiar. Did you check the charging system output? Is it within spec? Also, have you load tested the battery? A multimeter might show 12V, but it could still be dropping significantly under load. What about the circuit breakers, any sign of corrosion or damage? You wouldn't happen to have been messing with the starter motor recently, would you?

Thank you for your quick response! I haven't performed a load test on the battery yet, just a voltage check. I will definitely do that. Regarding the charging system, what would be considered within spec for a Sequoia? Also, where are the main circuit breakers located that I should inspect? I am by no means an expert, so any guidance you can provide would be greatly appreciated.

I'd have to check the exact voltage range for the charging system; consult the service manual for the precise figures – but you're looking for something around 13.5-14.5V with the engine running. The main circuit breaker box is usually under the hood, near the battery. Given that you are experiencing these symptoms, it sounds like you may have a battery issue or a short, which could be quite dangerous. I think you should go to the workshop. Don't mess with electricity if you are not sure of what you're doing.

Thank you for the advice! I took your advice and brought it to a trusted workshop. It turned out that the battery was heavily discharged, and indeed defective, which was causing the intermittent 'Terminal 30' error. They replaced the battery, and the starting issue is resolved! Total repair cost was 290€.