Lexus GX Hybrid Intermittent Starting Issue

I own a GX too, though not a hybrid. I once had a similar issue. The problem turned out to be a heavily discharged battery. Have you checked the voltage when the engine is off?

I did check the voltage, and it seemed a bit low, but nothing alarming. Could a slightly discharged battery really cause such an intermittent issue with Terminal 30? I would assume that the battery would be ok after a long drive.

Think of it like a leaky faucet – a small voltage drop can disrupt the entire electrical system. Given the symptoms and your voltage reading, I'd suggest having the battery professionally tested, as well as the continuous plus. It may be time for a replacement or you might have a short somewhere.

Took it to a workshop, and you were spot on – the battery was defective and discharged. They replaced it for 290€, and it starts like a charm now!