The car wouldn't start this morning. But I was able to open the door with the remote control and turn on the power, but there wasn't any display or radio. I got a jump from my neighbor and the car was working OK. But later on the remote wouldn't open the door again the horn was making a short soft honk every few seconds. I saw that the horn relay in the engine fuse box was blinking a green light and pulled it. I got another jump for my car. But then it quit again later on not too long after it was jumped. The horn was honking and the relay was blinking again, so I pulled it. The car went dead yet another time. I just remembered that a few weeks ago I left the car power on for 3 hours. I wondered if that was causing all the problems. I hope it’s only the 12 volt battery and not something major. What do you think? Do you have any ideas?
Hey there, thanks for writing in about your 2010 Lexus HS250h. Your problem is most likely the power integration relay/module (what you’re referring to as the horn relay). The component is used to supply power to the horns, keyless entry system and all kinds of other stuff. It can also prevent the vehicle from starting if it is drawing energy from the rest of the system. I suggest having a professional, such as one from YourMechanic, test the cause of the no start and replace the horn relay if necessary.
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