Lexus Troubleshooting Questions? Ask a Lexus Expert
I am sorry that you have not been helped yet. I just came online and saw your question.
By the symptoms, I suspect that the keyless entry control module has failed, but I need to get the vin number to pull the schematics to see if there is anything else that would cause it
If the car battery either has at least one dead cell or completely dead, it could cause it, but normally you would have notice some symptoms of a weak battery such as dim lights, slow starting, power windows working very slowly, battery light on. Unless the car has been sitting for awhile unused, then you would not have noticed any symptoms.
If it is the keyless control module, the only option is to replace it. I am going to pull the schematics now and go thru them. Give me about 15 minutes.
If you have a voltmeter handy, check the voltage on the car battery. If under 10v, replace it. If 10v to 11.5v, have it charged. If 11.5v or higher, then it has enough power to start the vehicle
Ok, then we do need to check the battery. If you dont have a voltmeter, then you can take the battery out and take to any parts store and they will test if for free and if needed, they can charge it overnight for you if you dont have a battery charger