Hello all,

Here my trouble.
I have a brand new battery in the car and in the FOB.
From time to time the key is not detected. The car does not open or does not lock.
The stuff is that after some moment, 5 top 10 minutes, everyhting works fine, key is detected car starts in a second....


Some other times I found my car open...
This can happen anyware, at home, at office, also during a trip.

Last time I parked my car after a 15 minutes run and no way to lock the car, no way to restart the car, the key was not detected at all.
And again same thing, after 5 to 10 minutes, everything comes back to normal.

I suspect some ECU going wrong or some humidity inside the car...

Your help wanted !

Thanks,
Hervé

 

When the locking system does not react, did you try holding the key close to the start button? If so, does it do anything?

The anti-theft computer may be going bad, or there is a bad electrical connection. This is a complex circuit and if needed, a new computer would have to be programmed to the car with a dealer-level software. So the best thing to do is bringing it to a mechanic who has access to Toyota/Lexus repair and wiring diagrams or the dealership.

 

Open your key fob, remove the battery, clean the terminals with alcohol, lighty sand the contact tips, and slightly bend them with a small flat head to give more pressure against the battery. What happens is corrosion builds between the contacts and you get a spotty voltage.

Next time pay attention to the small led on the fob, it should light up everytime you press the button. When it doesnt light up then you have that voltage issue.

I had this happen to me, I replaced a battery within a months span. Thinking I had a dud battery, even though it was a panasonic. I always run top quality batteries, they just last longer.