So i just encountered my first ever RX problem. I was driving the car around yesterday and it was fine. When i went to go start it later that evening it wouldn't crank and all of the dash lights were either trying to come on or blinking in and out. Seemed like a battery issue. I pulled around one of my other cars and tried to jump start it. Once my battery was plugged into my other toyota, all of the dash lights, navi, radio, etc came on perfectly.... but when i try to start it, all i get is a 2 cranks and then deeeeaaadd.
I tried leaving the battery on jumper cables for about 5 minutes but still the same results

Could it be my alternator? Maybe a more serious issue? Any ideas?

All this on the eve of getting my is350....

 

im guessing its just a very weak battery, possibly left a light on or something. It happens once in a blue moon. Just get a new battery then test the alternator with the new battery to ensure its charging properly so you save yourself another battery.

 

That is a possibility but i think it might be something more than the battery now. I realized i was using my old jumper cables last night. I just hooked up my working cables and the car turned right on. The navigation screen showed some japanese writing and "system is updating" screen. I let it idle for a few minutes then took it for a drive...

So everything seemed until it tried upshifting from 1-2 and then 2-3. I felt a bit of a jerk everytime. Kind of odd. Also, at one point the navigation screen and audio rebooted it self.

To top it off, once i got home i turned it off and tried starting it again...
it was dead again.

sigh

 

Battery could have an internal problem, but it sounds more like a battery terminal issue since jumper cables (wiggling around the terminal) seems to provide a temporary fix. Try removing, wire brushing and cleaning the terminals and cables, then reinstalling them. Somewhere in there you have a high-resistance or intermittent connection.

Transmission and radio/nav issues are probably caused by total loss of battery power wiping the memory.

 

Thank you!!

turns out it was the battery

I had a spare battery that i placed in the rx and everything is perfect now. Its an interstate battery that is a little smaller than the one that was previously in there. I will probably have to get a new one but atleast im up and running. Thank you all!!

 

I was going to say battery, thats about the only common thing that can stop a Lexus from starting in my experience.

 

Go to Costco and get a battery, they work great, just dont get a Kragens battery....

 

Costco batteries are made by Johnson Controls. They have 3 years full replacement. Great price, too. $5 core charge.