jaiCPA

After coming home from a 9 week europe trip I decided to try installing a new car battery on my 2016 is300 while extremely jet lagged. I stupidly installed the battery backwards and after connecting both terminals saw sparks and of course at that point realized i installed it on backwards.

After installing it correctly and attempting to start the car, I realized the car didn't detect my key and had to result to starting the car with the key directly on the ignition switch. The car started, however I am now showered my various system failure messages:
- Brake malfunction
- EPS failure, steering wheel harder to turn
- Check SRS airbag system
- Check ABS
- Check PCS System

The car seems to be in limp mode and automatically revs a bit by itself. I feel like I'll have to get the car towed to the dealership to get this resolved. But before I do that thought I'd check in with folks here to see what kind of damage I may of done to the car.... Pretty stupid careless mistake sigh

davyjordi

fuses and relays. check and replace them.

E46CT

I was going to suggest a main/big battery fuse but then i don't think the car would start. so the next thing i'd do is check all fuses to make sure one broken one isn't tripping all those. hopefully your main computer isn't fried or shorted causing the fault. hopefully someone has a specific answer for you here. i googled but didn't find anything 3IS specific.

also could the battery be faulty/shorted/discharged? check battery voltage as well. sometimes the batteries come from the store low voltage which would cause all the lights you describe. worth a shot...

sunamer

[QUOTE=jaiCPA;11371491]The car seems to be in limp mode and automatically revs a bit by itself[/QUOTE]

Probably because it detects a bunch of fuses are blown..
I am pretty sure lexus accounted for a possibility of mis-connecting the battery. Did you check the fuse box?