I recently ran into an issue with my 2014 IS350 RWD Base, the car was running just fine with no problems at all, the day the problem I was able to drive from home to the gym and then to work. When I was leaving work, I tried to start the car and noticed the brake was stiff and would not depress, the car did not crank when trying to turn it on, all electronics turn on as well as the headlights. I eventually started to self diagnose the car, found that all the fuses and relays are fine, battery is at 12v so I don't think the alternator, I started to assume that it would be the starter but currently the vehicle is at my friends mechanic shop and was informed that starter tested good too. Has anyone ever experienced this problem before and found a solution??

 

If the brake pedal was stiff as you described, then that's a battery drain. If you didn't left any bulbs open, something is draining your battery - I will start here.

This happens to me all the time (2 dash cams with parking mode on) if I don't use my car for 2 days. I make sure I always have a fully charged battery pack jump starter in my trunk.

 

I took the battery to Oriellys and the battery tested good and they told be that it was not near EOL, so I don' think the battery is the issue especially since all electronics power on such as the Dash, Nav., Radio, etc.

 

All of the dash lights and radio may function, that doesn't mean your battery on that moment had enough juice to start your car.

Consider having one of this. It can jumpstart your car 3 to 4 times before you will need to recharge.

 

The issue you are having is the battery.
If it is the original battery, then it's time to replace it.

I know you said the battery tested fine...doesn't matter, the issue is still the battery.
Likely a cell has gone bad, which can give you a false positive on most battery test machines.

 

I just got a call from the shop where the car is currently at, and they informed me that the main fuse in the fuse box near the battery was blown, and was also told that the fuse box will need to be replaced. Is this a known issue with these models?

 

That's definitely not a common issue at all...you would be the first and likely last.
And why does the entire fuse box need to be replaced?
If the main fuse was blown then how is it that all the electronics were working...including the headlights??
Something doesn't seem right here at all...what you described vs what they are telling you doesn't jive.
And a main fuse has very high amperage, so it's not easy to blow at all...you literally have to boost the car with the terminals backwards for a main fuse to blow.
This doesn't explain how you drove it to work and the gym and then all of a sudden it wouldn't start.
Hey...they have the car in person so these are only my observations from the other side of a monitor...but for sure I'd bet the farm that either we're missing a critical piece of information (like a rodent was chewing on something) or something is seriously not right with what they are saying.

 

Main fuse was blown? Is there such a thing like a main fuse? I'll probably need to look for this. So a fuse that handles all the fuses? hmmmm sounds off to me.

Maybe they meant ignition fuse?

Anyway, this is possible in a circuitry which means the previous owner (if you bought it used) or whoever worked on the fuse box replaced a blown fuse (or fuses) with higher amperage than the original, thus overload is imminent.

 

UPDATE: They were able to get the car started and found that a loose cable was causing the issue which the say could have blown the fuse. But after getting the car started they saw that the check engine light was and said that they also saw the TCS and ABS were on, which were the reasons for the check engine, they think its because of the fuse. They're looking deeper into today. I'm just glad the car is running now! I'll keep you updated

 

It is always appreciated when people provide updates so you are winning brownie points in my book

 

If the Check Engine light is on they need to diagnose that first as that is what is causing the ABS/TRAC/VSC lights to come on.
Those systems have sympathetic codes that trigger when certain (most) Check Engine light codes are set. Once the engine code is rectified, those other warning lights will clear on their own.
Hopefully they figure this out before the repair bill gets out of hand.
I would be curious to know which fuse blew exactly and what wire was lose. Unless someone was in there previously working on something else, what they are proposing in terms of a lose wire seems a little unlikely.

 

I certainly hope they didn't shorted out the main fuse terminals temporarily just do a test. The sudden issue with the wiring is very uncommon, unless otherwise there was a living thing under the hood that ate it up causing a wiring short circuit.

 

I'm glad you said it and not I lol
I get the feeling they may not be familiar with Toyota/Lexus products.

 

UPDATE: so it turns out there was just a wiring issue that may have been caused by the previous owner, everything has been resolved and the car is ready for pick up! So glad I can finally drive my car again

 

I know this is 4 years later but.....do you know which wire was loose and any speculation why?