Hello guys first post here, I used to be active on bimmerforums and mbforums but I recently made the transition to an Ultra White/Rioja IS300 F-sport. I love the car, but I NEED the is350 tune or better. Money is not an issue, where can I get this done. Before anyone says I should have gotten a 350 instead, the dealers in my area did not have the one I wanted at the price I wanted. Where can I get the tune!!

 

Well if your after just a 350 tune then the easiest would be to buy an ecu from a scrapyard and swap it in.

The only person on here that has found someone who can actually modify the ecu is Mesh074. And he's in the Middle East.

 

Sounds like money is/was an issue

I don't think its a straight swap.

 

^^^ correct the ECU is programmed to the engine, it's not plug and play

would've been cheaper to get the 350 in the first place.

 

What do you mean it is programmed to the engine? The engines and ECU's are all mass produced. You should have no trouble what so ever taking an IS350 ECU from the same generation and putting it into another IS350 of the same generation, and if it is true that the IS300 is just a 'detuned' IS350 then the harness should plug right in and away you go. The ONLY thing that would show different is when you connect a code reader, the VIN number would be wrong, but that doesnt make any difference for how it runs the engine.

 

It's not just the VIN, each modern ECU has security measures in place called immobilizers (knowing Lexus and their uncrackable ECU, this is almost guaranteed) that won't let allow the car to run without its original key, at minimum. There might be other hardware that provide additional layers of security that prevents you from using any ECU that wasn't the original. Although they are massed produced, each ECU is paired uniquely to the car (same concept as alarms, even though its mass produced, you can't just use the alarm fob on another car and expect it to work without reprogramming).

 

Correct me if I am wrong, but is there not a seperate computer responsible for the immobilizer functions.. Usually it is referred to as a BCM (Body Control Module).. The ECU would get a signal from the BCM to start and run the engine.. Typically BCM's handle windows/doors, HVAC, radio, and lighting in some cases..

I have yet to see a wiring diagram for the whole car.. Is there any Lexus techs around that can confirm whether it is possible to just swap an ECU?

 

Sorry. I mean to say I'm willing to spend a couple thousand. I got a killer deal on the 300 and the same 350 with awd was almost 5-6k more. I wasn't willing to shop around. In hindsight I really wish I had just gone for the 350. When the salesman told me that the engine was the same I just figured I would tune it. Mistake on my part lol


To everyone else, thanks for the input. Looks like I'll just have to be content with what I have. I'll probably end up doing an exhaust and intake and call it a day. Hopefully a tune comes out soon!

 

The ECM contains the immobilizer codes

You would have to get a Lexus dealer to program the ECU to the car.

Still on the fence about purchasing a 2016 IS350 ECU just to see if this would work.

 

I don't think lexus would be willing to reprogram a 350 ecu to 300 just because they don't want to encourage people from buying the 300 and spending way less to convert to 350, It made no sense for lexus to introduce the 300.

 

This. My theory on the only reason the 300 exists is because Lexus couldn't get the 200t paired with their AWD system reliably in time for launch. I can only hope that it's because they're putting resources into developing a successor to the 350 engine.

 

how accurate is the info that the only difference between the engine of a 350 and 300 is in the ECU tune? Perhaps the cams, throttle body, intake, and other non ecu components are different? I see that the engine displacement sizes are exactly the same.....

 

Oh really? And how about the fact that ECU controls fuel injection and IS350 has extra injectors comparing to IS300?
So you really think you would put an ECU from an IS350 into an IS300 whose engine is physically different (at least the fuel injection part) and
somehow you would get IS350 performance, just like that?? It isn't even entirely clear such contraption would even produce a workable engine.
I had no clue I would read something like that on Lexus forum.

 

haha thats 1/2 the posts on this forum.

 

Where did you get info that the Is300 had less injectors. This is the first I heard of it. Very interesting!