Reprogramming an 05 Sonata Computer
 

Hey all, I have an 05 Sonata 4 cylinder automatic. I was looking at reprogramming the computer so I downloaded the J2534 HMA program from the hmaservice.com site. I have the OBD2 hookup and I was just wondering if anyone has done something like this before. Let me know.

Explain the J2534... what is it you trying to accomplish ?

We use Hi-Scan and GDS to program the modules with Hyundai updates.. not somethng that going to happen with just a PC alone.

This is how we do programs, PC, USB cable to Vehicle Communication Interface module ($1800+), and then plug into car with OBD-II connector

https://www.hyundaiforum.com/forum/a...1&d=1287506112

https://www.hyundaiforum.com/forum/a...1&d=1287506112

Well that actually answers that question and why I can't find updates for the Computer. Oh well. I guess I'll have to take it to the shop. I was hoping to get better fuel effciency, horsepower, and maybe fix my speedometer, it's off by 10%. I measured it with my GPS and a Friends GPS

You really think a simple computer programming is going to get you better mileage and power? If it were that easy, Hyundai would already have done it. Why would Hyundai tune the computer to get less than the maximum mileage and horsepower?

i'll take a shot at trying to answering that.

I saw a sign once that said;
quality, speed or quantity - you can only choose to improve 2!

in this case, it's; horse power, gas mileage or engine durability.
Hyundai has balanced the 3 as they see fit (and give us a 10 yr 100,000 waranty).

by making your own changes; you can increase horse power and gas mileage but lose engine life. (and void your warranty)

how much engine life will you lose? who knows. well taken care of, a sonata could easily go 200,000+ miles. are you going to drive it that long? if no, then maybe tweaking the module and losing some that engine life is worth it.

actually most performance upgrades mostly make changes to sloppy transmission shift control and timing increments which can extend trans life but more harsh to drive

What I was thinking was to just tweak it a bit. The car is out of warrenty (121000 KM on her). I'm not too worried about a rough ride, what I was hoping for was even just a little improvement on overall power or gas milage if possible (prefer milage given the cost of gas right now).

Thanks for all the answers guys!!!