Hey folks - this is my first forum! BUt I'm in a bit of a quandry about my 04 Tiburon with 64,000 miles and brand new BCM failure. I've been reading the threads and it seems this is a common and expensive problem that, for me, is affecting my driver's side turn signals. My main concern is what else this failure could possibly effect if not immediately fixed. My current dealership invoice also includes a bad thermostat that MUST be replaced in order for the car to run without overheating. any insight out there?

 

Since you are past 60K, your BCM is out of warranty. If you can buy a used one from a junkyard or eBay, I'd go that route first. Next would be to replace the relay in the BCM, third would be to pay the super-high price of a new one from the dealer.

See here for a DIY repair of the relay:
https://www.hyundaiforum.com/fb.asp?m=10848

If not fixed, the only real problem is the battery could drain from the light being left on when the car is turned off.

If the t-stat is bad, yes, you should change it. If it's stuck closed you will overheat. If it's stuck open you won't overheat but it will take a long time for the engine to warm up. That means slow heat and lower fuel economy.

 

great insight! Thanks. looked at the DIY - Yikes - guess I'll lit to the pros - but, oddly, my signals are stuck in the "off position" which the dealership says is odd - but I guess a better story for the battery! ANy other ideas or experiences out there, I'm glad to listen! thanks again!