HELP car won’t start after ecu rebuild

yukinon · January 25, 2023

Not sure if this is the place to ask for help, but delete if not allowed.

I just got my ECU back for the second time from Relentless motorsports, it did this before and he told me he put the wrong caps in them and I sent it back. He got me a new ECU and went over that one too, I was told that he removed the stock immobilizer in the ECU, i'm not sure if this is maybe causing an issue? Car won't crank at all and there's a loud constant beep that doesn't stop, none of the main lights illuminate on the cluster, not even the CEL appears. (the lights did work before I got my ECU rebuilt) only thing that happens when I try and start it is the climate control lights turn off and on, but the lights on the dash stay on and don't turn off at all. Also the security light doesn't blink at all, my key fob still works, i'm able to unlock/lock my doors and trunk. I told him about it and he basically told me to kick rocks, he said i have other issues as it's a totally different ECU.

It's just confusing because my car never did this before, everything started fine and i never had this beeping noise. The reason I sent my ECU out to get rebuilt by him is because my car wouldn't start one day after work. I tried to jump the battery and it still didn't start. I got a new battery and the car started right up. Next day it just started making a horrible noise. The noise did go away but it now it sounded like the car was knocking(might've just been a loud valve tick is what someone told me) i drove around the and I wouldn't hear the ticking once driving. Then the car just fell on its face, CEL came on, the car felt sluggish. In the panicked state I was in, I parked the car and shut it off right away. I didn't scan the codes at all, I email RMS about it and he said it was a bad ECU, so I sent it out and this is where I am now. I was told it was maybe the harmonic balancer that was causing the horrible noise.

Has anyone ever experienced this before? My car started fine before and this has never happened, I'm just lost on what it could be, it's been sitting for almost three months, battery was replaced before and was stored inside my house while waiting for the ECU. I checked the fuses and none of them looked blown, any help is appreciated, I have zero idea what is wrong with my car now and it sucks! If there’s anything you want to know just let me know. I do plan on ordering some of the main fuses in the engine bay, none of them looked blown through the clear cover but i don’t know if that’s an indicator to know if they’re blown.

[https://youtube.com/shorts/llL8\_J7mzhg?feature=share](https://youtube.com/shorts/llL8_J7mzhg?feature=share) loud beeping noise after getting ECU rebuilt and replaced.

[https://youtube.com/shorts/tOhO6Cm1st0?feature=share](https://youtube.com/shorts/tOhO6Cm1st0?feature=share) horrible noise and loud valve tick? This was before I sent my ECU to get rebuilt.