[Sapote]

I don’t hear a buzzing sound when I put my ear to the sensor

Where is this sensor?

I got the car manual swapped and my ECU was recoded, so i’m not sure where to start or what to look for.

Do you mean the issue happened after SMG conversion?

 

[Sapote]

The 4 sensors located on my rear bumper, other forums say I should hear a light buzzing whining sound from these sensors when the car is in R.

They’re ultrasonic echo distance transceiver, works like a bat.