Why does warranty work require you to approve estimate?

[Biscuitman]

Taking my car in tomorrow to have them diagnose another suspension rattle issue and they asked me to approve the $260.00 repair cost, even though the car is still under warranty. Why do they structure their billing this way?
Never seen this with other brands I have owned when clearly doing warranty issues.

 

[Tam]

Taking my car in tomorrow to have them diagnose another suspension rattle issue and they asked me to approve the $260.00 repair cost, even though the car is still under warranty. Why do they structure their billing this way?
Never seen this with other brands I have owned when clearly doing warranty issues.

Because if they found nothing wrong then you are stuck with the diagnosis fee.