My check engine light came on in my truck, so I decided to call around to see how much it would cost to get it checked out (some places do it for free- i.e. auto stores, except, as I was informed at AutoZone, no longer in the state of California). I had heard Aamco did it for free so I called not one, but TWO, Aamco stations to talk about an appointment and when I asked how much it would cost me to run the diagnostic, both told me it was free.
I took my car over to one, filled out all the paper work and had just handed over my keys when the guy tells me "the check is free with repairs" and I said, "Wait a minute, how much is it without repairs?" He proceeds to tell me that it is $40 if no repairs are done- NEITHER of the Aamco stations I talked to clarified that lovely little detail. I should have walked away right then, but I wanted to know what was wrong so I let them do it and ended up paying the $40 because I felt they were trying to rip me off when they said I needed a $400 repair.
That just gives you an idea of the type of establishment they are and what the employees are conditioned to say to customers.