Beware, I just got scammed by a Lexus Dealer on my LS430 2005. My car seemed like it was braking oddly below 10 mph. I took it to my buddies shop and ran full system scan which only turned up a pending transmission code which recommended a flush as a fix but nothing severe. I saw the front brakes were getting low so I replaced the rotors and pads. It didn't solve the problem. I decided that the Dealer might have some insight into this. The day I was to take it there a check engine code showed up on the dash. I dropped it off anyway to get them to see if it was the anti lock braking system or speed sensor acting up. Well during my busy day the service advisor calls me and says they need to spend some extra time diagnosing this issue. I approved and extra hour. I don't hear from them for the rest of the day until after 5 when they try to hit me with a bill of over 2k to fix the TCM. They told me they were positive this would fix the problem. I started looking on the web for information on this TCM. I find out that all of this is contained in the ECU Engine control module for the car and is a common problem. The fix will run under $150 including shipping if you send your ECU to SAI. I went back to the dealership to get my car and they hand me a bill for $384 for scanning and diagnostics which was already clearly visible from the first moment I brought the car in. I am willing to pay a diagnostic fee. They had to know this was a common issue and exactly what the fix was from the moment they saw the car. I will never trust them with my car again.

 

@Mobile1 , I am sorry to hear of your experience. It is unfortunate that the dealer made this first impression. Don't fly out and strangle me, but I don't think you got scammed. Over-charged? Of course, but not scammed, maybe. There has been a lot of discussion on other threads about dealerships, and several of us have run into the comment from dealerships, "We don't repair, only replace." They are just not that shop. An independent mechanic is more likely to repair. Yes, the chip thing sent to SIA (not SAI) is discussed in several threads here, and I may use it too one day. As for the bill, $384 sounds like 2 hours to me, which you state you ok'd the 2nd hour.
Should they have known it was doing that? Yes, seems hard to believe a lot porter did not feel it and report it, but maybe they didn't. Lot porters are often very young people and don't give a crap.
Did the mechanics know about how the chip fix? You have no way to know, and it is not their business to know. They have a book. The book says this, and here is how long it takes.
I think you have to take your lumps here. You could try to argue for 1 of the hours back. I do not think you got directly scammed here, but the dealership may have been negligent.
Anyway, I am sorry to hear it. A dealership can be a good ally at times, but the "repair, not replace" thing is important to know going forward. I got the same thing recently with my fritzing nav screen, and there are a couple of threads about that.

 

Taking our cars to a dealership for anything is not recommended. They are not positioned to work on cars old as these and their rates are outrageous. Finding a credible and reliable independent takes a lot of effort and research but is the best option (unless you are a skilled DIYer).

The OP story is typical and repeated often in these threads.

 

^^^^^^^ This so much. My mechanic is worth his weight in gold he's saved me so much money on my cars vs. the dealership over the years.

 

I agree with CA2WALS430 about dealers (and most mechanics for that matter) just replacing things, not repairing things. My two favorite examples are starters and alternators, both of which can fail and be quite costly to replace, but can be repaired at low cost (typically $ 50 or so for the parts that wear out, plus your time to R/R). There are excellent write-ups and how-to videos. Or starter/alternator shops will do this repair and you will get essentially a like new unit for a small fraction of the cost of an OEM unit.
Alternator rebuild:
https://www.clublexus.com/forums/ls-3rd-gen-2001-2006/899113-diy-alternator-rebuild.html

Denso starter rebuild

 

You would be right if the check engine code didn't directly indicate there was a transmission issue. I went to a buddy's shop and used his snap on scan tool which reads all systems on most cars and did a all system check on this one. The only thing it found was a pending code on the transmission. It recommended a trans flush as a remedy. When I called Lexus about the car which had no check engine light yet I asked about getting a trans flush which they said they would not do. I thought it might have been a bad speed sensor issue like I had in a Saab one time so I thought the factory machines might work a bit better and I would get a honest read from them. Everywhere I check on the LS430 and transmission it tells me exactly the condition that my car was experiencing. These are professionals and they didn't know this common problem. Highly unlikely or totally incompetent. Either way I will never use them again.

 

Here is where a reliable independent comes into play. Preemptively I had my LS430 transmission fluid flushed and refilled. Takes up to 17 quarts of fairly expensive transmission fluid when done right (any amount substantially less than that indicates they did not do a full flush/refill).

I noticed immediately better transmission performance after this was done.

Hope you get your issue resolved.