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Comments
I didn't do that but other guys did. It was a great prank especially if the muffler survived with no damage
The truck I'm mentioning wasn't an ignition off prank, the truck did this trick all on it's own because of a secondary air system fault. It would have been a classic though had it been on purpose!
Does that mean those in the truck did NOT expect this backfire waking up the whole neighborhood? If so, it was even funnier.
2014 Malibu 2LT, 2015 Cruze 2LT,
Some cars were much better (louder) than others and some mufflers put up with dozens of backfires without blowing up.
Other cars didn't fare as well. We taught the trick to one classmate who, in his first attempt to scare the hell out of a bunch of us standing in front of the high school managed to blow the entire exhaust system off his dad's elderly Buick.
Another kid tried in vain to get his VW beetle to backfire without success until he finally blew off one of those chrome tailpipes.
Todays cars just aren't as much fun...probably a good thing!
Yep.
If so, it was even funnier
Not to them.....
Those had a heavy iron "blast furnace" of sorts as part of the emission systems. Gas would sometimes slowly drip into that furnace AFTER the cars were parked. Some guy might park one in his garage and be un his house eating dinner when it went off! Talk about LOUD!
When I was in the tool business I was once inside a shop that had one up on a hoist. There was a guy under it changing te oil or something when it went off.
It made an M-80 sound like a cap pistol! The guy under the car didn't stop running for a half block. People screamed and we all ran for cover at first not knowing what it was! When I looked up I saw it was an early rotary and I started laughing. I have to admit, it scared the bejeesus out of me.
No doubt payback for my misspent youth scaring people doing the same thing.
Army trucks were pretty loud too especially in that one way tunnel that leads to Ft. Chronkhite right after the Golden Gate Bridge.
I have personal experience on that one!
My stall was right across from the desk and I had a Chevrolet Caprice in for it cutting out on the highway. As I was checking it over I realized that if I snapped the throttle it would occasionally cut out right in the bay. That was great because it meant I could test and prove where the failure was coming from. So watching my tools I snapped the throttle, and it revved up normally. I did it again and it revved up normally. The third time it started to wind up and it cut out, I saw that I had lost spark but I didn't lose power to the coil. Well it turns out I didn't lose fuel as was proven by the back fire it produced when it lit back up.
It took the dust off of the rafters in the building.
I did feel kinda bad for the two old ladies that were at the service desk, right behind the car. The service manager said they both about jumped the desk into the trailer with him.........
The diagnostics were straight forward, #1 cylinder wasn't firing. It was easy to confirm that the cylinder had spark with the secondary coil on plug lead for the PICO scope. The next check was for injector pulse and the injector wasn't triggering. Connecting the scope, there was power to it, but the PCM wasn't grounding it. A quick glance around the engines wiring harness revealed a wire that didn't belong under the hood. Sure enough it was a poor splice for a remote start system that needed to see the injector pulse to know if the engine was running or not. Repairing the damage to the wire caused by the way the remote start was attached to it restored the injector's operation.
When we called the customer to report what we had found and that the car was ready to go, the owner voiced both surprise and pleasure. For us we solve issues similar to this all of the time and we really try to always have a straight in at the problem and straight back out approach. Customers like him make what we do worth the effort.
Fooled? No, not this time. But no matter what a noid light shows you, you're not done yet, and that's just one of the problems with that approach. The light would not have flashed with this failure. But was the problem no power to the injector, or a loss of injector command? Was the loss of injector command a wiring issue, or was the computer not commanding the injector to trigger? Was the computer not commanding the injector because it has failed, or because it has intentionally turned the injector off because of a misfire detection?
Noid lights trick techs (people) when they make it look like an injector trigger command is present but the circuit has actually failed sufficiently that it cannot carry the current required to open the injector. In those cases the noid shows a pulse when in reality you don't have an injector command pulse. A stethoscope is a much better tool to determine if an injector is triggering or not as long as it's possible to reach the injector. But even it still doesn't tell you why but at least you didn't disturb the harness and have risked temporarily restoring the circuit. Today especially with gasoline direct injection you cannot always reach the injectors easily, nor is it safe to try and test them with traditional routines anyway.
By taking the right approach the first time, a tech actually spends less time locating the problem and never get's tricked into believing that the circuit is functional when it really isn't. Noid lights are/were notorious for setting that trap and have caused many a misdiagnosis.
The extra wire for the remote start system was obvious to me, but it was shielded with corrugated wrap just like the rest of the harness and was routed rather nicely so if you weren't real familiar with what the vehicles harness should look like it might not get your attention. With the schematic in hand and the scope already connected, we can use the scan tool set to command the injector to be triggered via the ASM tests. This way all of the checks are done at a high level of safety, and that means without the engine running.
A solid diagnostic approach is one that doesn't have to be changed by a vehicle's characteristics. This injector and it's circuit just happened to be easy to reach. A few weeks ago the #2 injector on a Ford Escape was proven to have failed mechanically without having to remove the intake manifold first. Both failures are diagnosed with the same fundamental, repeatable routine.
BTW, Remember why I visited here, NBC's "sting" operation? If I was going to rig a car to test someone's ability to diagnose, I would easily set a trap where diagnostics done with a noid light would fail and people would be condemning injectors and computers falsely. That wouldn't happen with the right approach, and it really doesn't take any longer.
Maybe we could arrange for Oprah to break down in her old Pontiac G6 near your shop for a segment.
Oprah could add the shop to her show of favorites. Some people seem to live and die vicariously on what she has on that show. The repair shop would be overrun with women wanting their car repaired at Oprah's Favorite Shop.
2014 Malibu 2LT, 2015 Cruze 2LT,
Since when is anyone interested in hard work, done correctly, while doing everything possible to try avoid getting involved in a train wreck?
Reality shows live by the train wrecks, and even when it comes to doing a live radio show the only thing it really does is attract the nightmares, "the ones nobody else can fix". The publics perception of what we are supposed to do day in and day out doesn't allow us to charge correctly for the time that they eat up. So in the end it doesn't matter if we are the last stop for many problems like that, we can't be profitable and stay in business fixing them.
One more rotary story...
Years ago, I guy I knew bought a well used but nice (and FAST!) Mazda rotary pickup truck. The person who sold it to him said nothing about it ever backfiring.
Well, this guy lived in a very upscale apartment building that had underground parking. For the first few days his new truck behaved itself. Then one night after working the night shift, my buddy pulled into his stall at about 2AM and went straight to bed.
About ten minutes later, this tremendous explosion shook the building!
He heard curses and screams and running feet. He looked out his window...nothing.
About three or four nights later the same thing happened! People were very upset and they all figured someone was going by and tossing a M-80 or simlar devise into the underground garage.
So, several days later the owner was at a strip mall, sitting in a barber chair when another loud explosion shook the building. People ran out of nearby stores to hopefully catch whoever did it.
" IT WAS THAT GREEN TRUCK!!" he heard somone yell. huh???
Sure enough, someone walked in and asked if anyone owned a green Mazda truck. IT JUST BACKFIRED AND SCARED THE HELL OUT OF US
Bewildered, he stopped by a nearby Mazda Dealer and asked a Service Advisor if such a thing was possible. A couple of Service Advisors looked at one another and smiled. they told him if he could leave it for an hour they thought they knew what it was.
They replaced some valve I think and didn't charge him even though the warranty was long expired.
A couple of years later he sold it to a co-worker who loved to play pranks on others. I remember him saying he wished he had kept to old valve so he could have had it reinstalled.
Back in 1973 the first Mazda dealer opened in Louisville. Dad and I received an invitation to a private introductory event(and it really was private I think that we were invited because I subscribed to Road & Track). They had several RX2s and RX33s that you could test drive in a huge parking lot- the place sounded like the howitzer firing range at Fort Knox...
Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive
This time the situation was an easy fix. When the battery is removed the DSC defaults to "Off" and the DSC/xDrive warning light illuminates. The fix? Push the DSC button.
As for the battery function issue, the "mechanic" failed to read-or possibly understand-the entire printout. The warning concerned newer BMWs(basically from the E90-on) that have an Intelligent Battery Sensor(IBS) that adjusts the charging system to the age of the battery. BMW's with an IBS have to have the new battery registered-and in some cases the IBS has to be reprogrammed. The dealer and some Indie BMW shops are able to do this. The thing is, a 2005 X3 doesn't have an IBS.
At this point I suspected that the R&R of the battery may not have been performed properly either- and I was right. The "mechanic" pulled the old battery out without disconnecting the vent tube, breaking the plastic vent elbow that plugged into the battery. So the battery was sitting under the load floor without being vented to the exterior- and the plastic plug provided to close off the redundant vent port on the other end of the battery was just laying in the battery storage compartment(along with the unopened instructions that detailed how to connect the vent tube). Friday I stopped by the dealer and picked up a new vent elbow(it cost less than fifty cents, but my friend at the parts counter provided it at no charge) and I'll install it tomorrow.
Anyway, it turns out my intervention also saved the "mechanic" a few dollars; he was sure that he had damaged the 4X4[sic] system and was preparing to have it flatbedded to the dealer.
And I have told my friend to CALL ME FIRST the next time the X3 has a problem....
Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive
From there, why do you insist on calling who ever it was that slammed a battery into your friends car, in his driveway "a mechanic"?
A mechanic, or technician is someone who has vehicle specific training, and all of the tools required to do a particular job. It also means that they have all of the service information with them so that they can look up re-powering routines when required. Obviously the person who replaced the battery had none of that, and that disqualifies them to have the label mechanic/technician. So the question then is why was your friend so cheap that he didn't call the dealer or a real shop?
As I read this, it wasn't about fixing a vehicle. It was all about how great you are with cars and how stupid anyone who is "a mechanic" must be. Tell us, why are YOU touching his car when you don't have all of the tools and information required to do the whole job? Do you have insurance just in case something goes wrong? Afterall you will be the last person that touched it now!
Now you are familiar with the IBS system on a BMW, that's nice. What about the rest of the vehicle systems that need re-initialized?
BMW's with an IBS have to have the new battery registered-and in some cases the IBS has to be re-programmed. The dealer and some Indie BMW shops are able to do this
Guess again, it's not that difficult to be ready to address this system.
Anyway, it turns out my intervention also saved the "mechanic" a few dollars; he was sure that he had damaged the 4X4[sic] system and was preparing to have it flatbedded to the dealer.
And I have told my friend to CALL ME FIRST the next time the X3 has a problem....
No you didn't. The only thing you have accomplished is the person and business who did this service aren't getting to learn from the mistakes that were made. If it got to cost them more to make it right than what they made installing batteries in someone's driveway, then maybe they would stop doing it and that work would go to real shops and techs who are properly trained and equipped.
Stories like this one do get under my skin, we are always supposed to be humble and get reminded of that constantly. Yet here you are pretending that your God's gift to cars because you think you know how to replace a battery on one car.
Ouch!
Why does it get under your skin that people can solve a problem without having to take a vehicle to some ASE Certified technician? You seem to be criticizing the means, not the outcome.
Truth be told, exactly what is the outcome? Is all anyone had to do is stuff a battery in this and it's done? Why did the battery fail? What about checking for codes that may be set in any system modules for low (or maybe even high) system voltage? Is this being tested to ensure that the charging system is operating correctly? Is there a a drain that killed the battery? Is this going to be road tested with a fully functional scan tool to see if the alternator can meet the vehicles needs, and the PCM's and BCM's expectations for charging system level without having to operate at full capability? Has anyone inspected the battery cables, especially the one specific location that likes to abraid, and then corrode and fail?
without having to take a vehicle to some ASE Certified technician
Do you really think the person who stuffed the battery in this, in the owners driveway is an ASE certified technician, which is at best only a voluntary minimum standard anyway? The O.P. wanted to dump all over "a mechanic" with his story, fine. I ask who is he that he deserves any better than what he wanted to dish out? From our perspective, we can't rid ourselves of either of them, nor anyone else that may want to pretend they know what they are doing tomorrow. But that doesn't mean we have to accept it with open arms.
You would need to stop, set the parking brake fully, and then put the car into park. When you go to re-start the car, shift into reverse/drive and then release the parking brake. It's not necessary for everyone to do this, but occasionally we meet someone who get's the vehicle into a condition that they cannot easily deal with. If using the e-brake solves it then no other repairs are required.
Boy, DIY types really frost you; bitter much?
Stories like this one do get under my skin, we are always supposed to be humble and get reminded of that constantly. Yet here you are pretending that your God's gift to cars because you think you know how to replace a battery on one car.
Wow, pot, meet kettle. As a matter of fact, I have replaced four batteries in BMWs over the past 12 months- in my E36/5, my son's E83, a friends E36/7 and the aforementioned E83. no problems, no complaints.
Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive
I'll let you know if I get a callback. Don't hold your breath.
I ask who is he that he deserves any better than what he wanted to dish out? From our perspective, we can't rid ourselves of either of them, nor anyone else that may want to pretend they know what they are doing tomorrow. But that doesn't mean we have to accept it with open arms.
Once again, my most sincere and heartfelt apologies for taking food from some impoverished tech's mouth. Look, I've been wrenching on BMWs since 1983. I know what problems I can fix, but more importantly, I know when to take/send a car to my indie BMW tech or to my BMW dealer(both of which provide excellent service, I might add). Funny thing; my indie tech and my service adviser at the dealer know all about my DIY propensity and have no problem with it- the reason being that we respect each other as well as our respective talents and abilities.
I might tell you later about how I installed the winter tire/wheel sets on my wife's car and on my daily commuter- I can't wait to hear how I screwed those jobs up... :P
Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive
No, just the arrogance that I saw in your post. I'm really all for being able to take pride in vehicle service, no matter who does it. But I'm not going to sit back and watch someone else get slapped when they don't have a chance to respond, or wrose yet at least get to learn from the event and then maybe not repeat the mistakes if they really occurred.
I think he purposely put the term "mechanic" in quotes to emphasize that the job was botched, and botched in a very elementary manner---I mean, not reading the directions that come with a part is pretty slovenly, wouldn't you say Doc? Not the kind of "mechanic" I would bother to defend.
"Knowing what I do not know" is the mark of a competent DIY person, and should be differentiated from the meat-fisted person who doesn't know what they are doing, but does it anyway.
You failed to display that here.
Based on his responses after I called him out about it, I'm inclined to stick with how I perceived his intent.
Not the kind of "mechanic" I would bother to defend.
They aren't mechanics, so no defense is required and that's the point. When someone goes to a parts store and they slam a battery in, they are not dealing with mechanics/technicians either. These trucks that now run around and install a battery without testing anything are a sham and should be looked at as that. Any suggestion that they are mechanics deserved to be put down.
Mea Culpa...
Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive
I think he purposely put the term "mechanic" in quotes to emphasize that the job was botched, and botched in a very elementary manner---I mean, not reading the directions that come with a part is pretty slovenly, wouldn't you say Doc? Not the kind of "mechanic" I would bother to defend.
"Knowing what I do not know" is the mark of a competent DIY person, and should be differentiated from the meat-fisted person who doesn't know what they are doing, but does it anyway.
FWIW, I agree with your assessment above.
On the other hand, I can see where thecardoc3 is coming from, too. I'd guess the extreme majority of car owners in the US classify anyone who attempts to work on a car as a "mechanic", regardless of ability.
My wife is in the medical profession, and I often hear stories, many from her associates describing so-called "doctors" who have the minimum acceptable credentials, and who quite often turn an uncomfortable medical situation into an intolerable one... Yet, even in those cases (as in modern mechanicals and electronics on cars today), the victims either can't (or don't) differentiate between the legitimate physicians and the "quacks".
It can be a sensitive topic at times...
I once started to anwer a question in another forum (where the poster had a bad experience with the mechanic at a quicky-lube) by saying they had a grammar problem, not a mechanical problem - they used the word "mechanic" to describe the employee at the quicky-lube...
The quote below, made by Donald Rumsfeld, comes to mind. It has validly, regardless of one's political persuasion...And, it applies to any problem solving, even car repair.
From a Press Conference at NATO Headquarters, Brussels, Belgium, June 6, 2002
There are things we know that we know. There are known unknowns. That is to say there are things that we now know we don't know. But there are also unknown unknowns. There are things we do not know we don't know. So when we do the best we can and we pull all this information together, and we then say well that's basically what we see as the situation, that is really only the known knowns and the known unknowns. And each year, we discover a few more of those unknown unknowns.
It sounds like a riddle. It isn't a riddle. It is a very serious, important matter.
There's another way to phrase that and that is that the absence of evidence is not evidence of absence. It is basically saying the same thing in a different way. Simply because you do not have evidence that something exists does not mean that you have evidence that it doesn't exist. And yet almost always, when we make our threat assessments, when we look at the world, we end up basing it on the first two pieces of that puzzle, rather than all three.
And I think that's good in some ways - you can save money by just ripping out the aftermarket alarm or remote start or replacing the gas cap without knowing (or caring) why it's making your car flip out.
As you implied, sometimes its a game of odds, Las Vegas style.
Do I want to make an intelligent bet that my 6 year old OEM battery is going bad and replace it myself for $100, or take it in to a shop and spend $250 to have the charging system checked, only to find out that few OEM batteries last longer than 6 years, and the battery is bad?
For many, they don't have the cash to go exactly by the book, so that make informed "guesses", hoping they'll have the odds on their side.
Applied to cars, we know, say, the basic rules of physics, which have been very reliable, at least where we live in Newtonia. :P
Doc is good at what he does because he is a rationalist. He does not speculate in the face of the unknown (unless I'm reading him all wrong). He falls back on what is known to discover what is unknown.
As for the term "mechanic", that is because we have no established apprentice program in the U.S.
You might remember me telling the story of my friend who runs a Rolls Royce/Bentley repair shop. A trained engineer, machinist and fabricator, he knows what he's doing.
So one day a friend comes to his shop and asks if his son could 'work at the shop, and learn how to be a mechanic".
My friend said sure, if you pay me $1500 a month.
The man balked..."but...but...I thought you would pay HIM!"
and my friend said (paraphrase) "you wouldn't hesitate to pay that for college tuition, but you want me to train him AND pay him? In the first 6 months, he'll cost ME money for the mistakes he'll make and the time I have to spend with him"
The man did not take up my friend's offer, sad to say. The kid would have gotten marvelous training.
having to reprogram your car sounds a bit over the top for just replacing a battery.
And put me in the category of people that if it is at an age where I expect it to be going, and it has all the normal symptoms, I will probably take the 99% option and just replace it (with a basic alternator output test, or whatever it is they do when they put in a new battery).
Now, if the new one craps out, then I would consider investing in deeper diagnostics, but I am not really out anything, since I would have been replacing the battery anyway at this point, "while I was in there"!
And IMO in this story, the "mechanic" was like the scruffy guy with a beat up truck knocking on your door claiming to be a "roofer".
2020 Acura RDX tech SH-AWD, 2023 Maverick hybrid Lariat luxury package.
having to reprogram your car sounds a bit over the top for just replacing a battery.
I would bet that this requirement is coming about due to the significantly increased demands placed on the conventional 12 volt systems by the enhanced use of electrical based components in modern cars today. For years some engineers have pushed to increase the voltage to higher voltage systems so that a small variance in voltage wouldn't have any impact on the performance of these components.
Of course, I'm 58 and I remember the 6 volt systems used in cars when I was young. Other than starter, lights and maybe a radio, there weren't many electrical demands on a car back then.
Let the battery get low on a modern BMW, and all sorts of flaky things start to manifest themselves...
Applied to cars, we know, say, the basic rules of physics, which have been very reliable, at least where we live in Newtonia.
I don't disagree with the rationality of your comment.
If I happen to experience starting problems with my car, I don't automatically suspect space aliens causing the problem, like what happened in an old Twilight Zone episode I remember seeing when I was a kid.
1214 volt batteries around.That is precisely my point. OEM BMW batteries usually fail after 6-7 years. When they do fail they almost always fail completely; barely a click from the starter solenoid, no cranking at all. In the four BMWs I mentioned, that was the failure mode and a new battery was the solution to the problem. As for needing to initialize any subsystems in BMWs of that vintage? I think that would refer to resetting the clock. I do feel bad, though. I guess that I should have sent my friend to the professional technicians at this dealer.
FWIW, a BMW OEM battery for an E60 535i has a MSRP of $210...
Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive
Over the last few hours, the exchange that has taken place here has come a long way. Your car represents one of the paradoxes of the trade. The guy may well have been excellent with all of the normal things that techs had seen up to that point, but there was/is always something new right around the corner to challenge us. Of course there is no way to diagnose what your car did now, but those kinds of events are something techs like myself have had to deal with for our entire career and it's been a thank-less effort for the most part in overcoming them. Even today we have to create our own routines, and tech ourselves to handle the robotics that are in today's cars. The studying never stops, and the cost for the software and tools is racing way past what we can afford.
Just don't drive it more than about a quarter mile from his shop, because that's where it died! He came out and looked at it, and flat-out said "I don't know". And then, almost as if to make him look bad, the car fired right up the very next time I tried it
Yep, cars break whenever they darn well want to. My routine for these situations is a whole set of tools that go into my tow truck with me and I start the diagnostics before the car get's moved. I may not get to come up to the final answer everytime, but I rule out a lot of the system and start narrowing down where the failure is in a hurry.
Always at risk of letting the emotions run away, it's part of the passion for what I do. At the same time, if one never stands up and starts pushing back when sand gets kicked in your face.....
There are cars today that the battery fails like that and they even resist jump starting which really confuses people. The 08 Grand Cherokee we had in the shop (towed in saturday) was a good example of this. Nine of the seventeen modules on the car had codes for low system voltage. The instrument cluster was setting communication codes for the BCM and PCM and as a result was displaying no gage operation of any kind, and all of the tell tales were illuminated. With no communication, the theft system was disabling the vehicle.
Once a new battery was installed, without losing memories BTW, all of the codes had to be recorded and then cleared. Then the rest of the charging system had to be confirmed and that is done with all of the accessories turned on and driving the car under varying conditions while recording specific pieces of information such as charging output desired, the actual voltage level, and the field circuit duty cycle (that's how hard the alternator is working to meet the PCM's goal).
In the four BMWs I mentioned, that was the failure mode and a new battery was the solution to the problem. As for needing to initialize any sub systems in BMWs of that vintage? I think that would refer to resetting the clock.
While many times the cars relearn and no problem is noted, the ones that have trouble relearning we would have consumers return and blame us for the problems, and "all we did was replace the battery". So we had no choice but to investigate each and every event to learn when we had to do resets and exactly what they were. Keep in mind, every manufacturer has it's own quirks, even worse they may have individual cars that require steps beyond any of the rest of their vehicle line. This all keeps getting worse the newer the cars get to be.
Here is a book just for relearning procedures after a car has been de-powered.
http://www.vehicleservicepros.com/article/10449462/tool-review-autodata-battery-- replacement-reset-procedures-manual
I do feel bad, though. I guess that I should have sent my friend to the professional technicians at this dealer.
FWIW, a BMW OEM battery for an E60 535i has a MSRP of $210...
My goal wasn't to make you feel bad, and I hope your's wasn't to get my Irish up. Today what any of us think we know, be one a professional technician or a DIY'er can be challenged in a heartbeat and then another lesson starts. You basically have used what amounts to being lucky that you didn't get overwhelmed during a simple repair as proof of competence when in fact it really only means that you have been lucky. That's not enough for us and the next surprise is always waiting to jump on us and even with decades of real experience and training to avoid having problems, sometimes we still do anyway.
I had a problem with the way you used "mechanic". What some companies are doing and AAA isn't innocent here is employing people with no experience at all, and sending them out to slam batteries in customers cars. Those people are not mechanics. Then techs like me get to clean up the messes they leave behind and once again we are losing what should have been part of the revenues that our up front investments should be returning to us. Worse yet, by association we get blamed for the mess someone else left behind. That is exactly what I saw in your post.
BTW, having to perform a vehicle relearn, even if it was just for idle speed control has been common for every make and model ever since the switch to fuel injection. Occasionally some cars had no trouble relearning on their own, and then you'd have one that by all appearances was identical and it took a lot of time and effort to restore normal operation.
Oh and the book I linked, it's already out of date.....