Here is a tipical case story dealer level morons

Not just here its a world wide phenomenon.
2010 Mazda 3 i 2.0L Abs, Ehpas

Salt Lake City, Utah so i would assume the dealer mazda is from near by .
copy pasted.
All the abs and steering indicators lit on dash. Power steering does work but abs does not. Code u0140 in abs and power steering module. I can communicate with both modules with my launch scanner and read data stream. I have tested the can low and can high wires from both modules to bcm. The abs module and bcm have both been replaced (new units). The dealer says the abs is plug and play, the bcm I had reflashed by them. When I disconnect either module, the pcm sets communication codes. While at the dealer for the bcm programming, they went ahead and diagnosed the problem to be the power steering module. Luckily I had another mazda 3 that I could swap steering modules. No change at all. Has anyone seen a pcm or instrument cluster set this u0140 in the abs and steering module? Maybe I do need a new steering module and get it flashed by the dealer but is there any way to test this and know for sure? Anything I can look for on the scope? One more thing, I did scope out the can lines at the steering and abs module and compared to the bcm and the waveforms match perfectly with eachother. Thanks for the help and insight.

people can reply and help on this professional forum and here is the fix he posted Read what the mazda DEALER diagnosed and what it really was in the end. scot whom seems to be a tech who replyed to hes case has helped him to figure what is wrong for real.

FIX posted on Dec 31, 2015 6:47:23 PM

Scott, you are the man. Just before your reply I started checking all the components in the steering/ abs system. Ends up that this car had the wrong clockspring (steering angle sensor plug just hanging there). To be sure I unplugged the angle sensor on another mazda 3 and sure enough, u0140 in the abs and ehpas with no other codes. Changed clockspring with the correct part and problem solved. Thanks for all of the help. I have spent many hours on this car and lots of money.

I think that's more a case of why amateurs shouldn't attempt to fix cars more like, why such meddling actually makes things harder for dealers, and why aftermarket scan gear that simply doesn't have the functionality of the proper gear is also not a good idea, the aftermarket tool probably couldn't figure out the full CAN layout. I bet it wasn't divulged up front to the dealer tech that somebody had attempted clockspring replacement, not fitted the right part and not plugged it in, or said why it was replaced in the first place. It also doesn't say who ordered the EBCM and BCM to be replaced. The SAS is obviously a stand alone module in that car as opposed to being just a sensor, there should have been more codes logged in the EBCM if it was only a sensor, likewise there should have been codes relating to drivers airbag too. Only a proper module presence check by the Mazda scan tool and/or monitoring the SAS data in the EBCM MAY have picked that up quicker. Its not like it was a straightforward component failure.

yes but the code puts you in the right direction franc123
the u 1000 is not from the case study if you have a u1000 your alarm bells should go off that somone has erased codes and hoped the codes dont returns again instead of found the problem and fixed it before erasing.
Also i know a good thing is with some of them onehung-low tools you cant erase some factory codes so the problem is when some semy-professional without a 300$ flashlight and a 10 tausend $ tool erases codes because thats how you fix cars , that is the real problem.
onehung low tools just say no code present as they are only global obd2 emission code interpreting libary tools. So the average joe with onehung low tool dont casues extreem problems its the other morons like a moron behind a factory level tool.

Thanks for reinforcing the fact that aftermarket tools aren't really much use, in this case the presence of the U code proved nothing other than there is a networking problem, there was no other indication that a specific component COULD have been faulty.

and yes launch is extreem poor on mazda its good on toyota and nissan mitsubishi and is good on basic stuff for most car makes.
like i actuated everything with launch idiag on our dacia sendero, apart from the rear windscreen whiper that comand did not work .
but i could disable injectors for relative compression check. turn on fuelpump turn on front whipers. turn on evap purge silanoid , turn on fuelpump in tank . almost everything you could think off on the budget little electronic dacia sandero
it was the reason i got me all asian software for the tool afterwards.
dont need vw as i got factory level rosstech for that purchased benz and sprinter , for benz i am not happy with launch the diesel stuff is missing and so was it missing for the dacia diesel.
i will get j2534 cardaq- plus as my next tool as all manufacturer move to j25- 34 i got a good video if your interested from derw-tech
they make the j2534 for snapon thing is snapon has validation from some car maker and drewtech dont one one make, the tool is the same just snapon have the firmware with approval loaded from manufacturer.
i guess drewtech will request they add them on approfed also but the manufacturer dont has to they only need to have 1 minimum j2534 tool maker as aproofed by law.

https://www.youtube.com/watch?v=deVK0wfYGRE

franc123 i am going to bash fiat now on the case i know off it did blow my mind when i first started learning all this stuff and i only know about 25% of what one needs to know , but this is true what i write now.
I know a guy in switzerland he is a Fiat autorised dealer back in 2005 to2010 that story is from so things might have changed since.
i spoke to that guy fiat demanded he tile his showroom with the tiles color they told him to or they cancle his fiat dealer license.
Right so i think he must have a factory fiat tool for diagnostic. nop fiat dont give him anything silch information nor any form of scantool . He said if he needs a scantool he hires it to use from parts supply like repco there is parts supply guys.
i knew you need a factory scanner to scan cars since 1996 due to that i am a sortof vw fanboy of kind.
Right so its more important for fiat to have fancy tiles then the guy whom services new cars to have a propper scanner?
later on in 2010 or so he had some form of fiat scanner.
i wanted him to scan a jtd diesel alfaromeo. He hooked his fiat scanner and gets a no comunication .
i used back then the global obd2 scanner from elm, i did not know that my tool was only emisson codes .
but he got no comunication at all . WTF fiat ! that guy is a main dealer and sells new cars well not alfa but geez . its slowly becomes more and more clear why the manufacturer breed a ton of swaptrons . when fiat dont think there new car sellers need factory level scanners.
its not only fiat almost all manufacturer seem to dohave done this
its important to have tiles matching the shworoom spec but fixing repair tools whom cares not required . w.t.f!

This now comes back to haunt manufacturers of cars.
also another thing i did learn manufacturers cut engeneers from production in 1980 you had like 2000 engeneers working and testing things as a example now only 250 do that work , so the consumer becomes a test pilot of the untested crap they release whom afterwards needs reprogramming to fix faults .
Like when somone in his PSA crap bashes at full spped in to a wall because the engine reves on its own with key out of ignition at full blast.
To name one example of the pile of crap citroen.
that is the reason behind why cars rev on its own because its untested underengeneerd pile of crap where the manufacturer wants to save money on propper testing and turns buyers in to there test pilots.
just make unknowen codes and blame the driver right. a bit like fiat where tiles is the most important thing to meet up to.
Have not seen any fiat rev there guts out by them selfs . but whom knows p.s.a crap definetly do this.

Sounds rather like 1950s and 60s English (and other?) cars: When a new model was introduced it was left to the buyers to discover all the design and assembly faults! It was often better to go for the last version of previous model than an all-new car.

^^^ Yes when brother bought a new mk 2 escort in 73the diff was noisy , so the dealer tried 3 until found 1 that was ok . Said Ford didnt bother setting up the p;inion to the crown wheel anymore just swapped them out until, got a good 1.

I bought a new 2 litre Cortina in the same year, it also took three goes to get the diff quiet.

I remember the brochure mentioned NVH (noise vibration and harshness), an acronym I'd never heard of before. I suspect Ford invented the term just for the Mark 3 Cortina. You would go a long way to find a vehicle with more NVH. Noisy diffs, critical adjustment of the diff nose piece angle, problematic driveshaft centre bearing, road noise etc, etc.

Its very much a result of letting marketing men and accountants run the show, they're not interested in why a development engineer says this part needs to be made to this standard and needs to be proven for this long under lab conditions. they will go blank on you. All they want to know is what it will cost, will it help convince someone to buy the car and is it a Key Selling Point over the oppositions product? The goal is to sell as many cars as possible, at the lowest unit cost whilst minimising warranty claims and ensuring safety and emissions requirements (IF you're honest about it) are met. That's it.