A Mechanic's Life - Tales From Under the Hood

thecardoc3

Mr_Shiftright said:

No one goes in an solders up HVAC control modules for instance. They replace them, and on some cars that's a $1000 whack in the head.

Hmm, so I guess I am no-one. I've fixed lots of them through the years as well as Instrument panels, PCM's airbag modules, front control modules........

Mr_Shiftright

Well doc, don't claim to be unique among technicians one minute and then Everyman the next. Which is it?

roadburner

One of my good friends is an airframe mechanic for FedEx; he had a false brake linigg warning on his E30 M3. On BMWs of that vintage a break in the circuit at the sensor(or anywhere else in the circuit for that matter) would illuminate the light. He finally traced the break to the instrument panel PCB; he soldred the broken trace and he was good to go.
The ECU in those cars contained four fuel/ignition maps in the EPROM; you selected a different map by grounding different pinouts. He bought a Turner Conforti chip that had four maps:

1. Valet(RPM limited to 3,000)
2. Stock map
3. High performance map
4. High performance map- 95 octane/race fuel only

He wired everything up to a discarded four position rotary switch out of an old Airbus- complete with LEDs to signify which map was selected. Very cool.

Mr_Shiftright

That is very cool! I wish I had that.

The problem with opening and fixing modules or circuit boards is that the technician can rarely charge enough for the job vs. a parts swap--and he runs the risk of it not working out in the long run.

thecardoc3

Mr_Shiftright said:

Well doc, don't claim to be unique among technicians one minute and then Everyman the next. Which is it?

It isn't ordinary to work with electronics at circuit board level for the corner garage, but there are professional techs with the training and skill to do just that. I happen to be one of them.

Mr_Shiftright said:

The problem with opening and fixing modules or circuit boards is that the technician can rarely charge enough for the job vs. a parts swap--and he runs the risk of it not working out in the long run.

Right on the money.... Pun intended.

Mr_Shiftright

Same with automatic transmissions---fewer and fewer repair shops, even the marque specialists, are cracking open automatics. They don't want the risk of the overhaul not turning out properly. So if say if your MINI CVT isn't shifting properly, and maybe one hour's diagnostic doesn't turn up anything external, your car's transmission is going to be swapped for a rebuilt, and you're going to be out $6500 bucks.

So much for "modular repair" in this case---the repair is 50% the value of the entire car.

thecardoc3

Sad.

Mr_Shiftright

Holy crap! It's interesting that the customer was also injured. What's up with that?

Well my MINI threw a seat bag light yesterday. This was right after I got rid of the CEL for the EVAP system.

I'm thinking maybe I'll just use my MINI's dashboard warning lights for Christmas lighting this year--all those pretty reds and oranges and yellows, blinking at evening falls....how lovely.

Anyway, I disconnected the battery and pulled the connectors off under the seats, cleaned 'em up as best I could, and reconnected, and the light went out (so far, for 24 hours).

WE'LL SEE........

thecardoc3

Mr_Shiftright said:

Holy crap! It's interesting that the customer was also injured. What's up with that?

Some customers insist on going into the shop area. Just ask them, they will tell you that they know all there is to know about auto repair. They will tell you that they have to look over the techs shoulder and watch the techs every move to make sure they are doing it (what-ever) right, soooo.........

We will have to wait until the report comes out. Speculation is that the tire wasn't seating on the bead and the tech over-inflated it trying to get it to pop out and seat. (The specified limit on most tires is 40-44 psi.)
Not sure but some of the details do suggest that the customer and the tech may have known each other since the store wasn't actually open yet. Then again maybe the customer was in a situation that the tech tried to help out early.

It rarely gets much attention, but tech deaths on the job aren't that uncommon. I've had several close calls through the years. The worst of which was when another tech accidently backed a truck into a workbench, just missing me.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwja643plevJAhUCbz4KHeUrBh4QFggdMAA&url=http://www.bls.gov/opub/mlr/cwc/occupational-injuries-illnesses-and-fatalities-to-automotive-service-technicians-and-mechanics-2003-to-2005.pdf&usg=AFQjCNHuvRoSBUJC6cystHT9esLnlguWQw&sig2=tVerwW2luprOdIbFZcwylg

thecardoc3

About the use of a spark plug anti-fouler(s) for the downstream sensor.



California Vehicle Code § 27156


(a) No person shall operate or leave standing upon a highway a motor vehicle that is a gross polluter, as defined in Section 39032.5.5 of the Health and Safety Code. (b) No person shall operate or leave standing upon a highway a motor vehicle that is required to be equipped with a motor vehicle pollution control device under Part 5 (commencing with Section 43000)of Division 26 of the Health and Safety Code or any other certified motor vehicle pollution control device required by any other state law or any rule or regulation adopted pursuant to that law, or required to be equipped with a motor vehicle pollution control device pursuant to the National Emission Standards Act (42 U.S.C. Secs.7521 to 7550, inclusive) and the standards and regulations adopted pursuant to that federal act, unless the motor vehicle is equipped with the required motor vehicle pollution control device that is correctly installed and in operating condition. No person shall disconnect, modify, or alter any such required device. (c) No person shall install, sell, offer for sale, or advertise any device, apparatus, or mechanism intended for use with, or as apart of, a required motor vehicle pollution control device or system that alters or modifies the original design or performance of the motor vehicle pollution control device or system. (d) If the court finds that a person has willfully violated this section, the court shall impose the maximum fine that may be imposed in the case, and no part of the fine may be suspended. (e) "Willfully," as used in this section, has the same meaning as the meaning of that word prescribed in Section 7 of the Penal Code. (f) No person shall operate a vehicle after notice by a traffic officer that the vehicle is not equipped with the required certified motor vehicle pollution control device correctly installed in operating condition, except as may be necessary to return the vehicle to the residence or place of business of the owner or driver or to a garage, until the vehicle has been properly equipped with such a device. (g) The notice to appear issued or complaint filed for a violation of this section shall require that the person to whom the notice to appear is issued, or against whom the complaint is filed, produce proof of correction pursuant to Section 40150 or proof of exemption pursuant to Section 4000.1 or 4000.2.

roadburner

Thanks for the heads-up- much appreciated! Looking back, I guess I shouldn't have installed a Jet-Hot coated H-pipe when the my M6 had the catalyst mysteriously fall off in my garage back in 1994...


In all seriousness, I wondered if you were monitoring my posts- I guess I should be flattered.

thecardoc3

Then you will be disappointed to know that I did see your post, but wasn't looking for it nor you. However, it seems that you do follow mine.

Mr_Shiftright

I'd love to bust someone doing that.

I actually had another trick pulled on me, which I am STILL contemplating taking action on--although probably too much time has lapsed.

About 6 years ago I bought a used car from a dealer and he showed me the CARFAX report---clean. Many years later I bought my own report and saw an accident on it. I called CARFAX to learn the date of the entry of that record. Apparently, the dealer had made a copy of the report and edited out the accident.

isellhondas

Yes, this is EXACTLY why leasing has grown in popularity so much.

Still, those off lease cars have to end up somewhere!

thecardoc3 said:

Sad.

In a former life, I managed a large Sears Auto Center.

I'm guessing it was a split rim. We have talked about these before in these forums. They can be NASTY and some have been known to explode AFTER they have been inflated and taken out of the safery cages.

We had a couple go off in the cage and unless you've seen one you have no idea how powerful the explosions can be. What I can't understand is how the customer was allowed to get close enough to the guy doping the work to get hurt. We wouldn't let a customer anywhere near the inside of the shop.

Yes, very sad!

thecardoc3

Here is an OSHA training film about the danger while inflating split rim tires. https://www.youtube.com/watch?v=s2exMOT0-9M

Here is a film by Branick Industries which demonstrates what happens when a cage is used and a wheel fails.
https://www.youtube.com/watch?v=dKlJJqHFfoQ It's notable that there are a lot of cages out there that aren't strong enough to prevent injury.

I have a problem with the idea that a Sears store would have one of their people deal with a split rim. Those should be left to the truck centers that have people trained correctly and do them all of the time.

It wouldn't surprise me though if the explosion was caused by a zipper failure. https://www.youtube.com/watch?v=eFXVOa44oSE This can happen with passenger car tires especially if a tire doesn't pop past the wheel bead easily. People often make the mistake of over inflating the tire trying to get it to seat. If a weak portion of the tire is in just the right position as the tire finally tries to seat it can rupture violently.

thecardoc3

I was hoping to get permission to paste a post from a different forum here by a dealer technician but haven't heard from him so I'll just have to share the key points.

"J" described the first four jobs he was assigned recently. The first one was a customer who reported that he couldn't pair his I-phone 6 to the car. The next one was an I-pad issue where the customer couldn't get the tunes to pay anymore. The third reported that the airbag (SRS) lamp was flashing on/off. The fourth was complaining about a noise and vibration when driving on the highway.

There was nothing wrong with any of those four cars, the "problems" amounted to the vehicle owners difficulty in dealing with the complexity, and capability of the technology. The first one was that the owner didn't un-pair his older phone. That must be done for the system to learn the new one. The I-pad problem was the result of the owner crushing the cable for the I-pad in the armrest. A substituted cable worked just fine. The third was normal operation of the system at start-up. The lamp flashes during initialization as it performs self tests. The fourth was the real head shaker, it was the haptic seat alerting the driver that she was following the car in front of her too closely.

Each of these problems took time to get the work order, research the issue, attach and use the scan tool as appropriate, communicate with the owners when the systems had no codes or faulty data to give the tech a direction. This even included road testing when it was required in order to get the symptoms to occur. All told these four cars ate up about 1.5 hours of time. "J" is a flat rate technician and got paid "0" hours for these cars because there was nothing wrong that was the fault of the manufacturer.

"J' added another response to the thread. Later that same day another customer reported that the power hatch didn't open fully. The control switch was set to 3/4, the customer didn't know what the switch did. That was another zero on his time ticket for the day.

This is apparently getting to be more common every day that the techs time is being lost like this. For now "J" is fast enough to overcome this lost time and still produce productive days, but that's not how its supposed to work. Every tech is getting their share of these losers and in some cases it serves to force the tech out of the shop whether its the techs choice because of the demoralizing aspect of this or from the dealers because the tech can't turn enough profitable hours from what-ever good work they also get assigned.

thecardoc3

On the lighter side.....

http://www4.ncsu.edu/~mtmorris/index3.html

stever

Some dealers are offering "genius bar" services in the showroom - sounds like having that available would have solved two of J's issues and maybe even the crushed cord one. Those people are on salary.

Back when I did a little computer consulting on the side, I drove across town to look at someone's dead monitor. Turns out she had moved her desk across the room and had managed to turn the contrast knob all the way to "off".

And no, I didn't charge for that one either.

Mr_Shiftright

New car buyers aren't be adequately introduced to all the new gadgetry (often useless or badly designed to begin with) being stuffed into cars because of the intense marketing wars going on now. The lack of uniformity in the designs and interfaces further complicates the issue. When you use an Apple computer, generally someone using one they bought in 2012 can use one bought in 2016. Ditto, the transition from Windows 7 to Windows 10 doesn't require a Vulcan Mind-Meld.

Automakers are generally pretty mediocre (at best) at ground-up computer interface design. They should have Apple or Google do it for them.

thecardoc3

stever said:

Back when I did a little computer consulting on the side, I drove across town to look at someone's dead monitor. Turns out she had moved her desk across the room and had managed to turn the contrast knob all the way to "off".

And no, I didn't charge for that one either.

Now if you had an employee and he/she made that call its one thing as a business if you want to not charge the customer, but would you expect your employee to suffer for that decision? If so, what does such a policy train the employee to do?

Mr_Shiftright

Generally in a well-run business, the service call is a "base rate" no matter how clueless the client is. Doesn't the dealer charge for people who don't know how to pair their phones, if a technician gets involved to figure it out?

stever

It's often a judgment call - I got a lot of other work out of that client.

Mr_Shiftright

Well....if the tech was only busy for 5 or 10 minutes, and I was the dealer, I'd probably let it go as goodwill..."Here you go, sir...no charge on that. I see you're do for a service soon. Would you like to make an appointment now?"

thecardoc3

stever said:

It's often a judgment call - I got a lot of other work out of that client.

That didn't answer the question. Would you expect your employee to pay for your marketing decision?

thecardoc3

Mr_Shiftright said:

Generally in a well-run business, the service call is a "base rate" no matter how clueless the client is. Doesn't the dealer charge for people who don't know how to pair their phones, if a technician gets involved to figure it out?

If they did you see them screaming about having to pay for something when their car was still under warranty here in the forums. Heck they scream here when the car is out of warranty........

stever

>Would you expect your employee to pay for your marketing decision?

I was the employee so it was easy. I think wage and hour would have something to say if I required my employees to do free work.

Which begs the question of why do so many dealer techs put up with that?

Mr_Shiftright

Smashing your phone cord in the armrest is not a warranty item.

thecardoc3

stever said:

>
Which begs the question of why do so many dealer techs put up with that?

More and more are not.

roadburner

You have to love the vehicle owners who won't even attempt to rectify a dead simple problem on their own- such as BT pairing. On several of the boards I frequent I'll occasionally read a question from an owner that can easily be answered by simply reading the OM. In those cases the only answer I give is: RTFM. I've had a few mouth breathers tell me that they are to busy to look it up so I respond that I'm too busy to spoon-feed lazy idiots.

Mr_Shiftright

I actually had to rescue someone in a parking lot because they didn't know how to operate their rental car. The problem turned out to be that you have to press your foot on the brake before the starter button would work. So they were sitting there in the cold for 1/2 hour waiting for a tow truck.

It's sad, really. Not that they didn't "know" instantly what to do, but that they couldn't figure it out.

1. Go to glovebox
2. Extract owner's manual
3. Read index
4. Go to "starting"
5. Be on your way

Time investment? Maybe 2 minutes.

roadburner

Back in the '70s I dated a girl whose father had a new Oldsmobile with one of those moronic "Speed Alert" features. I set it to 25 mph and he actually drove it to the dealer to find out why the car was beeping/buzzing whenever he drove it...

isellhondas

I can't even imagine just how difficult and time comsuming it must be to do a propler delivery on a new car.

When I left the business, it was hard enough but I would have to think it would take at LEAST an hour to explain all of the new technology. That's an hour on a busy Saturday for a slaesperson on straight commission.

And the pressure to have top survey scores is even more intense now than ever!

Mr_Shiftright

The Tesla dealer will spend lots of time with you, but then they aren't selling like hotcakes.

roadburner

And the pressure to have top survey scores is even more intense now than ever!

My BMW sales guy got dinged with a bad survey because he wouldn't drive over to a customer's' house and set up the Homelink remote during his regular work hours- even though he had offered to set it up either before or after work.

thecardoc3

Watch one of these, and you might find yourself watching them all.

https://www.youtube.com/watch?v=79TwUea8E4I

stever

No wonder cars still break down. Where are the 3D printers? Two and half minutes in before a robot even showed up.

Arg - did you see the guy in the red shirt sneeze into the cylinder head?

thecardoc3

Here are some data captures from a vehicle that was setting codes P0128, which is the thermostat sticking part way open and keeping the engine coolant temperature from increasing to full operating temperature fast enough. P1133, which is HO2S insufficient switching B1S1. (Heated O2 sensor bank 1 sensor 1)
P0137 B1S2 (bank 1 sensor 2) low voltage.

Can you see the failure(s) in the data? What is wrong with the car?









BTW. This is an example of what the computer is seeing when it generates a code. I'll add more detail later, or if someone has a specific request. The little arrow at the bottom of each capture is showing which frame of the data is represented by the digital values above the graphs.

Mr_Shiftright

Was coolant level checked?

thecardoc3

Don't worry about the P0128, only the O2 sensor codes are represented in the screen shots. REM P0128 means that from cold start, the coolant temperature didn't rise high enough in a specific amount of time.

Mr_Shiftright

Well my Dad told me always to look first at the obvious.

thecardoc3

So follow his instructions and try again.

isellhondas

Mr_Shiftright said:

The Tesla dealer will spend lots of time with you, but then they aren't selling like hotcakes.

The aren't selling well? Really?

I can't go a day without seeing at least one Tesla and I've seen as many as four in a day and I'm not looking hard.

Must be those Microsoft/Amazon/Costco people with nothing else to spend their money on.

I doubt if there are many in South Dakota!

Michaell

isellhondas said:

Mr_Shiftright said:

The Tesla dealer will spend lots of time with you, but then they aren't selling like hotcakes.

The aren't selling well? Really?

I can't go a day without seeing at least one Tesla and I've seen as many as four in a day and I'm not looking hard.

Must be those Microsoft/Amazon/Costco people with nothing else to spend their money on.

I doubt if there are many in South Dakota!

I saw an article that stated that Tesla delivered just over 50,000 vehicles last year.

A majority of them, I suspect, in states with big incentives or folks wanting to be on the cutting edge.

Mr_Shiftright

They're selling pretty well but $100K cars don't exactly fly out the door. And they still haven't posted a quarterly profit except one time, and that was using the "new math". Now that Mercedes is seriously jumping into EVs with both feet, we'll see what happens in the next few years. We know who their target is.

explorerx4

I've seen a couple Tesla's in Madison, WI when visiting. Both times in October.

toomanyfumes

I've only seen one around here in the Milwaukee area. Saw a bunch in San Francisco and San Diego when we visited California last summer.

thecardoc3

Hmmm. Doesn't anybody have any idea how to use that data? If you click on the blocks at the bottom of that post that opens up the full screen shots of the data captures instead of just the thumb-nails if that helps.

thecardoc3

The data in the above captures show;
The short term fuel trim in red,
The long term fuel trim in green,
The upstream O2 sensor in dark blue,
The downstream sensor in light blue,
The upstream O2 sensor heater current as measured by the PCM in purple,
The downstream O2 sensor heater current in yellow.

If you open the captures in a picture viewer, you can zoom in and examine each of the traces more closely than you can here in the forum.

In order to diagnose any failure you have to understand the basics of the system in question. That is what these six traces represent, just the basics of the O2 sensor operation and fuel trim as associated to that input. In order to have the O2 sensors output an accurate signal, they have to be in the correct temperature range and that's what the heaters are for.

The first clue that something is really wrong with the values in the captures is the short term trim changes. The less that short term trim has to move in order to get the upstream O2 sensor to switch from rich to lean and back the better, in fact it should be around 6% total at the most. In the captures the short term trim moves from a positive 17% correction to a negative 13% correction repeatedly, that's a total of 30% fuel trim variation and easily enough to cause a noticeable change in the engines operating characteristics. The question then becomes why is it doing that. Is the sensor bad? If you google the associated trouble code mentioned you will find no shortage of advice that will tell you to replace the sensor. But is it really bad?

Now look at the trace that represents the upstream O2 sensor heater current. See the spikes that are going up to two amps of current and then all the way back down to zero? There is a problem with the heater circuit and the sensor is too cold to work correctly. That could be a problem that is inside or outside of the sensor and you have to test and prove which is the case this time.

What tools do you need, and what testing routine(s) do you need to utilize in order to identify the exact cause of this failure?

It is OK to admit that you don't know how to proceed if that is the case, but realize this is a very simple failure and just think about what that means the potential is for the really tough ones.

qbrozen

Teslas are VERY popular in NJ.

Doc, I have no idea how to read that data or what any of those things mean. If I stare at it long enough (which was about 120 seconds), the pink and red lines look weird and inconsistent to me. That's all I got.

Edit: Doc's above post got in just before mine. Sounds like I was at least looking at the correct lines.

thecardoc3

If the ability to upload more advanced data stream captures was possible I could link a section of the capture that would allow you to see the data in motion, and that might have helped. If you open and save each of the captures as is, and then click through them, you can get a similar effect. Each of those screen shots is one data frame of the ninety that can be displayed in that format. That ninety was selected out of the 661 total that were stored during that part of a road test. At the same time, if you notice the cursor at the bottom, the captures chosen skip over a number of that are frames in between them. That actually mimics one of the differences between what a factory scan tool can do as compared to an aftermarket one. The factory tool allows for each frame shot to be viewed, while the aftermarket updates so slowly that a lot of data is missed by the user. The nightmare there is while I chose peaks of data to single out from the factory tool capture, you would have no idea if the values you were seeing with the cheaper tool represented the average values, some peaks, or just an anomaly.

BTW the really tough ones can be dozens of pieces of data and include both engine as well as transmission inputs and outputs.