Joined: 15 May 2007 Posts: 774 Location: Baton Rouge, LA
Posted: Mon Dec 10, 2007 8:10 pm Post subject: Logic Errors, How Do I Know All The Things I Know Are So?
This story was relayed to me by a friend. I thought it showed a darn fine piece of detective work. It also brings out a type of mistake I know I have caught myself making, a logic error.
The car was a four year old luxury model, with 100K miles and in good condition. The vehicle was running fine but one morning would not start. When the key was turned the engine would crank, but not start. The car was towed to a neighborhood shop. They replaced the crank sensor but it still would not start. They continued to look for several days. Somewhere along the line, the starter went out, presumably from age and over cranking, before and during the repair. The starter was replaced. Finally the shop suggested the PCM might be bad. It was replaced but the vehicle still would not start. Eventually vehicle be towed to my friend’s shop, along with the old parts.
My friend’s shop again checked all of the basics. No injector pulse, nor spark and the tachometer did not read when the engine was cranked. The crankshaft sensor leads were read at the PCM. The pattern was present, but weak. All wires tested good as did all grounds. They re-installed the old sensor, same pattern. The sensor was removed and the trigger wheel inspected. It ran true, straight and all teeth were good. The sensor gap was tested and found good.
A spare trigger wheel was attached to a variable speed drill. When the crank sensor was held near the spinning wheel, the crank sensor pattern was good and RPM began reading. Replacing the trigger wheel meant removing and disassembling the engine. The technician was understandably nervous to make such a call. Suppose he had overlooked something? He retraced all of his steps. The crank signal would read when externally stimulated but not in the engine.
This is not meant to be a post on diagnosis, rather one on logic. The problem was eventually solved and was not the trigger wheel. Another tech, in the same shop suggested the old PCM be re-installed. It was and the vehicle re-tested. Now there was no crank signal at all. The replacement PCM was again installed and the crank signal was present but weak. The PCM had likely been the original problem.
He also realized when the drill was used to stimulate the sensor, the starter was not turning. Perhaps a second problem had been created when the starter was replaced. The replacement rebuilt starter might be interfering with the crank signal. The starter was replaced and the vehicle started and ran fine.
The second tech applied a fresh perspective. The first tech assumed the original shop replaced the PCM needlessly, because the same symptoms existed before and after. He assumed he was still looking for the original problem and failed to account for all of the variables.
This example is a diagnostic problem, something with which most of us are familiar. It is as easy to make the same type error in management. It is sometimes difficult to account for all variables in a problem. Unlike the above example sometimes when managers make such mistakes they are not readily apparent. The true results may only show up much later and in a totally different form.
An example could be choosing to use lower quality parts, to save cost. Profits may seem to rise initially, but then problems show up, in the form of lower sales and decreased production. How many such examples can you cite? How many other problems might created by further decisions that deal with the symptoms of the first mistake?
I have heard of a fault in a starter motor causing a no-start. Too much amperage flow created a huge magnetic field, which interfered with the CKP signal. They realized that was happening after they push started the truck.
I know its a management forum, but I couldn't resist answering a technical post.
Joined: 09 Dec 2007 Posts: 21 Location: Lathrop MO
Posted: Thu Dec 13, 2007 12:16 am Post subject:
How do you know the things you know?? You must have confidence in your knowledge. As confidence in your knowledge grows such things as deciding if a computer needs to be replaced becomes easier. Or, if after replacement and a problem persists there are only two remaining possibilties. First the new computer is also bad in the exact same way, an unlikely event to say the least or second there is some other problem also an unlikely event. However, no matter how unlikely one of the two are true. Another example would be the lack of confidence in ones testing techniques of an exciter ring to a crank sensor without disassembling the engine.
Another example may be more on par with the quote you have on the home page right now pertaining to ignorance and arrogance. Perhaps more information could have been obtained from looking at the pattern on the scope beyond simply "weak".
Sorry, I figure you are looking for other examples besides the diagnostic senerio you gave but the questions are so broad and examples so numerous it encompasses practically all of what I believe you started this fourm for in the first place. I figured I'd just stick to your senerio of the diagnostic.
I hope you had a great day Louis. Thanks for all the effort you put into things like this.
Joined: 15 May 2007 Posts: 774 Location: Baton Rouge, LA
Posted: Thu Dec 13, 2007 7:39 am Post subject:
Bud wrote:
I have heard of a fault in a starter motor causing a no-start. Too much amperage flow created a huge magnetic field, which interfered with the CKP signal. They realized that was happening after they push started the truck.
I know its a management forum, but I couldn't resist answering a technical post.
Hi Bud,
It is an unlikely factor, but then so are many of the things that are overlooked in management, with equally dire consequences. I thought it was an interesting story. Thanks Bud, I appreciate the reply.
Joined: 15 May 2007 Posts: 774 Location: Baton Rouge, LA
Posted: Thu Dec 13, 2007 7:52 am Post subject:
Hi Jeff,
Jeff S wrote:
How do you know the things you know?? You must have confidence in your knowledge.
That is a very good observation. I think often the difference in a beginning tech and an experienced tech is just this. As long as the information isn't too far wrong, confidence can be a great help.
I have known people who have debated, analyzed and thought things to death. Sometimes, you have to make a decision, based on your confidence and then make changes as you need to.
Jeff S wrote:
As confidence in your knowledge grows such things as deciding if a computer needs to be replaced becomes easier. Or, if after replacement and a problem persists there are only two remaining possibilities. First the new computer is also bad in the exact same way, an unlikely event to say the least or second there is some other problem also an unlikely event. However, no matter how unlikely one of the two are true. Another example would be the lack of confidence in ones testing techniques of an exciter ring to a crank sensor without disassembling the engine.
Another example may be more on par with the quote you have on the home page right now pertaining to ignorance and arrogance. Perhaps more information could have been obtained from looking at the pattern on the scope beyond simply "weak".
Sorry, I figure you are looking for other examples besides the diagnostic senerio you gave but the questions are so broad and examples so numerous it encompasses practically all of what I believe you started this fourm for in the first place. I figured I'd just stick to your senerio of the diagnostic.
I hope you had a great day Louis. Thanks for all the effort you put into things like this.
Many times knowledge we have is not actually based on fact, rather several positive outcomes. As an extreme example is Chanticleer the rooster. Every morning he rose and crowed loudly. Then the sun would rise. His place in the universe was clearly apparent.
One day he slept in and the sun rose anyway. Chanticleer, cress fallen had to reevaluate his knowledge.
Thanks Jeff, I appreciate your thoughts and look forward to your participation.
Joined: 09 Dec 2007 Posts: 21 Location: Lathrop MO
Posted: Thu Dec 13, 2007 11:05 am Post subject:
That sounds like a wise rooster. He had a belief he held as true all his life. This belief was also very important to him, he knew his place in the world and after only one occurance to the contrary he had the wisdom to re-evaluate his beliefs. Now will Chanticleer have the humilaty required to change or the arrogance to hold onto "the way it has always been"....or the way it's always been done?
Joined: 15 May 2007 Posts: 774 Location: Baton Rouge, LA
Posted: Thu Dec 13, 2007 7:13 pm Post subject:
Jeff S wrote:
That sounds like a wise rooster. He had a belief he held as true all his life. This belief was also very important to him, he knew his place in the world and after only one occurance to the contrary he had the wisdom to re-evaluate his beliefs. Now will Chanticleer have the humilaty required to change or the arrogance to hold onto "the way it has always been"....or the way it's always been done?
LOL (Laughing Out Loud) No doubt, Chanticleer was wiser than the average bird.
Joined: 09 Dec 2007 Posts: 21 Location: Lathrop MO
Posted: Thu Dec 13, 2007 8:41 pm Post subject:
Not that I recall, do tell....Was he a wise rooster? Or, did he fall into a deep drepression finding out the world did not revolve around him after all?
Joined: 15 May 2007 Posts: 774 Location: Baton Rouge, LA
Posted: Thu Dec 13, 2007 9:32 pm Post subject:
Man, I must be slipping. Chanticleer is an example of what I like to refer to as superstitious knowledge. That is things we are sure we know, but are not actually based in fact. This is quite common in current management.
For instance a manager sees an employee turn in a very productive week. He gives him a raise. The next week the employees hours are slightly less. "Damn raise went to his head!" So he gives the pour fellow a KIA [kick in the A..] Next week production rises. Now he has learned. Treat people well and production falls, give them a KIA and it rises.
Had he observed the employees production over time, he would notice it rises and falls every week. It's not likely going to be exactly the same, now is it. If it's up this week, the odds are [averages] it will be lower the next. He could have just flipped a coin or better read a book on statistics.
Chanticleer believed because he crowed each morning and the sun rose, that the reason for the rising must be him. One day he forgets to crow and the sun rises anyway.
Now I believe Chanticleer was a wise bird. He realized his observation did not support his theory, so his theory was revised. Now he knew there was at least one other divine rooster about that was after his job.
Superstitious knowledge? Like a myth? We have a forum bodly named Advertising Secrets, whose title says 'Come in and find out how much you know is myth.'
We could make that friendlier, but it won't help anybody.
Superstitious Knowledge:
1) Techs won't be motivated without flat rate or commission plans. The reality is they become discouraged when too much of their earning ability is in the hands of inept managers, service writers who can't sell, bad tooling and poor company advertising.
2) Customers only care about price, because that is all they ask about.
Joined: 15 May 2007 Posts: 774 Location: Baton Rouge, LA
Posted: Fri Dec 14, 2007 8:28 am Post subject:
Bud wrote:
It came back to me. Tibeux's friend was Ascheel.
Superstitious knowledge? Like a myth? We have a forum bodly named Advertising Secrets, whose title says 'Come in and find out how much you know is myth.'
We could make that friendlier, but it won't help anybody.
Superstitious Knowledge:
1) Techs won't be motivated without flat rate or commission plans. The reality is they become discouraged when too much of their earning ability is in the hands of inept managers, service writers who can't sell, bad tooling and poor company advertising.
2) Customers only care about price, because that is all they ask about.
3) Who wants to add to this list?
4)
5)
6)
4.) You can't charge [the full amount] for diagnosis
5.) People wont pay for OEM parts
6.) I have to have a loss leader oil change to bring people in
7.) An artificially low labor-rate gets people in. It's okay to charge four hours for something that actually takes two. Nobody will know.
8.) People think they're getting a good deal when labor is priced low and parts are marked up 300%. Nobody will know.
Superstitious knowledge? Like a myth? We have a forum bodly named Advertising Secrets, whose title says 'Come in and find out how much you know is myth.'
We could make that friendlier, but it won't help anybody.
Superstitious Knowledge:
1) Techs won't be motivated without flat rate or commission plans. The reality is they become discouraged when too much of their earning ability is in the hands of inept managers, service writers who can't sell, bad tooling and poor company advertising.
2) Customers only care about price, because that is all they ask about.
3) Who wants to add to this list?
4)
5)
6)
4.) You can't charge [the full amount] for diagnosis
5.) People wont pay for OEM parts
6.) I have to have a loss leader oil change to bring people in
7.) An artificially low labor-rate gets people in. It's okay to charge four hours for something that actually takes two. Nobody will know.
8.) People think they're getting a good deal when labor is priced low and parts are marked up 300%. Nobody will know.
9.) Quality is okay but it cost too much
10) Your best advertising is word of mouth. (Disregard Honda, Toyota, etc. on this point.)
11) Pay employees the least they will accept. Promise them raises that are really insignificaint, because they won't figure it out.
12) Comebacks are only the techs' fault. Promise them a bonus if they straighten out.
Joined: 15 May 2007 Posts: 774 Location: Baton Rouge, LA
Posted: Fri Dec 14, 2007 10:39 pm Post subject:
Bud wrote:
louis wrote:
Bud wrote:
It came back to me. Tibeux's friend was Ascheel.
Superstitious knowledge? Like a myth? We have a forum bodly named Advertising Secrets, whose title says 'Come in and find out how much you know is myth.'
We could make that friendlier, but it won't help anybody.
Superstitious Knowledge:
1) Techs won't be motivated without flat rate or commission plans. The reality is they become discouraged when too much of their earning ability is in the hands of inept managers, service writers who can't sell, bad tooling and poor company advertising.
2) Customers only care about price, because that is all they ask about.
3) Who wants to add to this list?
4)
5)
6)
4.) You can't charge [the full amount] for diagnosis
5.) People wont pay for OEM parts
6.) I have to have a loss leader oil change to bring people in
7.) An artificially low labor-rate gets people in. It's okay to charge four hours for something that actually takes two. Nobody will know.
8.) People think they're getting a good deal when labor is priced low and parts are marked up 300%. Nobody will know.
9.) Quality is okay but it cost too much
10) Your best advertising is word of mouth. (Disregard Honda, Toyota, etc. on this point.)
11) Pay employees the least they will accept. Promise them raises that are really insignificaint, because they won't figure it out.
12) Comebacks are only the techs' fault. Promise them a bonus if they straighten out.
who else has some?
13)
14)
13.) You can't find good help these days
14.) We need to educate our customers
15.) It's the economy
16.) If you train your employees they'll just leave
17.) You have to quote prices on the phone
18.) You should study your competition and charge just a little less
18.) You should study your competition and charge just a little less
"Study the competition" is something that gets misused and twisted into several more myths. 'Study and copy' is what is happening.
Mistakes are being copied, small shops are copying dealerships and becoming infected with their practices that alienate customers.
The entire reason we have so many independents is that most people do not like the dealership experience, and stop going to them as soon as their warranty expires. Dealerships have never had over 22 to 25% of the repair market in this country. Why copy them????
Joined: 15 May 2007 Posts: 774 Location: Baton Rouge, LA
Posted: Sat Dec 15, 2007 9:19 am Post subject:
Bud wrote:
18.) You should study your competition and charge just a little less
"Study the competition" is something that gets misused and twisted into several more myths. 'Study and copy' is what is happening.
Mistakes are being copied, small shops are copying dealerships and becoming infected with their practices that alienate customers.
The entire reason we have so many independents is that most people do not like the dealership experience, and stop going to them as soon as their warranty expires. Dealerships have never had over 22 to 25% of the repair market in this country. Why copy them????
Amen my friend. Why not strive to build something much better, that never was, rather than a slightly different "something" that nobody wants anymore?
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