Community Forums

Unplanned Tourist · 07-21-2017, 10:34 AM

Quote:

Originally Posted by TeJay

zrobotman,

Actually there are a number of sensors that provide voltage signals into the CPU. When those voltages exceed the set parameters then the CPU sets a code.

Remember a code will not be set unless the sensor is sending a voltage that indicates that emissions levels will exceed the limits. I have been out of this for 11 years so some things may have changed. We are still within the area of OBD II. That's short for On-Board-Diagnostics second generation which was implemented in 1996. Since that has not changed I doubt the basic parameters have changed either.

Most CPUs need the fault to occur for a number of seconds before a fault is logged. Rapid short term occurring faults quite often are not logged and therefore very hard to chase down. Sounds like this is or was the problem here in the OP's case. They can be real hair pullers!

JIMBO34PA · 07-21-2017, 05:44 PM

Intermittent faults are the worst to find and fix . I always said i would rather be lucky than good , shaking , moving , tapping and pulling on things many times got me to the cause of the issue . Mass air issues suck because the voltage is so low and varies so much . Good that you are fixed ! You had a tech who was a technician not a parts replacer.

DryCreek · 07-21-2017, 09:07 PM

Quote:

Originally Posted by TeJay

zrobotman,

Actually there are a number of sensors that provide voltage signals into the CPU. When those voltages exceed the set parameters then the CPU sets a code.

Remember a code will not be set unless the sensor is sending a voltage that indicates that emissions levels will exceed the limits. I have been out of this for 11 years so some things may have changed. We are still within the area of OBD II. That's short for On-Board-Diagnostics second generation which was implemented in 1996. Since that has not changed I doubt the basic parameters have changed either.

This is dead-on. Any trained tech worth his ASE certification badge will immediately hook his scan tool up to the port and pull up live data traces. In some cases this is the ONLY way to find a dead/lazy O2 sensor. The MAF voltage should rise slightly with the RPM and TPS changes. You can overlay as many live data streams as needed, depending on the size of your screen. If the computer doesn't see the expected changes, it can go "closed loop" and using some data for enrichment make assumptions from a built in fuel mapping algorithm.

The only real changes since the inception of OBD-II engine management is the use of a bus to tie all of the different controllers together now (ECM/PCM, Body Side Controller, Trans Controller, ABS and sometimes power distribution). The newer CAN-Bus standard started sometime after about 2008. I had to get a new scan tool that was backward compatible to the original iteration. Now, if I could only find someone wanting to sell (cheaply) an old Chrysler StarScan 1 for OBD-I. The I could see what my old Wrangler was up to.....

DryCreek · 07-22-2017, 07:48 AM

Quote:

Originally Posted by DryCreek

it can go "closed loop" and using some data for enrichment make assumptions from a built in fuel mapping algorithm.

Ooops, sorry. I meant to say "Open Loop". Getting old ya' know.

zrobotman · 07-22-2017, 08:10 AM

Boomertex

You are absolutely correct. I am a Civil Engineer that spent most of my life with dirty hands on work. The tradesmen are becoming obsolete. The framer, electricians, finish carpenter, mason, or any other hands on not computer based are becoming none existent. Basic hard workers are as important as the computer geek. I have been around hard hands on worker my entire life an to me they are more fun than the computer geek.

Boondockin · 07-23-2017, 01:22 PM

Being a tradesman... what's even more frustrating and irritating for me is employers filling trade positions with who ever and what ever will show up to work... for the most part... we don't have electricians any more... we have wire pullers called electricians... we don't have HVAC&R technicians anymore... we have parts changers called HVAC&R technicians... part hangers called mechanics... pigs called plumbers... immature punks called engineers ... etc. etc... people that could not troubleshoot their way out of a wet paper bag all over the country with technical titles only! Zero work ethic, zero knowledge, zero character, zero morals, zero desire to learn, want everything handed to them, full of excuses... since they can't razzle dazzle anyone with intelligence they baffle everyone with BS... smart phone junkies...!!!

zrobotman · 07-24-2017, 07:40 AM

You Nailed It.

RV_Fan33 · 07-24-2017, 07:51 AM

Quote:

Originally Posted by Boomertx

There is still in society in general a "stigma" applied to that term "not a future college grad", and I am VERY sure you didn't mean it that way but it absolutely does exist. The sad thing is society looks down on a mechanic or a welder, electrician, etc. while elevating "grads" who couldn't find their arse with both hands and degrees in Liberal Arts. Me, I'd rather have lunch and good BS session with a good electrician

Y'all have a GREAT DAY!!!

Mechanics/welder/electrician/ect. are the backbone of our culture and vitally important!

TeJay · 07-24-2017, 08:20 AM

Several months ago one of my better students found, bought and eventually sold an exotic car he accidentally found while attending a farm auction with his wife who was looking for a rocking chair.

He spotted the tail lights while looking into one of the barns on the property. He talked to the gentleman who owned the place and inquired. Yes the car and another one were for sale and he had done his research and wanted $15,000 for the pair. Eventually they settled on $11,000.

This student took my auto program for three years and also has a 4 year degree in Agricultural Engineering and is working for our local public water district but he still loves working on and does some flipping of cars for extra $$$$.

The "Barn Find" 64 Jaguar went to an auction in AZ and fetched ("As Is" a barn find) a cool $53,000. The owner and founder of "Monkey Garage" bought it.

My student didn't learn his love for old cars and his skills to work on them at a 4 year University.

I've known him since 2000. Attended his wedding in 2011 as his best man and we still remain friends to this day. I'm 73 and he's maybe 30.

Yes a 4 year degree does open doors and it has a place in some peoples lives if done correctly. How many folks are really happy at their job??? How many can have a love or passion for other things and can follow that dream and still make $$$$$ while doing it??

Rvlegaleagle · 07-25-2017, 11:12 AM

What happened with the lawyer....lol

nothermark · 07-25-2017, 12:15 PM

You can add that along with the high schools the two year schools dumbed down their programs in the 70's. They were doing too much remedial work plus the overload of computerization on the old electrical/electronic and mechanical programs pushed the course load above what they could do in 2 years. Some places went to a longer program but most specialized more and skimmed over more of the basics. Don't teach circuit analysis because it is almost impossible when everything is an input or output of a processor that has the code locked away from customer or tech.

computerguy · 07-26-2017, 06:02 AM

Quote:

Originally Posted by TeJay

The same thing that is happening in all areas of manufacturing and aftermarket service and repair.

Today's kids are having fewer and fewer choices in High School. In many HS when a Vocational Teacher retires the program is closed. It saves the district some $$$$ and we know that all kids are going to college and when they graduate they will get a fine well paying job (not).

Even when a kid wants to take a vocational class they are constantly pushed to take college prep courses even if they have no plans on going to college. If their math and science scores are good they are constantly counseled to not take any Vocational classes.

How do I know??? My own Son was counseled every semester to not take Vocational classes.

Secondly what classes the kids are taking they are not exposed to much if any problem solving skills. Yes they have math problems to solve but the teachers know the answers so it's not a real challenge.

Thirdly, the kids are not allowed to fail. Failure is a thing of the past. So the teachers make it easier to get the correct answer so they don't learn to really problem solve. And the teachers keep the parents happy which keeps the administration happy.

You want a real challenge?? Try finding an intermittent open in an electrical circuit. Oh by the way there is no such thing as an intermittent short. If the circuit is built correctly almost any short soon becomes an open (blown fuse) or some burned wire insulation.

The industry can't find well trained problem solving technicians so they are reducing their numbers. They are also reducing the number of item that use to fail. Like spark plugs wires, distributor caps, rotors, points etc.

They've developed sophisticated complex computer systems to alert the customer and technician when something has failed. Many systems have become idiot proof so less thinking is needed or going on.

This may be the prime reason. Ford is still the only game in town so they don't have to keep the public happy. What other gas unit are you going to buy?????

I saw the interview. It is a shame how many jobs there are available an no one trained to fill them
Mike Rowe on VoTech jobs available

TeJay · 07-29-2017, 06:09 AM

It's been great to see someone like Mike Rowe gain so much respect by making the show ("Dirty Jobs") that he did. The world needs all kinds of talented, skilled and educated workers in all fields. The suit and tie worker is not the only place where good, hard, skilled, talented and educated work is taking place.

I may have two college degrees but most of my learning that allowed me to accomplish what I did was learned on the job in the school of hard knocks.

That type of learning occurred when I tried new and different ideas with difficult problems and often I was allowed to and did fail. Over 35 years in the classroom and no two semesters were taught exactly the same. I was ALWAYS trying to improve my teaching skills. Always trying to reach more students in a better way.

Those who don't fail are not trying to accomplish anything. The day that I stop trying new things and stop learning will be my first day below ground.