How much are garages charging?

[dobbslc]

So when my diagnostic tool says plug in and turn on but DON'T start the engine it's not necessarily right?
That's interesting as I've sometimes had to start the engine to get it to work.

 

[Cato]

So when my diagnostic tool says plug in and turn on but DON'T start the engine it's not necessarily right?
That's interesting as I've sometimes had to start the engine to get it to work.

It'll run static and dynamic tests, dynamic for anything that only produces a signal when the engine's running, a crank or cam sensor for example.

The software on some aftermarket/non-dealer units can be a little hit & miss. So some of them you need to run it even when it says you don't.

 

[Ubique]

The only time that running the engine will make a difference is when triggering actuators or clearing DTC's, most European vehicle systems will not clear powertrain DTC's unless the engine is stopped.

 

[Ubique]

That's the key thing that many techs don't get.

Something that always sticks in my mind, is an article in one of the trade mags years ago by their diagnostic "specialist", and the key thing that they stressed was diagnostic kit is just another tool in your toolbox.
It doesn't give you the answers, it simply tells you where the ECU has detected something is wrong. It's up to the tech to actually interpret that information, and diagnose the problem.

As I'm sure you have, I've spent many hours reading tech info to actually understand how something works.
Even for simpler stuff, like understanding how the old Transit 2006 fuel filter head worked, which was a revelation in getting them to bleed reliably.

Here's one from today - Sales vehicle from a trader, been in a few times with DPF issues prior to me working there. It's had a new genuine DPF & soot sensor, the owner only does very short journeys to work & back and has been told she needs to do at least a good 30 minute run every 10 days or so (also should have been told she'd be better off with a petrol car...)
Last time it came in, the DPF was reset to 'replacement' again and the trader took it for a 40 min run to allow it to regen.

Came in today, DTC was 'not enough soot level transitions/events' which basically means it's not carrying out a regen, not that the DPF is full. No other DTC's.
Checked live values, immediately the EGT values don't make sense - this has been driven 14 miles in the last 1/2 hour

Ignore the bottom set of graphs, the 'yes' is for each sensor enabled in ECM.
Bank1 sensor 1 - constant 100deg. C.
Bank1 sensor 2 - constant 0deg. C.
The other two sensors show correct values as the exhaust warms up.

Long(er) story short, it turns out there was an SCR fault, which the trader 'got someone in' to delete, this is what causes the values to be as shown.
There is no update available, which would over-write the mess they've made of the software so if they can't put back to standard, it'll cost 'em a new control module...
I'm only using the aftermarket diags because it's a lot quicker than Topix Cloud & datalogger at getting live values on screen.

Traders eh?

 

[Cato]

The only time that running the engine will make a difference is when triggering actuators or clearing DTC's,

and if you want to test operation of sensors such as crank & cam. The static test will look at resistance values and continuity, but as you were saying earlier that's only part of the story.

There's a lot more to diagnostics than many (trade or public) often realise. Is a sensor fault the sensor not sensing? Or is it that it doesn't have anything to sense? Or is it sensing something that is outside the parameters of ecu hardware or software? I guess the other thing is does the person checking know what the input/output should look like?

It's that old saw "Fixing the problem doesn't take long, but it can take you all day to find it."

 

[Ubique]

Agreed - I was referencing the 'plug in and turn on but DON'T start the engine' in the main, although a lot of control modules will block actuator tests if the engine is running.
Sometimes it's useful to compare measured vs. expected sensor values with the engine off and on, for example, pressure sensors should all read roughly atmospheric pressure with the engine off, sometimes it's a good way of detecting things like blocked exhaust back-pressure sensor sample tubes and out of spec differential pressure sensors (most often caused by condensation in the sample lines damaging the pressure cell - it's not just water vapour, it's a weak nitric acid due to the presence of nitrous oxide getting trapped by the water molecules) Sensor tests with the engine running can point to a problem with the engine or a defective/contaminated sensor, but you do need to know the expected range of values.

I really don't know how diag. techs that work in multi-brand environments do it, I've worked for various brands and it can be a challenging time working with just one brand, albeit lots of models and architecture's. Working with maybe five or six brands across a week takes a good breadth of knowledge and the mental agility to make the switch. In theory, they're all similar but the implementation can vary massively.

 

[dobbslc]

other thing is does the person checking know what the input/output should look like?

This is the problem I've had when looking for faults! I can see what's being picked up on the reader but don't necessarily know what it should be.
Is it the sensor the wiring to it or something else?

 

[willie.macleod]

This is the problem I've had when looking for faults! I can see what's being picked up on the reader but don't necessarily know what it should be.
Is it the sensor the wiring to it or something else?

The Picoscope guided test site is a good resource - https://www.picoauto.com/library/automotive-guided-tests/

Even better if you have a Picoscope and software and can access their waveform library, but the above should get you well on your way.

 

[premmington]

Agreed - I was referencing the 'plug in and turn on but DON'T start the engine' in the main, although a lot of control modules will block actuator tests if the engine is running.
Sometimes it's useful to compare measured vs. expected sensor values with the engine off and on, for example, pressure sensors should all read roughly atmospheric pressure with the engine off, sometimes it's a good way of detecting things like blocked exhaust back-pressure sensor sample tubes and out of spec differential pressure sensors (most often caused by condensation in the sample lines damaging the pressure cell - it's not just water vapour, it's a weak nitric acid due to the presence of nitrous oxide getting trapped by the water molecules) Sensor tests with the engine running can point to a problem with the engine or a defective/contaminated sensor, but you do need to know the expected range of values.

I really don't know how diag. techs that work in multi-brand environments do it, I've worked for various brands and it can be a challenging time working with just one brand, albeit lots of models and architecture's. Working with maybe five or six brands across a week takes a good breadth of knowledge and the mental agility to make the switch. In theory, they're all similar but the implementation can vary massively.

Welcome to my life kid...

I went thru a phase years ago when the Euro6 stuff come out - when I had newish low mileage vehicle in for service with no faults - I would plug them in and look at the live data for a good running engine - get a feel for it...

My biggest issue is: Stuff being deleted - things being dropped from the fault code tables - parameters moved - the whole mapping and deleting thing - is the bain of my life...

 

[Ubique]

The Picoscope guided test site is a good resource - https://www.picoauto.com/library/automotive-guided-tests/

Even better if you have a Picoscope and software and can access their waveform library, but the above should get you well on your way.

This one is good, not as broad a scope (!) but free

Waveform Library

Library of automobile waveforms with the ability to quickly access from any device, conveniently search and exchange signals between users. A completely open resource for users of all oscilloscopes.

rotkee.com

 

[m_c]

I really don't know how diag. techs that work in multi-brand environments do it, I've worked for various brands and it can be a challenging time working with just one brand, albeit lots of models and architecture's. Working with maybe five or six brands across a week takes a good breadth of knowledge and the mental agility to make the switch. In theory, they're all similar but the implementation can vary massively.

Hardest part is usually figuring out where sensors are, or what manufacturers have called certain sensors, and aftermarket diag kit that has parameters reading the wrong thing.

 

[Cato]

The Picoscope guided test site is a good resource - https://www.picoauto.com/library/automotive-guided-tests/

Even better if you have a Picoscope and software and can access their waveform library, but the above should get you well on your way.

I have one and it's pretty much my go to for diagnostics.

Hardest part is usually figuring out where sensors are, or what manufacturers have called certain sensors,

That drives me nuts. There's an international scientific language, so why automotive manufacturers all go their own way with names and terms is beyond me. Especially irritating if you're searching for some obscure little part as you have to run through guesses for what it, and what it's fixed to, might be called.

 

[addjunkie]

I have one and it's pretty much my go to for diagnostics.


That drives me nuts. There's an international scientific language, so why automotive manufacturers all go their own way with names and terms is beyond me. Especially irritating if you're searching for some obscure little part as you have to run through guesses for what it, and what it's fixed to, might be called.

Its all part of the conspiracy to make things more complex than they need to be, so the only alternative is to use main stealer and buy new more often.
The future of unsustainable society, cars will become just like throw away electronics, fridges etc. big business will rule the world and the rest will be poor!

 

[Ubique]

I have one and it's pretty much my go to for diagnostics.


That drives me nuts. There's an international scientific language, so why automotive manufacturers all go their own way with names and terms is beyond me. Especially irritating if you're searching for some obscure little part as you have to run through guesses for what it, and what it's fixed to, might be called.

There's the mechanical engine designers, the electronic control designers and the technical writers - all use different terms, even cylinder numbering mech's use 1-8, elec's use 0-7 tech writers use whatever comes to mind! Some start at flywheel end some from crank pulley end.
Sometimes on an unfamiliar engine, I'll pull the connection on the sensor I think it is, and check live data and DTC's for the reading to change or the DTC text to confirm....

 

[Ubique]

Its all part of the conspiracy to make things more complex than they need to be, so the only alternative is to use main stealer and buy new more often.
The future of unsustainable society, cars will become just like throw away electronics, fridges etc. big business will rule the world and the rest will be poor!

I don't care, it's been providing lucrative employment for vehicle technicians - in and out of dealer networks - for as long as I can remember.
And without people buying new cars, the supply of 'cheap motoring' used ones would soon dry up and the prices would rocket!

 

[premmington]

There's the mechanical engine designers, the electronic control designers and the technical writers - all use different terms, even cylinder numbering mech's use 1-8, elec's use 0-7 tech writers use whatever comes to mind! Some start at flywheel end some from crank pulley end.
Sometimes on an unfamiliar engine, I'll pull the connection on the sensor I think it is, and check live data and DTC's for the reading to change or the DTC text to confirm....

I de plug a lot of stuff - to introduce "an open circuit" code - just to confirm I am looking at the right circuit/sensor.

 

[premmington]

I don't care, it's been providing lucrative employment for vehicle technicians - in and out of dealer networks - for as long as I can remember.
And without people buying new cars, the supply of 'cheap motoring' used ones would soon dry up and the prices would rocket!

New cars become three year old cars - they are defleeted from leases - sold on HP to the second owner - then sold as good runners to the third owner - then sold again as end of life cars to people with no money.

Everybody in the chain - needs everybody else. New car buyers need trade in values to part fund another new car - the bottom of the chain needs a steady supply of near scrap stuff. This is whay scrappage schemes mess it up so much - it stops the flow of good used cars to the bottom end of the ladder.

 

[Cato]

Sometimes on an unfamiliar engine, I'll pull the connection on the sensor I think it is, and check live data and DTC's for the reading to change or the DTC text to confirm....

I de plug a lot of stuff - to introduce "an open circuit" code - just to confirm I am looking at the right circuit/sensor.

I do the same, and there are quite a few "WTF?" moments especially when the wire colour randomly changes at some point buried in the loom because they've updated the component. Almost as much fun as back probing the ECU plugs because there's no pin out data available.

 

[premmington]

I do the same, and there are quite a few "WTF?" moments especially when the wire colour randomly changes at some point buried in the loom because they've updated the component. Almost as much fun as back probing the ECU plugs because there's no pin out data available.

I know - I know....

And all the while - you are charging the poor owner by the hour...

It is time consuming and expensive labour wise. If the punter is not willing to pay - you can see how they would agree to - encourage the "parts darts" game - in the vain attempt it fixes it.

But it is the deleted mapped out stuff - the punters are not aware of - that is the real killer. They buy a used car that runs OK - no MIL on - drives OK. Then it gets a another fault - and half the data is missing. And you got a car - with two expenisve faults to repair (the first one been hidden up by a previous owner).

I reckon half the "diesel car park" - at about 7 to 10yrs old has got the DPF/EGR/Adblue/NOX systems tampered with....

 

[Cato]

I reckon half the "diesel car park" - at about 7 to 10yrs old has got the DPF/EGR/Adblue/NOX systems tampered with....

I've lost count of the number of times I've been offered/told to have the DPF deleted and a remap on the Vivaro.