VW Beetle exhaust emission light coming on on dash

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thejazzpianoma, Feb 2, 4:47am
Without wanting to get caught in a fight, that's a very dangerous and naive assumption. From what I have seen a good proportion of the motor trade are quite inept, whether they are qualified or not. Doesn't mean they all are, but far too many are not up to snuff.
thejazzpianoma, Feb 2, 4:52am
I would try another VW specialist. Realistically there should be some stored codes and that aside there are some easy tests that can be done on the likely suspect's that should identify the cause.

While it's possible that it was behaving itself perfectly when looked at, the likelyhood of nothing being stored is pretty slim. I would say it's far more likely that whoever looked at it was not very competent. This is not unusual, even when you go to the dealer. I have seen this scenario many a time.
franc123, Feb 2, 6:40am
Because, amazingly enough, environmental factors can contribute to vehicle faults. Theres bugger all point taking a car to a mechanic to check out a fault that only seems to occur if its raining, driven on a particular stretch of road, parked in a particular place, or even only when its very cold if you don't tell them that's only when it happens, or when those conditions can't be reproduced! For example remote central locking problems, or even a total no go condition can occur when your German car is picking up radio frequencies or signals it doesn't like from your neighbours Chinese TV or a power transformer on the street nearby. Don't laugh this sort of thing actually happens, the jokes on you in the form of a longer diagnostic time if you don't do some self analysis of whats happening first.
bumfacingdown, Feb 2, 6:58am
Sorta makes a mockery of having a car with a magic box with diagnostic codes that tell you what is wrong.
franc123, Feb 2, 7:12am
Its pretty difficult to make something that's totally foolproof, fault codes don't necessarily tell you what is wrong and what you need to replace, they tell you where to start looking. Plugging a scanner into it doesn't mean a quick easy fix every time, why the public believe this is the case is anyones guess. It isn't and never has been like that.
bumfacingdown, Feb 2, 7:16am
Maybe because that is what the public have been lead to believe
franc123, Feb 2, 7:27am
Or what the public WANT to believe. nobody wants to deal with complicated car problems.
mechnificent, Feb 2, 7:39am
With trouble codes, freeze frames, diagnostic modes and component testing. it should be a methodical and systimatic process to find problems in modern cars. more so than ever before.
thejazzpianoma, Feb 2, 7:45am
+1
And there is plenty to go on with an emission light, fuel trim, stored codes, comparing pre and post cat 02 sensor outputs etc. Once you have narrowed it down it's easy enough to then test the suspect component.
bumfacingdown, Feb 2, 7:46am
Someone had to seed that idea and it did not come from the general population
thejazzpianoma, Feb 2, 7:46am
Then call me Mr Nobody. This sort of stuff is a lot of fun, it's like blues clues for adults!
bumfacingdown, Feb 2, 7:50am
Some already do
msigg, Feb 2, 8:11am
Yes franc1 is correct, this is what tarnished vehicle ownership and brands, can't give them away as they age.
ema1, Feb 2, 8:28am
Nah hahhahah no it ain't for those who actually want to get from A to B at a given time or to those who don't particularly want interruptions to their business or daily life.
bwg11, Feb 2, 9:01am
I'm not totally naive with electronics, having taught process control and digital data comms at degree level. The only diagnostic systems I have any experience with are Toyota and ETEC outboards.

Totota workshop manuals give such detailed trouble shooting flow charts,a monkey could do a correct diagnosis.

Hearsay only, but what I hear of some other makes, the manufacturer adopts the MicroSoft philosophy of letting the end user do the beta testing.

Sounds as if cammey's wife's VW might be like this, just pacify the owner with "upgrades" or "re-flashes" until it out of warranty.
ema1, Feb 2, 9:20am
Toyota has brilliant manuals for troubleshooting faults etc I know this too from motor trade experience years ago and long time ownership because they have comprehensive in depth flow charts and common sense data that makes my choice of Toyota an utterly simple one to make and I intend to continue with.
I even have genuine Toyota manuals myself for my own cars but due to not being as able nowadays I leave most to my local Toyota agency service centre when service intervals fall due.
Never needed any troubleshooting visits to date, apart from an electric window issue which turned out to be damaged wiring in drivers door to "A" piller loom due to opening and closing door over time .
That was on a MS137 Crown I owned about 15 years ago.
intrade, Feb 2, 9:35am
Actuarly them 600 pages flowchart to tell a swapatron to dismentel the whole car to check a potentometer! , that is actuarly what comes back to haunt loads of manufacturer. Bacause the advanced electronics cant be diagnosed with flowcharts it would be why these morons dont find any simple faults because they never got told how to diagnose voltage drops and read sensor data from wave-forms of a oscilloscope.
This is on any Make or model with no exemption like renault dealer in switzerland i spoke to trys to tell me its normal when the fuelpump of my mates fully stuffed to the brim with electronics crap . sandero diesel constantly runs the fuel back to the tank, the dealer tells me its normal.
When i my self pushed a wee button on my android nexus 5 and the launch idiag software to stop the friggen pump for a test. Then sure as hell is the ecu comanding the pump on and off.
This problem is huge and manufacturer are actuarly to blame for the way they told to find faults for way to long in the same crude ways of swap-atron flow chart .
intrade, Feb 2, 9:44am
ema1 do you know that a toyota automatic euro 5 emission with hard shift will destroy the gearbox if the fault is not found and fixed . the problem is extreem simple to find but not with a flowchart but with a battery load test
my pico scope has crank start run battery analiser software
the problem is when the battery drops voltage during starting to low the toyota looses its automatic transmission shift adaption value and the programming is to whack the gears in as hard as it can till it relearns adaption
So starting this car often enough with this exact fault will nuke the gearbox, and it will also nuke the rebuilt unit because it is the battery at fault nothing wrong with the rest of the system.
Thats just one problem and no i dont say that will be the fault on any toyota its just a example where you wont follow no flowcharts to find the problem.
ema1, Feb 2, 9:52am
Yes I do know that intrade, but Toyota have more than just flow charts to diagnose faults with and you know that too. I think?
mechnificent, Feb 2, 7:04pm
Those flow charts are long, and do require testing too many components, and so people jump steps.

The whole point of a flow chart is to cover every possibility. they should be a last resort.

We should be aiming to isolate and identify the problem, not eliminate every other possibility.
mechnificent, Feb 2, 7:07pm
Mechanics should listen carefully to what the customer says, and we should question them, including about the weather and road conditions. rain or potholes being common causes of problems.
ema1, Jul 11, 7:02am
That's what I used to do as well as those in the motor trade with me back when I was there doing it.
The more information you can glean from an owner the more directly you can get to the problem.
Today's vehicles though tend to present a rather different scenario but even then owner information about experiencing of faults does make a difference still, depends a lot on how perceptive and how well trained the technician is these days to understand as much as is possible.
Sketchy descriptions of what's happening certainly doesn't help.
Computer fault diagnoses and flow charts and manuals are all there to track down what could present as a problem. skill is the key and lots of purported experts simply don't have ALL the skills.
Time factor to sort issues completely is also a major consideration that can vary from technician to technician and also over all the different car makes out there.
The more complicated vehicle systems become with superseding and updating etc naturally things will be exacerbated beyond the comprehension even of many so called experts.
A lot of folks are controlled by computers, it should always be the other way around, it's actually an all too common form of laziness.