Is it possible to read live data from a golf mkIV from 1998?

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RafaelH

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Is it possible to read live data from a golf mkIV from 1998?
to hopefully see what causes my ecu to do the strange things it does.
 
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Uwe

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Sure, but data available will be rather more limited than on newer cars/ECUs.

What engine does this car have?

-Uwe-
 
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RafaelH

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Engine is AKL and the ECU should be an R4/2V Simos HS2439
 
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NEtech

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About 22 measurements blocks
 
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Uwe

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I'm new to the game. Unfortunately, that doesn't tell me anything.
Is there a specific measuring value you're looking for?

-Uwe-
 
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RafaelH

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I'd like to know, why my ecu is making some strage things - sometimes.

The car (cold)starts perfectly, but after only a few seconds something happens and the engine runs very rough. Sounds a bit like if only two and a half cylinders are working.
But it always starts perfectly and runs well for a few seconds. So I'm sure it's not a false air, or faulty ignition cables or plugs.
In my opinion, it must be something that is giving the control unit false information, which then regulates some nonsense.
It's not really much with this car. I think two times temperature, the speed of the crankshaft and camshaft and air mass. The control unit gets that and does something with it.
And I'd like to know whether you can look at the device so closely to know what it's choking on.
From what I know so far, however, it is not (yet) possible in this generation of vehicle.

It would probably be easier, quicker and even cheaper to simply replace all existing and therefore possible sensors. But that's also a bit of flying blind. And I have a bit of an ambition from the days when alternative firmwares were installed on satellite receivers. But that only makes sense if the whole thing is somehow possible in principle. If it's not possible at all with a 27-year-old control unit, then that's just the way it is.
 
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Dr Sheldon

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In my opinion, it must be something that is giving the control unit false information,

So you are eliminating any chance that this could be an "Actuator" issue
 
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The WolfMan

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I would not recommend taking a guess and replace all of engine sensors and hope that the problem is fixed.

If you search in websites likes auto-doc (this applies to any other parts site, this is the most famous one) they are full of cheap garbage parts. Genuine or OE quality sensors may be expensive and you van be spending money for nothing.

A scan tool and/or an oscilloscope will allow you to evaluate your problem and take a "logical" decision rather than a guess.

Answering your question, I think that you can read live data with VCDS from your car ECU. I can do it on a 98 Passat TDI. VCDS is a great tool. Totally overkill for me at the moment, but I don't regret anything.

Consider also get the repair manuals for your car through erwin. Here in Europe you can pay for one hour of access just for 7€ + VAT and an electrical scheme would be very useful.


See this video also. Grounds are important!
 
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Dr Sheldon

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And I'd like to know whether you can look at the device so closely to know what it's choking on.

A multi channel Oscilloscope simultaneously looking at Crank for RPM, o2, Secondary Ignition (all 4) would paint a pretty picture !!
 
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Dr Sheldon

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But it always starts perfectly and runs well for a few seconds. So I'm sure it's not a false air, or faulty ignition cables or plugs.
In my opinion,
Likely a Very Wrong opinion that !!

It is running "Open Loop" for those few seconds !!??
 
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RafaelH

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That's what I think. This "Open Loop" - "Closed Loop" thing
It starts fine, and runs nice for a few seconds. Until it gets faulty values from a sensor.
 
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Dr Sheldon

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That's what I think. This "Open Loop" - "Closed Loop" thing
It starts fine, and runs nice for a few seconds. Until it gets faulty values from a sensor.

In that case you need to narrow it down - Process of elimination.

So long since I worked on these "Vintage" vehicles however if that was put in front of me now I think my approach would be

1. Oxygen Sensor Voltage B1S1 - Graph that MVB from good to bad - What you got
2. MAF
3. Engine Temp
4. MAP


A multi channel Oscilloscope simultaneously looking at Crank for RPM, o2, Secondary Ignition (all 4) would paint a pretty picture !!
 
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Dr Sheldon

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Is there a specific measuring value you're looking for?

-Uwe-
Is it possible to list the 22 MVB's that are available to OP here ?
 
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Dr Sheldon

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Injector durations would be a useful one !
 
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Uwe

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Is it possible to list the 22 MVB's that are available to OP here ?
It might be, if the OP were to post an Auto-Scan. But not without seeing the ID data from his ECU because I don't recall what part numbers an AKL ECU might have.

-Uwe-
 
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Back to the actual question:
We have a 74kW 1,6 AKL with a Simos2 ECU in a Golf IV from 1998. Is this setup delivering any life data that VCDS can read on a running engine? Like tempratures, crank and/or cam revs.

For my use case I add all your posts as a NO.
There seems to be no practical way to diagnose something on this particlar car on my own. Limitations are given by its age.
It can be done .. scope and so on. I'd like to know how to find what need to be fixed. But it'll be more time and money consuming than giving it the car to a pro, that has the tools and the knowledge.

Thans for your input.
 
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Dr Sheldon

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Is this setup delivering any life data that VCDS can read on a running engine? Like tempratures, crank and/or cam revs.
VCDS will only display whatever data that YOUR ECU is configured to deliver. VCDS cannot go in and extract data that is not on offer.

There seems to be no practical way to diagnose something on this particlar car on my own. Limitations are given by its age.
Nope - The limitation is You, Your Knowledge, Your lack of Tooling

It can be done .. scope and so on.
The Scope is an essential tool for the modern day technician - even for a 30 year old car !! All the VM's are now insisting on them.

Scope - Name another tool on this planet that can measure, record and display fast moving signals. For example, from an engine rotating at 2000rpm plus - And be able to catch a glitch in there. Then the opportunity to look at the relationships between several signals ?

But it'll be more time and money consuming than giving it the car to a pro, that has the tools and the knowledge.
I've given you the knowledge and some test plans - Would you like the forum to buy / lend you the tools that you need to fix YOUR car ?

=====================================================================================

Is this setup delivering any life data that VCDS can read on a running engine? Like tempratures, crank and/or cam revs.

Where is the Scan that you were asked for ??

It might be, if the OP were to post an Auto-Scan. But not without seeing the ID data from his ECU because I don't recall what part numbers an AKL ECU might have.

Is it possible to list the 22 MVB's that are available to OP here ?

Why can you not go in and look at the MVB's yourself - They are there !!
You got to do some work to get something back ?

But it'll be more time and money consuming than giving it the car to a pro, that has the tools and the knowledge.
If you can find good one !! Most will start by bolting bits on !!
 
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