Indie cannot get fault codes..

D

danp

Member
We have a 51 plate A2 TDI, which has been pretty reliable, but recently it has started to hesitate/stutter/misfire at 60/70mph on occasions, and ABS/brake fault lights sometimes come on.

Our local VW indie cannot however get any diagnostic codes at all, he has tried a few code readers, but none have worked. So he suggested taking it to Audi to get the codes.

He said the failure to get codes could be the ECU shorting out, or a fault in the ECU.

Any other suggestions before I book it in with AUDI to have a look?

From a search did see a thread where someone removed the stereo to get the codes (Will in "My VAG-COM port has the wrong wires!") - any other suggestions?

Thanks! Dan
 
Did your indie use VDCS (AKA VagCom) to read the codes? Other readers don't necessarily read them properly (for example, my scangauge doesn't).

Third party stereos sometimes are wired so that you cannot get diagnostics. If you have a standard Audi stereo this will not occur.
 
MikeMarsUK said:
Did your indie use VDCS (AKA VagCom) to read the codes? Other readers don't necessarily read them properly (for example, my scangauge doesn't).

Third party stereos sometimes are wired so that you cannot get diagnostics. If you have a standard Audi stereo this will not occur.
Click to expand...

Thanks for the reply.

Not sure on the reader, will ask him, but he deals with a fair variety of VAG cars so would hope he had one that would work.

It's the standard head unit, but previous owner has added a 3rd party multi-play CD changer, I have no idea if that would make any odds?
 
If the fuel filter has not been changed recently (using a genuine Audi part) I'd try that first. If there is no improvement then it may be the injector wiring harness on its last legs. As a harness gets progressively worse it will eventually flag up injector related fault codes.

Suggest you update your profile with your postal town as there may be someone near with VCDS who would do a scan for you.


Cheers Spike
 
spike said:
If the fuel filter has not been changed recently (using a genuine Audi part) I'd try that first. If there is no improvement then it may be the injector wiring harness on its last legs. As a harness gets progressively worse it will eventually flag up injector related fault codes.

Suggest you update your profile with your postal town as there may be someone near with VCDS who would do a scan for you.

Cheers Spike
Click to expand...

Chs.. updated profile!

Not had a fuel filter recently, think I will get that done with the service then, and see how we get on...

TBH if he can't get the codes I be suprised if anyone can apart from AUDI, but you never know!
 
Thanks for updating your profile.

As far as diagnostics go, VCDS can do everything the Audi dealer can.

Cheers Spike
 
It could just be that there aren't actually any fault codes stored yet?
I agree with the above, get the fuel filter changed first and see where you go from there.
 
If error codes have been logged, VCDS will pick them up.
It's likely that your hesitation issues will be caused by one of the following, none of which necessarily cause error codes to be logged straight away:

1. blocked fuel filter
2. boost leak (either caused by a split intercooler, or a split boost control hose)
3. failing injector wiring harness.
 
So wouldn't all these lights popping up on the dash mean there are definitely fault codes to be read?

I have not used VAG COM (but Indie has been doing so), but sounds like it won't talk to the ECU, he has tried several different machines. (i.e. other types of reader as well)

Would Audi attempt to get the codes via this freebie?! (when checking the "efficiency of your engine")

"
Vehicle Health Check

We offer a complimentary check of your vehicle's main safety-related components, summarised in a written report.

As an Audi owner, you can benefit from a complimentary vehicle health check. It covers everything from the effectiveness of your brakes to the efficiency of your engine. Our expert technicians will let you know of any actions that need to be taken and how urgent these are. It means you can be sure that your Audi stays in top condition.
"
 
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VCDS (formerly known as VAG-COM) can and will do everything Audi's systems will. It runs on a computer (generally a laptop) and is a much more advanced piece of kit than simple hand-held scanners. If your independent garage cannot retrieve the fault codes using VCDS then either VCDS is incorrectly configured or there are faults within your car's diagnostic system and/or engine ECU (unlikely, but possible). If the latter is the case, Audi's systems also won't be able to read the fault codes.

If there are lights on in the instrument cluster, then the car has almost certainly logged a fault code.
You may be within range of a club member with VCDS. If a club member is unable to read the fault codes, then the wider forum can be informed of the reasons why. This will help greatly in helping to fix your A2's problems.

Cheers,

Tom
 
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Well they did a service, inc the fuel filter, I collected it and within a few minutes the ABS, brake warning and traction control lights came on, all at once! (never had this before)

Restarted it a few times but made no difference, limped home on what felt like 1.5 cylinders.

Restarted it up at home, let it idle a few moments and the dash lights stayed off... took it out for 20 mins or so, inc a run up the motorway and all fine. No dash lights on at all, and it drove as normal.

So I guess I'll see what tomorrow brings. Thanks for reading, and the input thus far, have a good w/e!

PS He said he tried VAG COM, snap on and Bosch readers to get the codes, and no luck with any.
 
danp said:
PS He said he tried VAG COM, snap on and Bosch readers to get the codes, and no luck with any.
Click to expand...

This sounds all wrong to me.

For clarity - VCDS (VAG COM as was) is NOT a fault code reader - it is a full diagnostic troubleshooting tool for the VAG range of vehicles.

I think you need to ask 2 questions:

1. Are you using a genuine VCDS or a clone?

2. When scanning with VCDS, did the car scan and just didn't have any fault codes (DTC's) logged or would the car not scan?

The outcome of these questions would be helpful, as if it's a genuine VCDS and the car won't scan then you may have a wiring issue with the ODB11 port or other issues stopping communication to the onboard controllers.

If the car scans fine but hasn't logged a DTC (Diagnostic Trouble Code) then we can look into this further.
Also, any garage worth its salt would provide a hard or soft copy of the scan results to validate their findings.
This information will have the hardware and software versions of VCDS used, and these can be used to determine if the tool is genuine or not.

If the car wouldn't scan, and the tool is genuine, then the Ross-Tech technical helpline would troubleshoot the issue and verify the issue is with the car and not the tool.

Of course you may not get an honest answer to question 1, but again, if the tool is genuine and it scans other VAG vehicles then the Ross-Tech technical helpline can assist the garage in determining what is preventing it scanning your car.

Many clones (copies) of VCDS are unreliable and issues such as they don't show all or any faults or don't work at all are common.

There are several different Snap-On diagnostic tools and I've used them all. Most will show all fault codes, so it's possible there just aren't any faults logged, but considering the warning lamps that have been lit on the dashboard I'd doubt it.

I have no practical experience with Bosh handheld scanners.

I hope this info helps.

Cheers

Jeff
 
Mustang-owner said:
This sounds all wrong to me.

For clarity - VCDS (VAG COM as was) is NOT a fault code reader - it is a full diagnostic troubleshooting tool for the VAG range of vehicles.

I think you need to ask 2 questions:

1. Are you using a genuine VCDS or a clone?

2. When scanning with VCDS, did the car scan and just didn't have any fault codes (DTC's) logged or would the car not scan?

The outcome of these questions would be helpful, as if it's a genuine VCDS and the car won't scan then you may have a wiring issue with the ODB11 port or other issues stopping communication to the onboard controllers.

If the car scans fine but hasn't logged a DTC (Diagnostic Trouble Code) then we can look into this further.
Also, any garage worth its salt would provide a hard or soft copy of the scan results to validate their findings.
This information will have the hardware and software versions of VCDS used, and these can be used to determine if the tool is genuine or not.

If the car wouldn't scan, and the tool is genuine, then the Ross-Tech technical helpline would troubleshoot the issue and verify the issue is with the car and not the tool.

Of course you may not get an honest answer to question 1, but again, if the tool is genuine and it scans other VAG vehicles then the Ross-Tech technical helpline can assist the garage in determining what is preventing it scanning your car.

Many clones (copies) of VCDS are unreliable and issues such as they don't show all or any faults or don't work at all are common.

There are several different Snap-On diagnostic tools and I've used them all. Most will show all fault codes, so it's possible there just aren't any faults logged, but considering the warning lamps that have been lit on the dashboard I'd doubt it.

I have no practical experience with Bosh handheld scanners.

I hope this info helps.

Cheers

Jeff
Click to expand...

None of the mentioned tools will scan the car, as opposed to them not find any codes.. so sounds like some wiring/ECU issue unfortunately...not quite sure what to try apart from taking it to Audi.
 
Well it was something to do with the stereo, once it was unplugged the codes were magically readable and pointed at the injector wiring loom, which has been replaced.. and touch wood all fine since...
 
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