Byte 18

[silver1011]

Fine, I've made the member aware of this thread and it is up to them to come here and comment if they wish to do so.

 

The "FWIW" paragraph added no value to your post and it therefore certainly read like it was directed at me.

 

I've only got your word that the software is a copy. Without hearing the other side of the story I won't be telling anyone to "go **** themselves". I used the VCDS members list on here in good faith and got a scan as requested. I'm the one suffering here as it's me who needs help and am now in a difficult position.

 

Perhaps you could offer some guidance on how to spot a copy so that those who don't own or understand VCDS can try to avoid these issues in the first place.

 

Better still assuming you have a record of those who have legitimately purchased the software it wouldn't be too difficult to identify and affiliate those members on Briskoda who are offering to share their genuine version of the software.

[booke23]

FWIW, we do see a lot of people who claim somebody else scanned their car while they actually own the clone/fake and know exactly what they got 

 

I'm sure this is not the case in this particular instance. 

 

 

Better still assuming you have a record of those who have legitimately purchased the software it wouldn't be too difficult to identify and affiliate those members on Briskoda who are offering to share their genuine version of the software.

 

Good idea, although presumably that would require permission from the individual VCDS owners.

 

I know the member was only trying to assist you, but people shouldn't really be offering VCDS services with a fake cable.  

Edited 17 July, 2013 by booke23

[gadgetman]

Sadly cars can be fubared with copied software.

Guess the only way to be sure is ask the member to do an update of their vcds.

Unless Ross tech can do a verified owners list for forums?

[Gizmo]

Unless Ross tech can do a verified owners list for forums?

This is something I looked into a while back, but i was told that it was not possible.

[Phil-E]

Well... I'm not going to hide away here.

 

I have to own up and say that it was me who did the scan for silver1011.

 

Yes I do have a "fake" VCDS cable. At the time I was struggling to find anyone local that would reply to requests for coding and I had just bought a new car so the price tag for the "proper" copy was out of reach so I bought a cheap one off amazon.

 

I do fully intend on purchasing the proper product (probably second hand as the cost new is just ridiculous IMO) as being able to update would be really nice.

 

I have apologised to silver1011 privately. Please do not look negatively on him as he was NOT aware that I did not have an official cable. I was only trying to help.

 

I will also remove myself from the VCDS register to avoid any such incidents in the future.

 

On another note... Theresias... you are rude... *resists urge to swear at you in German*

 

Phil

[Thecko]

 

I do fully intend on purchasing the proper product (probably second hand as the cost new is just ridiculous IMO)

 

I agree the price is a bit eye watering at first but that's probably a bit unfair. I can't say I'm overly impressed with the windows-only nature of the PC Software which is one reason why I haven't purchased a kit myself (I'm waiting for the mobile version before deciding whether to fork out) but the cost won't be purely on the cost of developing the hardware and the host PC software.

 

There's an awful lot of knowledge required of the VAG interface itself (either by reverse engineering (bad) the protocol or by paying VAG (good) for a copy of the spec), and that knowledge and expertise doesn't come cheap. It's only right that they pass the outlay cost of that on to their customers which after all is a niche market so they can't rely on volume sales with tiny margins to claw that cost back.

[Gti Jazz Blue]

OK folks ask your local dealer how much it will cost for a diagnostic scan - it won't take many of them to cover the cost of a cable.

 

I'm on my third (genuine) cable (upgrades from original serial, Twin K-Line and now full Hex-CAN-USB) and have saved myself a lot of dosh by not having to visit a dealer for diagnosis or coding changes.

 

Paid for my original by not having to visit the dealer to periodically reset the airbag light on my mark IV Golf every time someone adjusted the seat.

 

Paul

[Lowen]

IMO, Genuine cable worth every penny!

[silver1011]

I've heard that 1C is the correct byte 18 code for the Twindoor with LED tail lights.

 

As byte 18 is hidden behind the '00' mask if I do try and change it to 1C to try it, how do I go about seeing the original byte 18 in case it doesn't work and needs changing back to standard?

[Liger1956]

As far as I am aware there is currently no way, using VCDS, to view the current setting of Byte 18.

If you cahnge it and it doesn't work then you are in deep troube.

[silver1011]

As I thought, too risky then without being 100% on it being 1C.

 

Why is byte 18 hidden? Is it Skoda or Ross-Tech that have hidden it?

[Gti Jazz Blue]

My understanding is that VAG have masked the value, I guess to stop people from changing stuff and coding changes their self. These days probably even the dealer Tech doesn't get to see that kind of info as it is obtained centrally from the VAG servers.

 

Kind of makes you wonder if the dealers have to have backup Internet connections, as they'd be a bit knackard if their ADSL / Leased Line was down.

[bearthebruce]

My understanding is that VAG have masked the value, I guess to stop people from changing stuff and coding changes their self. These days probably even the dealer Tech doesn't get to see that kind of info as it is obtained centrally from the VAG servers.

 

Kind of makes you wonder if the dealers have to have backup Internet connections, as they'd be a bit knackard if their ADSL / Leased Line was down.

Your understanding is as correct as we know it.  VCDS is not hiding things.....  VAG engineers have decided to do so.

[silver1011]

Looks like changing byte 18 is not going to be an option for me.

 

Not my ideal choice but it looks like load resistors may be the only way to clear the blown-bulb warning.

 

Looking at the back of the lights you can see the incandescent indicator bulb holder (grey holder) and the power supply for the LED's (black seal on the far left).

 

On the Superb there is another cluster on the boot lid that houses the reverse and rear fog light so this main cluster (pictured here) houses the tail light LED's and brake light LED's.

 

I'm unsure which load resistors I need.

 

As the brake light LED's are equivelent to 21W I'm guessing I'll need a 50W 6Ohm load resistor for continuous use?

 

Which wires do I need to bridge with the resistor, is it simply the red and blue wires that are going to the LED's?

 

I thought I would need one resistor for each function (one for the tail lights and another for the brake lights) but as there are only two wires feeding both functions this won't be possible...

 

 

Any help would be much appreciated!

[booke23]

Which wires do I need to bridge with the resistor, is it simply the red and blue wires that are going to the LED's?

 

I thought I would need one resistor for each function (one for the tail lights and another for the brake lights) but as there are only two wires feeding both functions this won't be possible...

 

Although there is only two wires, they are both the positive connections as there will be a common earth for the whole light unit for the negative connection.   

 

I have no experience of adding load resistors for LED lights, but thinking back to my school days........to mimic a 21W bulb, you need to draw 1.75 amps from both wires.......so a 6.85 ohm resistor connected from each wire to earth should do the trick? Here is a rough circuit diagram (not to scale!)

 

                 Red (or blue) wire          

+12v-------------------------------------LED Tail/brake light

                           |

                           |

                   6.85 ohm resistor

                           |

                           |

                        Earth

 

I assume it is ok to use 12v as the operating voltage when carrying out these calculations......because when the engine is running, operating voltage will be around 13.8v.....so you'd need a 9 ohm resister to get the 21W draw.  

[adamal]

I'm not sure this is correct. The canbus measures resistance to determine bulb outage. Resistance on the 21W bulb with a 12V circuit would be V^2/W=6.85 ohms. Much higher than this (ie when a bulb is blown) and the canbus throws the error.

As the wattage of the led set is a lot lower, the resistance will be a good degree higher on a 12V circuit and so the error occurs. To compensate you need a resistor in SERIES with each bulb to use up some of the voltage and reduce the resistance at the led.

Assume the led set is say 3W total. The voltage needed to get a resistance of 6.85 Ohms is about 4.5V (the formula being R=V^2/W, so V is square root of W x R).

So you need to lose the other 7.5V in a series resistor. The current to be drawn by the circuit is W/V=3/4.5=0.67 amps so using Ohms law (V=IR or R=V/I), the series resistor needs to be 7.5/0.67=11.25 ohms.

Of course this is dependent on the 3W figure for the led so the actual wattage will need to be substituted into the calculation when it is done for real. It may also be different for the two different bulbs.

Adam

[booke23]

I'm not sure this is correct. The canbus measures resistance to determine bulb outage. Resistance on the 21W bulb with a 12V circuit would be V^2/W=6.85 ohms. Much higher than this (ie when a bulb is blown) and the canbus throws the error.

As the wattage of the led set is a lot lower, the resistance will be a good degree higher on a 12V circuit and so the error occurs. To compensate you need a resistor in SERIES with each bulb to use up some of the voltage and reduce the resistance at the led.

 

But surely any resistor wired in series with each LED will only increase the overall resistance of the circuit and actually be counter productive.

 

As I see it you need to reduce the resistance of the 3W LED setup......the only way I can think of doing this is having a resistor wired in parallel to earth. ie effectively short the circuit in a controlled manner (through a resistor) to reduce the overall resistance of the circuit.     

Edited 31 August, 2013 by booke23

[RainbowFire]

I'm not sure this is correct. The canbus measures resistance to determine bulb outage. Resistance on the 21W bulb with a 12V circuit would be V^2/W=6.85 ohms. Much higher than this (ie when a bulb is blown) and the canbus throws the error.

 

 

On the Octavia at least, CANBus looks for a specific resistance. So you can have the wrong stop/tail bulb in, it works, but still gives an error.

 

Also, would an error still be shown on the instrument cluster if you have an LED failure, or would the resistor over-ride that and you could end up driving around without a brake-light (for example).

[booke23]

Also, would an error still be shown on the instrument cluster if you have an LED failure, or would the resistor over-ride that and you could end up driving around without a brake-light (for example).

 

Yes, that would be the case. The resistor effectively disables the bulb blown warnings. 

 

But LED's have a lifespan of 50,000 hrs or thereabouts. So they will likely outlast the car!

[adamal]

But surely any resistor wired in series with each LED will only increase the overall resistance of the circuit and actually be counter productive.

As I see it you need to reduce the resistance of the 3W LED setup......the only way I can think of doing this is having a resistor wired in parallel to earth. ie effectively short the circuit in a controlled manner (through a resistor) to reduce the overall resistance of the circuit.

I suppose it depends how the resistance is measured. If it is measured across the bulb only then the parallel circuit will have no impact as 12V will still go through the led and resistance will be higher at the bulb. My understanding was it was based on a measurement across each bulb.

But if it is measured across the whole circuit as a whole I take your point. Having said that calculations would then depend on all the elements of the circuit and it may be hard to balance everything.

[silver1011]

Thanks for the input guys, your electrical knowledge is far superior to mine!

 

When I've been searching for load resistors on the net they are all advertised for situations where people are replacing standard incandescent 21W indicator or 21/5W brake/tail bulbs.

 

In these situations the recommendation is always a 50W 6Ohm resistor...

 

Why do I need 50W when 25W is cheaper?

 

For indicators you need 50W (25W can be used for side lights) the resistors are rated at 50% of their capacity for continuous use. This means a 25W resistor is only rated at 12.5W for continuous use where the indicator you are replacing is 21W meaning the resistor will become dangeroulsy overloaded. It often argued that because the indicator flashes on and off the resistor is not used constantly which is true, but this also means the resistor has between 0.3 and 0.5 seconds to cool in between flashes. So over a few seconds that resistor will become very hot. If you wait for your central heating to turn off and then touch the radiators TEN MINUTES later they will still be red hot! On a 25W resistor if you include a bespoke heatsink with the size calculated for each application and location, mount the resistors using a thermally conductive paste then they would actually do the job. The last time we checked there was no such listing so 25W are not suitable for use in indicator circuits.

 

As the power supply on my clusters are feeding both the 21W (equivalent) brake light LED's and 5W (equivalent) tail light LED's then a 50W 6Ohm resistor would suffice?

 

The main question I have then is if the two wires (red & blue) going to the LED's are positive then do I need two resistors, one for the red (positive) and another for the blue (also positive)?

 

Which wire in the picture above is the negative (i.e the wire to connect to the other end of the resistor/s)?

 

The blue wire looks as though its feeding both the LED connection and the indicator, does this suggest that this wire is the 21W equivalent?

Edited 31 August, 2013 by silver1011

[booke23]

Which wire in the picture above is the negative (i.e the wire to connect to the other end of the resistor/s)?

 

None of them. There are no negative wires when it comes to auto electrics. The body is used as the negative connection. Your cluster's negative connection will most likely be through a screw that mounts it to the car body. 

 

The blue wire looks as though its feeding both the LED connection and the indicator, does this suggest that this wire is the 21W equivalent?

 

I'm not sure. I see there are 3 wires (blue, yellow,red) I assume one is tail lights, one for fog lights, and one for indicator?

 

The main question I have then is if the two wires (red & blue) going to the LED's are positive then do I need two resistors, one for the red (positive) and another for the blue (also positive)?

 

I imagine so, and the same on the other cluster too.

Edited 31 August, 2013 by booke23

[silver1011]

Thanks!

 

There are no fogs in the cluster, there is a separate non-LED cluster that is in the boot lid (see picture below).

 

The only functions performed by this LED cluster is brake and tail (LED) and the indicator (normal incandescent bulb).

 

The only two screws that hold the cluster to the body are those on the far right of the picture above, do you really think that one of these is wired to act as the negative?

 

Edited 31 August, 2013 by silver1011

[silver1011]

I've just checked the original non LED-OEM clusters that are in the garage.

 

They seem to have more wires going through the rubber bung suggesting that these clusters have a separate wire for negative?

 

I've had a closer look at the two securing screws and there is no electrical connection to them. The LED clusters fitted to the car could be different of course!

 

 

Edited 31 August, 2013 by silver1011

[adamal]

I wondered if the extra wires relate to the canbus monitoring??? But on second look that doesn't seem to be the case.