Dim Headlight? Check Relay! (24)

here is the solution .

I tapped into the voltage at the Lima B+ terminal and used a 30A relay to switch power to both low beam headlights.

"As a trigger signal for the relay, I've used the existing low beam headlight circuit, which is controlled by the VW-specific headlight switch. I bypassed the problem with the bulb failure detection by deactivating it using VCDS: Select control unit 17 (instrument cluster);..."
ECU coding -> Function 07; value reduced by 8.

The cable cross-section is 4 mm² from the battery to the relay, and then 2.5 mm² to each headlight.
The cable from the Lima to the relay was fused at 15A (each H7 headlight draws approximately 5A). I used standard 6.3mm crimp connectors to make the connections, and I used a (very) expensive crimping tool from AMP.

Result:
Bitte gib mir den deutschen Text, den du übersetzt haben möchtest.

That's awesome! The voltage drop is now only 0.2 volts, and the light is very white and bright. It's a huge difference compared to before. Halogen lamps have a non-linear relationship between brightness and applied voltage; that's why a "mere" 1.5 volt voltage drop makes such a big difference.
I can only recommend it to everyone .

Best regards, Georg.





Hello,

"The brightness of the low beam headlights on my Skoda Superb (facelift model, 2008) – which is essentially a Passat 3BG without xenon headlights – is annoying."

First, I replaced the H7 bulbs with Philips X-treme Vision bulbs (80% brighter). Before that, there were "Tesla" brand lamps installed, but they made absolutely no difference.

Then I measured the voltage drop. With the engine off, but with the low beam headlights on:
Battery negative to battery positive: 11.95V.
Battery negative to lamp positive: 10.4V.

Okay, so there's a voltage drop of approximately 1.5V. Directly bridging the battery positive terminal to the lamp resulted in significantly brighter illumination.

Now I want to install a relay that will directly supply voltage to the H7 lamps using cables with a large cross-section. I have the following questions about this:

"Are 2.5 mm² sufficient, or would it be more appropriate to use 4 mm²?"

Should I connect the relay's load voltage supply to Lima B+ or to battery positive?

3) Where do I get the power supply voltage for the relay?
On the Passat, terminal 56 on the light switch goes directly to the lamps; there's no relay involved. If you disconnect this wire and use it as a control signal for the relay, the engine control unit (ECU) will have problems with lamp fault detection. If you leave this wire connected, you're shorting the power supply voltage and control voltage at your relay, which means it will never turn off. The lights will stay on constantly.

Is it possible to disable this control unit using VCDS?


I look forward to hearing from you.

Best regards, Georg[/b]

Hi,

Before you install a copper mine mod; in my G VI, the body control module has a dimming function for the headlights to extend their lifespan. From the factory, it was set to 13V. Because of the xenon headlights, I haven't messed with it yet, but I imagine there might be a similar setting in the Superb (no guarantee).

Hi Roger,

Thanks for the tip. I've also heard about the dimming function. However, I couldn't find a dimming module in the wiring diagrams (ElsaWin). Instead, terminal X is directly connected to the lamps.

Best regards, Georg.

Hello Roger,

Sorry for interrupting, but I'm also not really satisfied with my low beam headlights in my Golf VI. I also switched to Philips X-treme bulbs, but it still doesn't quite meet my expectations.

Can you provide more specific information about where I can adjust the dimming settings on the BNSTG?

Thomas K. wrote:

Could you provide me with more specific information about where exactly I can change the dimming settings in the BNSTG?

STG 9 (Body Control Module) -> Perform a long coding process and then examine the individual bytes.

"...but whether a Skoda based on the 3BG platform has a body control module (BCM)... I highly doubt it... unless they added one there. However, it doesn't make sense if it's wired directly through the light switch, in which case it would be like in the first-generation Golf."

The Superb doesn't have an onboard network control unit; instead, it uses a direct connection.
What a crazy design! It's quite a few amperes that have to flow through that tiny light switch.

Then partially connected with cables of 0.75 or 1 mm² size. No wonder that nothing reaches the lamps anymore.

Even my friend's old Nissan has better low beam headlights. Of course, it also has a relay.

Grrr.

Georg_G wrote:

The Superb doesn't have the onboard network control unit installed. Instead, it uses a direct connection. What a crazy construction; after all, it's quite a few amperes that have to pass through that tiny light switch.

Hmm,

No Body Control Module (BCM), but does it have lamp failure detection?
How can they fail at just 10.4V?

Oops... I also wanted to add that I doubt he even has one!

@Roger

Thanks for your feedback. The only problem is that I don't have VCDS, but I have to deal with the VAG software instead.

Would it be impolite if you could describe it a little more precisely, for example, in the following way:

Dimming TFL via NSW (not permitted according to traffic regulations --> see NSW as TFL).
Control Unit 09 Central Electrics > Function 07 Coding > BCM Control Unit > Long Coding Assistant.
Encoding > Byte24 > Enter decimal value as hexadecimal.

Sure, no problem. Here's the translation:

'Thank you in advance.'

Thomas K. wrote:

Would it be impolite if you could describe it a little more precisely, for example, in the following way: Control Unit 09 Central Electrics > Function 07 Coding > BCM Control Module > Long Coding Assistant. Coding >

For now, that seems correct. I once searched for it online, and according to that information, the dimming function should be located on byte 19 of the G VI.

Here's a Screenshot I also found related to it:
http://www.picfront.org/d/7Fnd

Can't you go through the data byte by byte using VAG tools?

Great, thanks!


Is it possible to go through the VAG system byte by byte?

'Yes, it's possible, but with the VAG tool, it's not described as clearly as it is in VCDS. That means I always have to know exactly which byte needs to be changed.'

Not bad how my thread was hijacked here .

But if anyone still has some answers to the questions I asked above, please feel free to share them.


Best regards, Georg.

I don't think there will be much more needed. Use the wire gauge that also goes to the light switch; if you already have 4mm², use that. The lamp monitoring system is connected to the vehicle's main electrical system, which you don't have. I believe your plan should work without any issues.

We did that once back then on a 35i (okay, that's really something) and the difference was huge .

Georg_G wrote:

Not bad, considering how my thread was hijacked here. But if anyone still has some answers to the questions I asked above, please feel free to share them. Best regards, Georg

Sorry, Georg .

I also think that in this case, more is better. At 12V, the percentage voltage drop is extremely dependent on the cross-sectional area. So, use 4 mm², and in my opinion, take the connection directly from the battery (with a moisture-proof fuse).

However, I still see that your problem number 3 remains unresolved, and frankly, I don't know how to bypass the cold diagnosis at this time.

The 11.95 V reading on the battery suggests either active, high-power consumers (in addition to the lights) or a battery that is about to fail. Could the situation improve when the engine is running and no large consumers need to be powered through the central electrical system (due to voltage drops in the wiring and across the rails of the central electrical system)?

matthiasTDI96 wrote:

The lamp monitoring system is connected to the vehicle's onboard network, which you don't have.

Yes, I do. It's not an active component like the onboard voltage control module in the Golf VI, but it still indicates faulty lights.

Roger wrote:

However, I still see that your problem number 3 remains unresolved, and frankly, I don't know how to bypass the cold diagnosis at this time.

Hmm, yeah, that's silly. I was kind of thinking about using a diode. I'll try experimenting with that.

Roger wrote:

The 11.95V reading on the battery indicates either active, high-power consumers (in addition to the lights) or a battery that is about to fail.

This was with the engine off. Hopefully, it's more when the engine is on, but I haven't measured it yet. Nevertheless, the voltage drop will remain, meaning the lights won't produce their maximum possible output. The lifespan of my lights doesn't matter to me at all; I finally want to be able to see properly at night!


Okay, my cables and relays are being delivered by mail today. I'll let you know how it goes!


Best regards, Georg.