T6 OEM LED-headlight retrofit

[Robert]

Apply modifications to your 55 coding and adaptations as per below.

T6 LED headlight retrofit?

All parts for my retrofit are now ordered with the exception of the plug and play looms. Other than the looms (to keep the install as simple as possible), I am using all used/second hand parts sourced from eBay to keep costs as low as possible. I won't get the warranty on parts that I would...

www.t6forum.com

Edit:
If there is no improvement then there is a problem with your wiring.
Someone else, who I was helping via PM in the past, got a loom which was wired incorrectly.

 

[Dreynolds10]

Hi Robert

Changing to 0FCE now gives me additional faults like it is expecting level sensors on the right hand side (see below). I get that these controllers can be “handed” and my understanding is that the controllers on the RHD are for transporters with the electronic suspension. Which makes me think that the CE and CA in your post should be the other way around? CE for LHD and CA for right?

Either way, that’s a bit of a different topic as whichever code I select I still get the supply voltage for ride height sensor error.

I can confirm my adaptions are as per your post also.

 

[Robert]

For electrically controlled suspension (DCC) there is different bit to be activated in 55. With such a configuration all 3 level sensors are connected to the DCC controller instead of LWR and level signals (front & rear) are fed to headlights range controller via CAN.

In your case I am 100% sure that your loom wires, between range module and one or both sensors are mixed (5V DC, GND, PWM).

 

[Dreynolds10]

Hi Robert

When you say “mixed” do you mean crossed in the wrong pin at the plug? I have taken all pins out of the plugs at leveller end and tested all of them but non give me 5V (or an volts).

I even tested at the Range controller end across pin 10 & 25 with no voltage coming out (so bypassing the loom completely).

If I am not missing any secret/unknown coding for the controller that switches voltage on (can’t think of a reason why that would be a function) then I’m still leaning toward a fault with the controller itself.

 

[Robert]

Measure voltage twice.
Between 25 &12 and then 11 & 10 and report.

EDIT:
Measurement of voltage between 25 & 10 should read 0V DC.

 

[Dreynolds10]

Hi Robert

Yep. I have Zero voltage between 25 & 12 AND 11 & 10.

I can confirm voltage is going in hence why I was thinking the controller is the problem?

 

[Robert]

Disconnect your both level sensors from LWR, clear stored fault codes with VCDS and measure voltages again.

 

[Dreynolds10]

Yep. Same zero Volts

 

[Robert]

I have never seen faulty LWR unit that would allow for VCDS to communicate with it.
Each VAG controller is so sophisticated in its design that it is virtually impossible to damage it by short circuits and wrong wiring.

Can you confirm that your wiring from LWR to both level sensors is as per above wiring diagram?

Can you actually check, inspect each wire individually and verify its beginning and ending?

 

[Dreynolds10]

Hi Robert

Yep, I’ll trace the wires just to be 100%. Also I’m going to swap over LWR from a known working donor (he’s a good friend to let me pull his van apart :-> ). Then I’ll report back.

Cheers

 

[Flyingspanner]

Check to see if you have 5V at any position at the sensor plugs, may just be wired up wrong.

 

[Dreynolds10]

Hi Flyingspanner

I don’t have 5V or any V at the sensor. Did a continuity check on rear and front leveller to the controller so all good there. I lost light so need to complete the continuity check across all wires (PWM included front and back) But I should still be getting 5V at the sensor.

I will do some further testing on the input/outputs at the controller and also try a different one just to rule out the box it self.

 

[Dreynolds10]

Hi Guys

So I have done a little more troubleshooting but still no diagnosis unfortunately.

I have swapped out the Controller from a known working van and get the same result (short to ground). So not the controller.
I have traced the wires from each sensor (5V, GRND, PWM) and all ping back at the controller 26pin plug so no broken wires or crossed wires (verified and confirmed they are all running to the correct pins).
I have removed the battery and tested for continuity across each of the 26 pins and non (except the GRND pin 24 as expected) indicate a short.

I am wondering, would the can hi and/or lo be a possible route for short to ground? I have picked up feeds from the PDC module next to the BMC and these did show a small trace when I did a continuity test with battery removed.

My next test will be to remove the headlight plugs and run fault diagnostics. Not sure whether the 5V out of the controller to the levellers is somehow governed by the return voltage/signal from the motors in the lights so maybe the Short is in that loop and not the levellers.

Any ideas welcome. It’s a shame as the rest of the install went well and short to grounds are a (bleep) to find.

 

[Pauly]

You say you have checked for shorts between all pins and ground but have you checked you have open circuit between all pins going to level sensors, a short between a couple of cables going to the sensor will still report as short to ground (as you will be pulling the voltage down)

 

[Robert]

You have 4 faults identified by your lights range control unit.
Three of them are related to the wiring between the control unit and both sensors.
You need check it again and identify the problem.

 

[Dreynolds10]

Hi Pauly

I have checked each of the leveller pins by setting the multimeter to continuity tone (1 on display) then connecting one Probe to the leveller plug pin and the other probe to the relevant pin in the controller plug. I have checked these for all 6 pins and they all ping or show 0. Is this the test you are referring to?

Cheers

 

[Dreynolds10]

Hi Robert, why 4 faults. VCDS is showing 2. One is calibration which I assume will go once I run adaptation and basic settings so I haven’t focused on this yet until is fix the short to ground

 

[Robert]

Hi Robert, why 4 faults. VCDS is showing 2. One is calibration which I assume will go once I run adaptation and basic settings so I haven’t focused on this yet until is fix the short to ground

Because you have shown us 4 faults ----> T6 LED headlight retrofit?

Can you please post your current full autoscan?

 

[Dreynolds10]

Ah...thats because that scan was done with the levellers unplugged which gives the short to “plus”.

The calibration error Is still there as that needs to happen once I have the short to ground fixed.

so it is the last errror, voltage supply,... short to ground that I am trying to fix.

happy to send a scan (levellers plugged in or out?) but the last error is the one that is consistent that I cannot fix.

make sense?

 

[Dreynolds10]

Just a quick update...it was/is the Controller that is the issue. After much head scratching today I double checked and had closed circuit across all the Leveller Pins Which I obviously should not have. I cleared faults, swapped back to the known good controller, re-scanned and short to ground was gone and I had required 5V at the levellers.

The red herring was the controller was still on the can and all the LED lights were working. It just seemed to have shorted across the leveller sensors. I was curious so stripped it down to confirm. Pic 2 shows the burnt out circuit.

Question now is why/what caused it. Was it like this when I bought it (eBay from Poland but its a 19 year unit so very new). Or have I fried it somehow.

I took the positive feed from the now redundant range control switch and on further testing I think I may have a ground on this switch. Does anyone know if this switched is fused and if so where it lives? The LED wiring diagram doesn’t show a fuse for it So I assume its on a different diagram.

Cheers