Chinese Passat LED tail light retrofit

I hooked up the headlight switch's rear fog and front fog pins to the BCM tonight, and found a pleasant surprise: the cluster rear fog indicator works! I don't think it actually turns on an output on the BCM so I'll still have to use a relay to trigger the fixture, but having the idiot light work makes me happy

I think the US coding had a provision for the "full" light switch and expected the rear fog to only be able to be turned on when the switch was in the headlight setting: If it is turned on with the switch in parking it sets an implausible switch fault code.

The idiot light for the rear fog is also half as bright as the other idiot lights (actual warnings), which is nice.

We're insane - Passat interior pieces all over the house, wiring everywhere.

VeeDubTDI said:

We're insane - Passat interior pieces all over the house, wiring everywhere.

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But insane in a creative, nice sort of way. I've jumped onto the LED tail light wagon too and am awaiting my new housings, currently with DHL and in LA. Should have them sometime next week. Ordered directly from Alibaba.

Got the wiring 90% finished tonight, just need to mount the footwell lights Ran out of friction tape, I'll get more and tidy up the last bits. Then the interior can go back in. I'll take pictures as I put it back together for a disassembly how-to.

Hopefully I can get it done before the snow hits

-J

I picked up some 3M 3407NA Friction Tape, 0.708-Inch x 240-Inch for $5/roll on amazon. It's seems to be just a bit thinner than the oem stuff, but good for wire harnesses no-one will see anyways.

Yup that's what I get at Home Depot for not much more.

-J

i will have the last bits of parts on friday and will try this over the weekend. is there still a need for the resistors for the trunk leds once you added the curt converter?
how did you false load the existing harness once it's abandoned so there are no bulb out warnings?
is a relay a must when you run the wire from the euro switch to the rear fog or can it be run directly? relay suggestions?

Sorry guys, I had to work last weekend and didn't get a chance to make a diagram.

Yes, load resistors are still needed. Yes, a relay is needed for the rear fog light.

-J

finished installing the lights and it all works!! well except for the rear fog i still need help with that. i noticed the inner fixtures were not as bright as the outer fixtures with the 100ohm 10watt resistor (fixmy59bug diagram) so i removed it on the left side and now i see now how bright the inner is without it.



i asked at radio shack if a different resistor could be used to get a little brighter and no one there was able to help. this is the part i don't understand, so back to you all. in the thread a 50ohm 10watt resistor was originally used and it triggered the bulb monitor warning for the inners, correct? then a 100ohm 5 watt (compu 85) was used, will this give a little better balance or is this it? i watched the utube videos and it looks like there isn't a big difference for you all.
i haven't added the curt controller yet and will make adjustments then if there is another option.

second point: the rear fog gets wired how?? I pulled a wire to the trunk and before i totally take the car apart and run it forward i need some direction. I have a euro switch and a trigger wire, pin 7 is open, my parking lights already function with no added trigger wire. so does pin 7 get wired to the relay and then to the rear fog or does it go into the bcm/cecm (what pin location) -> relay->rear fog. i have read through some rear fog installations at vwvortex but they don't mention the use of a relay just connections to the cecm with wire swapping to use the drivers side reverse wire...and these are not for the nms. please explain you process i'm smart enough to follow direction but not figure it out!!
thanks!

are you using the trailer harness?

i do have the trailer harness if i need it and have not installed it, just getting things in and running.

woodboy said:

i do have the trailer harness if i need it and have not installed it, just getting things in and running.

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Now that you have verified that everything works, install the Curt controller rather than fiddling with various resistors. All you need is a resistor large enough to satisfy the lamp monitor since your inner fixtures will be disconnected from the computer once you install the Curt.

thanks, i think the curt controller will be the easy part no worries there until i need to know the reistor size, looks like the 100 ohm 5 watt?
step by step.....The following rear fog diy is for a different vehicle.

http://forums.vwvortex.com/showthread.php?4898893-LED-tail-Install-with-or-without-Rear-Fog
am i allowed to do that? apologies if i am not.

ok so i have been following this diy to wire the trigger for the rear fog and pulled the black cecm and pined the wire from euro switch pin 7-> cecm pin 17.

according to the diy i am to pull the left side reverse at pin 28 blue/violet and relocate it. i ran a wire forward from the rear fog and will leave this alone.
next is to pull brown cecm and locate pin 47, pull the existing blue/grn and terminate. what was this wire for?? then insert existing reverse blue/violet into pin 47. this is where i need help. do i insert the rear fog wire i ran forward into pin 47 powering the rear fog and all is good? compu 85 indicated a relay was needed, where does that come into the circuit, is it a generic relay 4 post or vw part?
i appreciate the help, thanks

it's good. the directions don't say anything about running a wire. (like with the mk4) so I wouldn't run one. the stock wire is used and the conversion happens in the CCM/BCM

just follow the directions to a tee and you'll be fine. I used these directions with my mk6 gti and never had an issue.

Now where you may have issues (to my knowledge this hasn't been tried yet, maybe I'm wrong) the GTI and the Passat have different CCMs so this pin 47 may not be an option for the passat. but try and see, worse case it doesn't work and you put it back.

ever think about trying to make the outside lights brighter to match the inside lights instead?

try splicing the positive side of a 10uf/35v capacitor to outside lights power wire then the negative to ground. they should get brighter.

should work for people that want brighter halogen head lights but don't have vagcom.

-Carl

carlrx7 said:

ever think about trying to make the outside lights brighter to match the inside lights instead?

try splicing the positive side of a 10uf/35v capacitor to outside lights power wire then the negative to ground. they should get brighter.

should work for people that want brighter halogen head lights but don't have vagcom.

-Carl

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If you hook it up using the Curt PWM controller, it works perfectly.

In the pic above, the left inner light is at brake light intensity (100%). If you increased the outers to match the left inner, you'd just be running the brake lights all the time.

Final product:
http://www.youtube.com/watch?v=Udul36tZdyY

Ok, after watching the video, it looks like if you just spliced the wires from the outside light to the inside light (dummy load out the inside lights car harness for bulb error), they would perform just like the video using the trailer harness.

-Carl

Simply cloning the lights won't make the little inner LED "bullets" function correctly. The bullets provide most of the contrast between brake lights (bullets on) and parking lights (bullets off). Without the PWM controller and the lights just cloned, the bullets will run dim with parking lights and go bright with brakes giving you much less contrast.

IRISHpride said:

it's good. the directions don't say anything about running a wire. (like with the mk4) so I wouldn't run one. the stock wire is used and the conversion happens in the CCM/BCM

just follow the directions to a tee and you'll be fine. I used these directions with my mk6 gti and never had an issue.

Now where you may have issues (to my knowledge this hasn't been tried yet, maybe I'm wrong) the GTI and the Passat have different CCMs so this pin 47 may not be an option for the passat. but try and see, worse case it doesn't work and you put it back.

Click to expand...

in my case the exisitng left reverse wire also signals the back up camera.
i will go ahead and try.....cold and snowy today!

VeeDubTDI said:

If you hook it up using the Curt PWM controller, it works perfectly.

In the pic above, the left inner light is at brake light intensity (100%). If you increased the outers to match the left inner, you'd just be running the brake lights all the time.

Final product:
http://www.youtube.com/watch?v=Udul36tZdyY

Click to expand...

thanks folks, i will install the curt controller to run the inners and balance the appearance.
my questions are how to get the rear fog implemented. the use of a relay as compu 85 did is what i intended by running a wire to the front,but do not know how to wire it or where to use a relay or what kind of relay.
the diy goes through ecm/bcm using the existing wiring which is great but i use the left side reverse blue/violet to signal the back up camera and reverse. i was hoping to use the wire i ran. was wondering if the exisitng left side reverse blu/violet passes through a relay on its path or if it's dedicated to the lamp from where i would remove it from the black ecm pin 28 and swap it with blue/grn pin 47 in the brown ecm.
then whats up with the blue/grn that is "not used anymore".
is there a source to get a wiring diagram available on line, i think i have seen it referenced. join and download...
thanks again
phil

The rear fog must be connected using a relay since the BCM won't turn on the output with the US coding. I did hook the headlight switch rear fog light output up to the BCM so the indicator in the instrument cluster works, but just tapped into that wire to drive the coil of the relay. I added a new fuse for power for the Curt controller, the rear fog gets its power from that fuse too.

-J

oh boy im all in now. DO NOT FOLLOW IN MY FOOTSTEPS. i have a rear fog at the expense of well ...everything! i unplugged module A and connected the trigger wire to pin 17 and unplugged module C also. i decided NOT to relocate any wires according to the diy i was referencing and went with using the relay so i plugged module C back in. i then wired the relay to the fuse panel for constant 12v and made the appropriate connections for ground, tapped trigger wire for switch, and rear fog wire. hooked the battery back up and turned the car on and woah can you say idiot lights!! my flashlight hit me in the eyes being the biggest idiot of all. everything was lit up. bulb out,esp flashing, traction control,tpms. i figured that disconnecting the battery set the fault codes for everything...so i turned the light switch on and i have no drl in the off position, nothing in auto, i have drl and front and rear parking lights in the parking light position and on position, I have no head lights, no brake lights, no front fog lights, no heat and i don't now what else, but i do have the rear fog. woot! . i pulled the fuse for the rear fogs thinking something might be back feeding from my wiring, but that had no effect. i did reseat module c and try again but same stuff. any thoughts? after you finish with a good laugh
thanks
oh, and no curt controller was installed yet.

What the hell are you doing to your car?

You say you disconnected Plug A and added the wire, and disconnected plug C.

Then you say you reconnected plug C, but make no mention of reconnecting Plug A.

Did you remember to reconnect Plug A?

And are you sure you plugged them both in ALL THE WAY?

VeeDubTDI said:

What the hell are you doing to your car?

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screwing it up apparently, just trying to get the tail lights in with the rear fog. lights are in with rear fog, didn't really expect a bunch bad ju ju when i got it all back together. i crossed no wires and disconnected the battery and figured the electronic modules would retain their programming. as vwnorm put it "blindy going about things".

Fixmy59bug said:

You say you disconnected Plug A and added the wire, and disconnected plug C.

Then you say you reconnected plug C, but make no mention of reconnecting Plug A.

Did you remember to reconnect Plug A?

And are you sure you plugged them both in ALL THE WAY?

Click to expand...

yes i plugged module A back in, it's function, visibly not measuring, is confirmed by the rear fog idiot light on the euro switch illuminating. i will reseat both modules when the sun comes up. All the fuses were removed to add circuits to the fuse panel and will run through them to check for a blown fuse.
live and learn baby there is no other way!
thanks for getting me this far

update: reseated A and C modules instead of using the lever to lock them in i pushed until the lever locked clicked and locked. still had the issue
found a 15 amp fuse for the lighting, climatrol system not lighting up with a tester, replace and the lights all work .
still have steering, traction control, tpms indicators lit and an error for esp in mfi

woodboy said:

still have steering, traction control, tpms indicators lit and an error for esp in mfi

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Well, that's good news...

Three of the four should go away after a short drive to recalibrate itself. You should need to go no further than the end of your street for the steering, traction control and ESP to reset.

The TPMS may just ned to be reset via the button in the glovebox.

Fixmy59bug said:

Well, that's good news...

Three of the four should go away after a short drive to recalibrate itself. You should need to go no further than the end of your street for the steering, traction control and ESP to reset.

The TPMS may just ned to be reset via the button in the glovebox.

Click to expand...

Bingo. The remaining lights will clear very quickly on a short drive.

Glad you found the problem and it was just a dead fuse!

It's all good. I said screw it and put everything back together and drove. Dang lights cleared right out. Now I read this. Man my stress level was way up there!! The fuse story is this. I used a fuse tap (kind that slips over 1 blade) for my v1 the first hour I had the car. I had trouble with the dealer installed tracking system and when I took it back the tech broke the metal tab. He let me know and moved the v1 wire up to fuse six (switched) and pressed the wire with the fuse. I always intended to add a repair to it since I learned about them when installing the back up camera. I wasn't successful then and then learned how to slide the pink lock down to put the repair wire in. Anyway I got the repair wires for this adventure and when I pulled the fuses the broken tab was still in there. When I put them back I noticed the fuse was abit loose and didn't think much of it. Needless to say that was the fuse that wasn't working. I put a continuity test on it and it checked out but just wasn't doing it. When I replaced it all was good. It was dark last night when I tried the rear fog out and everything went to hell.
On to the next !!

Do any of these mods give a bulb out warning on the dash?
I'm considering this LED tail lights, but don't want to deal with bulb out issues.

viperman3 said:

Do any of these mods give a bulb out warning on the dash?
I'm considering this LED tail lights, but don't want to deal with bulb out issues.

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No. Recommend you read through both of these LED tail light threads and review how you want to proceed. Installing LED tails is not plug and play. You can install resistors to fool the BOW sensing circuits, or you can run new wires and get into coding Byte 18 and maintain full functionality, use no resistors and not worry about BOW's.