Trunk latch hack/open without a key or remote?

I was wondering if there's a hack to get the rear lid on my Golf to open without using the key, the remote, or the switch on the driver's side door card. I've seen this on two other Golfs, where you could open up the rear just by using the handle (a la Mk6 style).

What I did was cut one of the wires going to the lock solenoid and install a switch.

When the switch is on, the hatch locks every time it is closed

When the switch is off, the hatch latches but does not lock.

There are more elegant ways to do this, but this is the easiest.

pkhoury said:

I was wondering if there's a hack to get the rear lid on my Golf to open without using the key, the remote, or the switch on the driver's side door card. I've seen this on two other Golfs, where you could open up the rear just by using the handle (a la Mk6 style).

Click to expand...

There's a bit you can flip with VDS-PRO (an old-timey DOS-based app that uses a serial-interface OBD cable; serious old-school VAG-COM-like.) That's what I've done with every Mk4 Golf / Jetta wagon. If doors are unlocked, hatch is unlocked.

There's also a wiring hack you can do which basically takes the signal from the rear door wiring and extends it to the rear hatch. Can't remember what wire, but it's written up here somewhere.

(Edit: My recent exercise - some links in here..)

NarfBLAST said:

What I did was cut one of the wires going to the lock solenoid and install a switch.
When the switch is on, the hatch locks every time it is closed
When the switch is off, the hatch latches but does not lock.
There are more elegant ways to do this, but this is the easiest.

Click to expand...

Nice, another Paul. That's tempting, except when the car is parked and the alarm on. Or rather, door locks engaged (because seriously, who even pays attention to car alarms anymore?)

Nuje said:

There's a bit you can flip with VDS-PRO (an old-timey DOS-based app that uses a serial-interface OBD cable; serious old-school VAG-COM-like.) That's what I've done with every Mk4 Golf / Jetta wagon. If doors are unlocked, hatch is unlocked.

There's also a wiring hack you can do which basically takes the signal from the rear door wiring and extends it to the rear hatch. Can't remember what wire, but it's written up here somewhere.

(Edit: My recent exercise - some links in here..)

Click to expand...

I have yet to view your link. I gotta lock up VDS-PRO now. I actually have several old 486-based laptops that are fully functional (rebuilt the battery, but that's because I collect this stuff). I love VCDS, don't get me wrong, but a DOS-based interface? Too cool!

**my edit** This is gonna be fun. Found the download for VDS-PRO. Surprised VCDS doesn't have functionality to play with the CCM (or even Vagtacho, for that matter). I know my serial port works, because I've used the same laptop in the past to reprogram Motorola HT1000 radios (which require a DOS-based 486 or slower machine).

My only question - what cable should I buy? I'd love to get a Ross-Tech RS232, but I haven't seen any for a while!

More VDS-PRO stuff than you ever wanted to know.
Additional CCM coding and configurations with VDS Pro

Hey, more is better. I did find a KKL-compatible cable last night (like 10 minutes after doing different searches on ebay AND after posting a WTB in this forum's classifieds). I'm eager to start using it.

I presume this is how someone here in Texas programmed my windows to go up/down with the remote on my mk4s?

Yep - that's how I did it.
The "windows up/down with key fob" is a fun party trick I do for people who bring me their Mk4s for some work.

For future readers / reference, here's what the cable looks like:


And yes - has to be serial (no USB doesn't count/work), and it has to be run from a native DOS session. Even doing a "Reboot in MS-DOS" from WinXP doesn't seem to work.

pkhoury said:

Nice, another Paul. That's tempting, except when the car is parked and the alarm on. Or rather, door locks engaged (because seriously, who even pays attention to car alarms anymore?)

Click to expand...

Yes! I forgot, you have to cut the wires to alarm horn under the dash too! LOL!

I rarely lock my doors.

The VDS-PRO mod worked great. Chose controller 46, logged in with 19283, and then read EEPROM (serial). 04352, 04353, and 04354 were all 140. Changed all three to 88 and the rear hatch works like it's supposed to now! No clue how I lived without that feature for 4 years now.

Now I just need to figure out how to do it on my mom's 2005 wagon. It has an electronic switch for the handle, rather than a physical switch like the Golf. On it (which also has a 1C0 CCM), 88 just makes the hatch unlock when the alarm is armed. So I changed it back (default value of 45), and I'm going to read more through that LONG thread.

45 is binary 00101101.

Try changing one of those "1"s to a 0.

00101001: 41
00100101: 37
00001101: 13

Nuje said:

45 is binary 00101101.

Try changing one of those "1"s to a 0.

00101001: 41
00100101: 37
00001101: 13

Click to expand...

I keep forgetting that it's binrary (but I'm just inputting it as a decimal).

Going further down that thread (I believe it was MATT98-AHU who had the post), I saw he used a value of 203 for the Jetta wagon. I haven't done a test drive to see it it automatically rearms the locks when you get over a certain speed, but the trunk hatch now works like it's supposed to.

On the Golf, it did reenable auto locks. I just changed that in VCDS, and my changes from VDS-Pro stuck.

I'll eventually figure this out. I know binary, but I'm rusty on it, as I last used more extensively about 7 years in grad school.

pkhoury said:

I'll eventually figure this out. I know binary, but I'm rusty on it, as I last used more extensively about 7 years in grad school.

Click to expand...

I used it in my Cisco class.
Haven't used it since.
I find it's easier and faster to use Bing to convert it.

The Windows calculator will also give binary value, Programmer setting.

Would any of these tricks work on a 2003 Jetta wagon?

Goal is to make rear hatch accessible when battery is out of car. Installing battery to get hatch open is a pain and time-consuming.

Given that the Jetta wagon hatch has an electric release, I don't see how it'd work.

Works on the Golf because there's a physical / mechanical lever you pull to release the closure.

pkhoury...since deleted said:

...enabled on a relative's 2005 Jetta wagon...works any time the doors are unlocked.

Click to expand...

...but not with the battery out of the car, I bet. (?)

Yep, since the Jetta wagon's "release" is actually an electric switch...

I posted by accident and finally learned how to delete instead of simply edit posts.

I got this thread that I started confused with another about opening the hatch when the doors are unlocked, and replied in the process of closing tabs (I have way too many open).

Well! So I gotta get resourceful. Remove the pin or stud that the latch grabs so it has nothing to fasten to, or just cover the area with a small board so It cannot fully engage.

The release switch has fallen down inside the door card, so that method won't open it—at least until I dare to wrangle with the devious and deceitfui door card…

what wire did you cut to make the trunk never lock? was this for a wagon i have a wagon and want to make it so it never autolocks i just push the electronic button/lever on the trunk and its unlocked and opens how can i do this, id rather re wire then fiddle with software i have vcds so if that works then how?

I would also LOVE to de-commission that $@$! auto-lock feature on my 2005 wagon. What a total PITA.

Problem is, I really don't dare get into programming on my Ross-Tech VAG-COM (which I have). Been far too long out of the programming business.

Is there anybody in the Northeast who could do that for me, like what pkhoury posted above? Honestly, I'm drooling just imagining that if the doors were unlocked, so would the rear hatch!

Ross-Tech software won't work for this anyway, but check out this thread and see if someone who's tried @gmenounos's little app is in your general area. It's only a matter of flipping a few bits in the CCM - I've done it on a few Golfs, and at least three Mk4 wagons using the old (DOS) VDS program.

Thanks, will do. I see where gmenounos is just down the road a piece from me -- maybe I can pay a visit (if the borders are open.....)