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Discussion Starter · #1 ·
Hello PassatWorld!

I've got a strange electrical problem here so hopefully we can figure this one out together. I'm sure other people have had this trunk failure before.

The trunk release button (down by gas tank button on driver side) suddenly stopped working a couple weeks ago.
This button was the only way that I could open the trunk without going in through the backseat to the emergency release handle.
The button has worked every time for over 4 years (since I bought the car).
I do not have a remote to test with, nor do I have a master key (HAA) that will open the trunk.

Keys and Remotes:

I only have the valet key (NAA) for my vehicle (only opens driver door and starts car; doesn't open passenger door or trunk, doesn't lock/unlock valet trunk lock)
** I do not have a remote for the vehicle.... ** (New switchblade key and remote are on order from

Diagnostic Tools:
Klien Digital Multimeter (Auto VDC)
12VDC Power Supply (battery charger set to 2A)

Repair Attempts:

I have replaced the physical trunk release button, that sits down by the gas button FD side (purchased from VW dealership ~ $70 bucks).
This did not have any effect on problem.

I then removed the trunk lid liner to monitor the two conductor (solid brown & solid blue ) connector to the trunk latch actuator or whatever it's called, P# 3B5 827 061C.

The following tests were done while the car was running, with the trunk open, and with the trunk latch manually pushed closed (locked state as if trunk was closed). Tests always begin with the aforementioned conditions.
1) I activate the trunk release button: no change in VDC (stays at 1mV ie no draw,) trunk doesn't open.
2) I activate the trunk key microswitch by clicking it in with my finger (mimicking the key turning in the lock): no change in VDC, trunk doesn't open.
3) I physically activate the emergency trunk release handle: trunk latch releases, audible beep and visual door open icon and visual "LUGGAGE COMP. OPEN" display on dash, trunk opens.
4) I momentarily apply 12VDC power to the 2 pins of the trunk lock actuator with my power supply: actuator fires, trunk latch releases, audible beep and visual door open icon and visual "LUGGAGE COMP. OPEN" display on dash, trunk opens.

So I know that my trunk latch actuator works, and I'm assuming that the trunk release button works (assuming the new VW part wasn't bad... original part prob wasn't bad either).

What am I missing here......
I have been searching through post after post and the only other thing that seems to be involved with this issue is relay 2 on the 13 pos. relay plate (Relay for remote unlocking motor Rear lid):
Parasitic Drain and Relay for Remote Unlocking Motor Rear Lid

Fuse #14 is fine.
Is there anything besides relay 2 that could cause the trunk to not open?
How do I diagnose this relay?
Are there any other relays in the car that are the same as relay 2, so that I can swap relays and see if the trunk opens?
The VW dealership also replaced my CCM module 3 years ago, so the CCM should be fine to signal the trunk.
I don't understand why it would just suddenly stop working...
My gas cover release button that is beside the trunk release button works fine.

Thank you all in advance :bowdown:

10,466 Posts
It could be a faulty trunk unlock relay, you could try the start inhibitor relay from pos 13,
make sure both relays have the same terminal numbers (30,85,86,87,87a).
Note: The engine won't crank with relay 13 removed.

But it is more likely there is a bad connection at the CCM or "A" Pillar; or a corroded splice in the harness between.
It could also be a fault in the wiring into the door.
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