a4 Wagon Rear Hatch Electric Actuator Is Always Active

[ninedee_golf_tdi]

An 03 wagon's rear hatch always opens simply by touching the pressure switch under the key hole and the hatch is unable to be locked. Is this issue within the rear hatch ? Faulty lock mechanism ? A gremlin fuse on another circuit ? The hatch switch in the drivers door is known good. Thanks for any guesses.

 

[csstevej]

I would check power at the actuator….if it’s momentarily on then off it will be the actuator. If it’s on constantly then I believe there’s a relay for that …just my .02

 

[irvingj]

I'd look more closely at the door switch -- perhaps it's "actuated" all the time?

My understanding of how the rear gate lock works is that it's a 2-step process:
1) Arm the system (on my 2005, I don't hear any noise at all, like a relay) by either lifting the door switch up or pushing the rear gate button on the key fob;
2) Then lift up on the pressure switch to activate the lock's release solenoid. (You have about 15 seconds to do this before the system automatically de-arms)

If all you have to do is lift on the pressure switch, the system is being constantly "armed" which I believe occurs within the ECU. I don't know for sure, but I suspect the door switch is normally open; I'd check that to see if it's staying closed permanently. Maybe even the key fob?

 

[ninedee_golf_tdi]

Some answers are stranger than the original problem. I spent hours studying the wiring diagrams, disconnecting this and that, swapping parts from my other wagon, and nothing solved this issue. It was like everything was working correctly, except it wasn't. I was going to order new keys and to make sure I ordered keys for this car, I locked the drivers door with the key which activated the alarm, then unlocked it.... and sure enough, the rear lid works like it should. I guess something in the ccm got confused and kept the rear lid pressure switch active. I can not now duplicate the problem. Weird.

 

[Nuje]

More than one weird electronic issue I've come across has been solved by disconnecting the battery cables, holding them together (obviously away from the terminals) to fully discharge everything, then hooking the cables back to the terminals. So, I'm guessing you had something similar that needed a metaphorical butt-kick to get its head on straight again.

Thanks for coming back and posting the "solution", such as it was.