Locked Out
Monday, August 28th, 2023I decided to wash the Ibiza, and found the hatch wouldn’t open.
Like many VAG cars, the 6J Ibiza has a hatch release which is electronic and can be released by a button on the key, by the handle (which is just a switch), or via the diagnostics.
The first two didn’t work, so out with VCDS.
1 Fault Found:
00329 - Control Circuit for Unlocking Rear Lid
011 - Open Circuit - Intermittent
Freeze Frame:
Fault Status: 00101011
Fault Priority: 2
Fault Frequency: 11
Reset counter: 168
Mileage: 50565 km
Time Indication: 0
Date: 2017.11.14
Time: 12:00:55
[Note: Dates on VAG control modules are usually wildly inaccurate]
and surely enough, an output test on the release produced a very quiet click from near the fusebox, but nothing else.
Looking at measuring blocks for the Central Electric Module, the switch in the handle works OK- this box (highlighted in red, measuring blocks channel 8) shows “Activated” if you pull the handle:
Of course, you could just check this with a multimeter or test lamp, but this does have the advantage of checking the whole circuit up to the CEM, and by balancing the laptop where it can be seen, this only needs one person.
So now there’s the possibility of a broken wire or connection, maybe a fuse blown, or a failed release. A check of the manual reveals there’s no seperate fuse for the tailgate, so that rules that out.
To get the tailgate open, you have to crawl into the back of the car (it’s an SC, so no rear doors), folding the rear seats, climb over them, and release it from inside by sliding something flat, like the key, from right to left in a slot in the boot trim, so I did that, removed the boot trim (two T25 screws and a good pull (and who doesn’t like a good pull?)) and got a multimeter on the cable. Operating the boot handle gave a pulse here, so it looks like the release itself is faulty. Happily, I also have the XZN spline bit needed to unbolt it.
The OE part is £30-something, plus carriage, and a pattern part is £22 delivered next day, so as this isn’t a terribly critical part, I got the pattern one.
Which didn’t fix the issue.
A bit of research took me here, and it seems likely there is a intermittent connection in the tailgate, one that irritatingly remade itself, then failed, repetitively.
The connections to the latch are simple: one ground, two switches (one so the car can tell if the tailgate is open, and one for the boot light), and one drive to the release motor.
The green cable is what we want. It starts at the Central Electric Module, has a joint in the boot, then another in the tailgate. Putting a meter on it showed 5 volts: this is how the diagnostics detect the open circuit. Triggering the latch release pushes this up to 12v to drive the motor.
Here’s an important lesson when using a multimeter that I learnt years ago: a meter is really high impedance, so even a poor connection can show 12v when off-load, and this proved to be the case here. I did consider making a test lamp with a sidelight bulb to give it a load, but in the end, I just pulled the wires out of the block, and joined them with solder and heatshrink tubing (easier said than done with a small soldering iron outdoors). The cable wasn’t broken, it was an issue with the connector- probably oxidation.
That done, all the error codes go away, the tailgate release works again, and it’s just a case of putting the trim back together.