Hello folks. Very similar problem with mine by the sound of things. Checked the wires and all look good so I'm thinking it must be something inside the handle unit itself (maybe wrong) if I was too buy a new handle unit would it just plug in and play so to speak. (No mapping required or anything too technical?) cheers
I have never replaced a rear hatch solenoid, but no, that job will not involve any re-coding etc, it is just a electro mechanical device you are replacing.
Okay, I thought that I had posted today via my iPhone, but it appears not!
So, first of all, main fuse box layout as I can't see your pictures, For a 2009/2010 car looking at the fuse box in the car and starting with the groups of MINI fuses, top row of mini fuses are 1 > 8 reading left to right, middle row of mini fuses are 9 > 16 reading left to right, bottom row of mini fuses are 17 > 24 reading left to right. Next groups of ATO fuses, top row of ato fuse are 25 > 41 reading left to right and bottom row of ato fuse are 42 > 58 reading left to right.
Edit:- 45 is GREEN 30 Amp (manual quotes yellow 20 Amp) 48 is WHITE 25 Amp (manual quotes BLUE 15 Amp)
Another Edit:- my daughter has owned that car from new, so that car agrees with your one also owned from new by you, other "errors" are 18 is BROWN 7.5 Amp (manual quotes BEIGE 5 Amp), 20 is YELLOW 20 Amp (manual quotes BLUE 15 Amp), 22 is BLUE 15 Amp (manual quotes BEIGE 5 Amp), 23 is RED 10 Amps (manual quotes BROWN 7.5 Amp), 24 is BEIGE 5 Amp (manual quotes RED 7.5 Amp), 29 is BLUE 15 Amp (manual quotes YELLOW 20 Amp), 32 is RED 10 Amp (manual quotes BLUE 15 Amp) - listed as diesel engine controller, but this car has a petrol engine!
So, you can't believe much of what SEAT commit to print in their owners manuals, no better for VW, wife's August 2015 Polo has very few fuses covered by the owner's manual - for others "talk to dealer" - idiots!
Anyway, so I think that you should now ignore any "wrong" fuses that you find and maybe try using the search function on this forum as there has been, in the last few months, been a few threads on this very problem. Roughly speaking you have about or at least three fault "options" in no real order:- (1) broken wire where the wire pass out of the car into the hatch (2) a failed locking unit in the hatch (3) water ingress into the plug<>socket on the power supply to the locking unit. I'd think that the hatch rear trim needs to come off, that can be a nasty job so take care to minimise any breakages to the rear trim panel.
For some unknown, but clever reason, when I started chasing this battery discharging problem, I too took pictures of the exposed fuse box, found a drawing of the fuse locations by numbers, printed that off and created a table of fuses - types, rating and function from the owner's handbook, then compared that to the actual fuse box into that car - before starting to selectively remove fuses to try to eliminate where the battery drain was coming from.
Back to your problem:- if you connected a voltmeter across the pins of the locking unit that actually operate the release - I can't say more as I have not studied that part of that car - if you operate either lock/unlock of the hatch from the internal switch or the key fob, you should only see a quick change in value as it will only be pulse and not a steady hard 12V . typically any wire breakage will be within the rubber convoluted protector that covers the wiring as it transitions from the car's main body into the hatch area. Maybe try to firmly manipulate that soft rubber to see if you can feel any unusual, like a chopped section of wire, I have only had this problem once and it was in a Ford Fiesta and it was obvious when I squeezed etc the soft rubber wiring harness protector, well maybe I've found that one other time on my mates old SAAB 9-5 same easy bit of fault finding. Now if you do find this, you will then need to try to pull that wire back through into the hatch area, splice a new length of suitably rated wire onto it including heat shrink protection against it shorting out, then using something like a stiff length of thinnish wire as a fish, push that stiff length of wire back along through the soft rubber protector making sure that you do not damage it, and into the main car area. Remove any plastic panelling you need to and pull the new section of wire back through into the main car body while making sure that the actual repair point is still located in the hatch. Locate the other end of that chopped wire and pull it make through into the main car body, splice it to the new section of wire adding heatshrink for protection - job done! I would always make sure that any joins are kept away from the area being flexed - just makes for good sense. Now check that there are no more damaged or chopped wires. Of cource it could be that it only the locking unit that is faulty - can you manipulate the locking elements to make sure that nothing has seized?