History
A 2017 184 tdi ST car with 60k miles, only mod is a front dash camera. It did park the mirrors one day about 2 months ago, odd dead “radio” screen but last one was over a year ago, never updated GPS maps etc. One Monday morning after a wet weekend with moisture/damp around (2-3C) it started with “Wiper Fault” and “stop start not available” on dash. The rear windscreen washer and washer still worked but front wipers and washers did not. That night I checked the bonnet switch. I pulled fuses and then wiper started to work again. The next day it worked but at end of 25 mile trip the wipers kept working even though car was locked and stalk in off position, so I pulled random 30A fuses under bonnet until wipers stopped and then replaced fuse when I wanted to drive again, at which point it stopped working again. I then checked the washer pump (thinking maybe a shorted pump would kill J518 controller) but found only one pump which worked for rear washer so that was pointless check. So then pulled the Wiper motor.Bonnet switch
There is a connector/plug between the RHD drivers/RH headlight (so look left when standing at bonnet) and radiator. It has a corrugated protection cover. Mounted to a clip on radiator side. Ignore the other connector that is not corrugated covered and is loose. The circuit is open when bonnet is closed, so unplugging it here will bypass it. The dash image shows bonnet is red when it is up. There might be a rule that windscreen wiper will not work if bonnet is open (e.g switch faulty) and speed is under 8 kph.Fuse
Fuse 19 for the wipers is 30A Green, on my car, under bonnet, on right as you look from front, the 4th fuse on right counting towards the windscreen, the first 30A fuse. Some Youtube video showed it to be last fuse at back on right on a car which is wrong for my car. I have no “fuse plan” anywhere to tell me which fuse 19 is in this engine bay fuse box!!! See here for plan https://fuse-box.info/seat/seat-leon-mk3-5f-2013-2018-fuses - I am going to print this out and put it in the car! The user manual just lists the fuse location, rating and number but there is no picture plan, it also shows the cabin fuses to be behind a LHD steering wheel when in fact they are behind the glove box on RHD. The car has not been messed with (I bought it as second owner at 3 months) so there is no missing paper sheet I think or missing sticker. When you replace a fuse, remember to look down and make sure it is a slot with both grippers for the fuse legs as there is one nearer the front with one gripper that I mistakenly replace the fuse into which did confuse things.VCDS
Need HEX-V2 as CAN-Bus car, bought for this job from Grendan.co.uk for £220 for 3 VINS/cars. If you go into Steering Wheel controller you can check the wiper stalk outputs. They do not show on the Central Controller outputs. One of the rain sensor input goes from Active to “0” as wiper stalk moves out of intermittent. You can also "tell" it to cycle wipers/washers etc.Faults after clearing
= 4720 comms on Engine
= 8304 comms on ABS
= 947204 comms to wiper on 09 Cent Elect (J519)
Module 09 is for wiper – no comms, not “Active” so cannot see any output to motor in software.
Windscreen washer
The windscreen washer does front and rear with 2 wires and only one pump on the reservoir so must spin one way for rear and other way for front, in my case it still worked on rear. Need to remove the lower front wheel arch liner on left hand side (passenger for RHD) to get to it.Front windscreen wiper motor
To get to wiper motor, remove plastic cover between windscreen and bonnet. Ease up the polystyrene blocks at wings/fenders to pull a plastic pin each side, then remove about 3-4 steel U clips at the front edge. Then mark position of end of wipers with tape on windscreen. Prise off the plastic caps from end where groove is, undo the 13mm nuts. Apply penetrating oil spray to spindle shafts and wait. You WILL need a windscreen arm puller, the driver’s side is easy, the middle/passenger side one has a big lump of the plastic trim, so when it is parked it is very hard to access at the front with a 2 arm puller; ideally if the motor is working you should put it in Service mode so the wiper are vertical on windscreen but my motor was not working. Official VAG puller is a tube with a slot in it so you can come from rear/back and miss the plastic but I had a 2 leg puller with a cone to hold the legs in which is quite bulky. I ended up pulling the plastic trim off while the arm was still bolted to give a bit more room and then using my puller at 70 degrees (so not properly square) to miss the plastic trim. The plastic trim has the bonnet wiring attached via a clip which you can only get to after it is free (needs pliers), I left this attached and just move cover to gain access to the motor. The motor plug clip is on under side, I removed motor assembly 3 Torx mounting bolts, worked it past wiring loom at front and took whole assembly out to get to the plug more easily. My wiper wiring is obvious if you look at the wiring, large/thick wire in red/white on pin 1 from fuse 19 (green 30A under bonnet), large/thick wire in brown to earth on pin 2, small/thin wire to pin 4 from LIN Controller. To check wiring need to use a 21W brake light bulb or similar on pin 1 to 2 to ensure it can provide reasonable power (a nearly broken wire can provide 12V at 0A but will not light the bulb pulling about 2A). The wiper is a “smart” device on LIN bus, so it has power/earth/control wires. LIN bus uses 12V on control wire not 5V which is CAN bus voltages. Measured from earth control wire seemed to be at 11.1 Vdc, 250-270 Hertz on Vdc and 320-330 Hz on Vac (frequency registering on Fluke 179 RMS Multimeter), 3.7-3.8 Vac with engine running and wiper stalk on. Looking on ebay the pre facelift cars had a different Bosch number so I stayed safe and got the same Bosch number regardless of the Seat part number. Worth a £16 gamble to see if that is what it is wrong but no way to test the wiper and £240 for a new one. The bus line wire is hard to check as it cannot draw a lot of power, wire breaks on way back to the J519 controller (by fuse box in cabin) happened here even though multi meter results looked good.J519 Central electrics / BCD.
On RHD car this is on passenger A pillar. To get to it, remove end of dash, base of rear seat, plastic between top of rear seat and door (plastic clips under seat base) at base at least. Remove bonnet release handle – there is a C clip that you need to pull forward (like old window winder handles) then it will pull off. Then remove cover, plastic screw and plug that is revealed. Now ease sill cover from base of B pillar and pull it up from sill. Remove sill cover past passenger seat belt. Remove horizontal trim over passenger’s feet – unplug light. Ease glovebox sides to drop it into lowered position, unclip the lower black switch that is revealed. Remove cover to Map CD player (pulls forward). Remove glovebox (3 screws top, 3 screws bottom + 2 at back in bigger Torx for CD player. Unclip the fir tree connector that holds the wires to the CD player to allow glove box to sit in footwell. Now look at inside of A pillar, you will see the back of the J519 with 3 multi core wires going up to the other side in a dark hole. Reach into gap, starting at the rear plug, there is a small clip to push down to allow the locking handle to undo. Remove all 3 multi plugs. I did not pull J519 but it has 2 clips at the bottom, but looks like it might have to go backwards past the fuses. To replace, start at the front multi-plug. There is a white guide for the middle plug that you slot the plug into and it rides up into the socket. Rear plug is hardest but look at it from the fuse box side to get the angle right to help you.New LIN-Bus wire.
So I made a short test harness up with an old plug from my used wiper as they had just cut the wiring loom. I fed power from battery via a fuseholder and earth from battery, The Can-Bus wire was soldered into onto pin 30 wire (without cutting wire) then replugged into the J519. The wiper then worked perfectly and all fault codes went (unplugged bonnet switch so wipers worked). So I had to split the middle multi plug to remove pin 30 with the green/white thin wire – cut off the tie wrap for wiring then there are 2 clips and 2 holders side by side. The small wired receptacles you can use a small screwdriver to release (I have correct forked tool), but you need to release it 2-3 times as it drops into the next recess internally as you pull from the rear. I then ran a new wire. So over the passenger’s feet in the engine compartment, unbolt the cover to heating air intake, then 3 nuts to remove the grille to the heating air intake. From inside you can push a finger through at top of heating box and feed a wire through. Then follow the wires across to wiper. I left this wire coming out the top of the heating grille when I bolted it back. I cut the bus wire at wiper and soldered the new wire on with heat shrink. At the J519 end I had the right crimp to do it from fitting my cruise control but I could have just cut it short and soldered it. Then cable tied all wire.So it all works again using an old connector I already had, bit of wire and a crimp I had, took me a week as I had to buy VCDS and old wiper.
