Activating Auto, Coming Home & Leaving Home Lights - a walkthrough

[Fatbloke]

This applies to facelift models with rain & light sensor already fitted.

Parts needed:

Auto light switch: 1Z0 941 431 J REH. This is the skoda part, VW variants will work but don't light up green and have a round rather than elliptical so there is a small gap above it when fitted. ~£14 e-bay to ~£65 OEM

2 x repair wires: 000 979 009 E £2.51 each usually in stock at VAG garages.

Access to VCDS for coding is required.

Method:

Remove your existing light switch. With it in the 0 position push the knob in and turn to the right approx. 15 degrees and pull gently back. The switch will slide out of its housing. Disconnect the cable by pressing the locking tab and sliding off the plug. Check whether you have 9 wires going to the plug or 10. If 9 you need to install the extra wire, if 10 go to installing the new switch (assuming the other end is connected).

Remove the pieces of trim from either side of the steering wheel, these lever up from below then pull out. Remove the end panel of the dash as if accessing the fuse box. There is a notch near the bottom to lever it up.

You now remove 5 six point Torx type screws. 2 on the top edge of the panel revealed when removing trim. 2 on the bottom edge of the panel and 1 on the end. You can now remove the panel below the steering wheel and lower it down. The OBD port is secured in the bottom of this panel and can be unclipped and removed if you want the panel out of the way.

Slide out the fibre panel that makes up the bottom of the dash.

Facing you, mounted horizontally, is the CECM with 3 large plugs mounted on the underside. You want Plug A, the black one, furthest left as you look at it. It dismounts by releasing the white lever.

To dismantle the plug you release the tape/clip securing the cable to the housing then ease the housing open and slide out the core of the plug that has 52 connections! The core is 2 pieces that slide apart along along its length so you can identify pin 20. Slide the repair wire connector into the hole with the locking tab on the metal connector facing outwards.

Reassemble the plug and secure the cables to the plug housing then refit the plug in the unit.

The procedure for the switch plug is similar but easier inserting the second repair wire in pin 2 and route it to an appropriate place to join the 2 cables. Cut them to a suitable length and join them, ideally by soldering and insulating with heat shrink sleeving.

Refit the fibre panel, the knee panel, the end panel and the two pieces of trim. Connect the new switch and insert in the housing.

Coding

Byte 12: Bit 0. Coming home timer start - ticked for door opening (my choice)

Bit 2. Coming Home Mode. Unticked for automatic

Byte 17: Bit 3. Coming home via fog lights - ticked (my choice)

Bit 4. Assistance Driving Light (ADL) active - ticked

Bit 5. Coming Home (CH) active - ticked

Bit 6. Leaving home (LH) active - ticked

Job done!