Joined
·
49 Posts
Here is a solution for anyone wanting to install trailer wiring. My Pro S was delivered as "Vehicles without trailer preparation", which means that if I wanted to install the VW OEM wiring kit I would need to run a wiring harness to the front of the vehicle and mess with CANbus wiring under the dash. The solution below is much easier to install, but be aware it will not allow coding to auto-adjust stability control, steer assist, etc.
I purchased a Tekonsha 119250 Trailer wiring module. It requires no direct contact with the wires in the car as it uses split-core hall effect current sensors. It works perfectly for me.
Since there is no cutting or splicing this should not void the warranty, and it's not adding any load to the wires, so does not create error codes.
Detailed instructions for the ID.4 Pro S:
Remove the two lower plastic tracks. Three T30 Torx screws at the bottom.
Remove the floorboard.
Remove the scuff plate trim piece by pulling it straight up (clips only, no fasteners).
Remove the one T25 Torx screw inside the cover hinge hole, on both sides. For this kit you will need access to both side panels.
![Hood Automotive tire Vehicle Steering wheel Steering part]()
The side panels can now be pulled back (three metal clips). It can be gently pried back to allow enough access without removing completely.
Unplug the connectors from the power outlet and interior lights to avoid strain on the cables.
![White Product Automotive design Hood Automotive tire]()
Find the wiring bundle that goes into the rear corner lights.
The left side has three wires (Brown, Black/Gray, Black/Red), wrapped in foam-cloth tape. Remove the tape to access the wires.
![Light Gadget Electrical wiring Line Circuit component]()
Black/Gray is the tail light. Attach sensor with Brown sticker.
Black/Red is Left Turn and Brake. Attach sensor with Yellow sticker.
![Automotive design Hood Motor vehicle Automotive lighting Headgear]()
![White Motor vehicle Automotive design Hood Automotive tire]()
The Right side has four wires (Brown, Black/Purple, 2 x Gray/Red), wrapped in foam-cloth tape. Remove the tape to access the wires.
Black/Purple is Right Turn and Brake. Attach sensor with Green sticker.
The wire going to the right side can be conveniently taped with cloth friction tape to mount points for the liftgate sensor wire (under the scuff plate trim).
Sensor with Red sticker is not used and should be secured.
Important: When attaching the sensors make sure the arrow (clip end) is closest/pointing to the lights.
![Motor vehicle Hood Automotive design Trunk Electrical wiring]()
There are two convenient grounding points on the left side of the car. I used one to mount the module and the other for the ground wire.
![Bumper Automotive design Automotive exterior Gas Hood]()
I took power from the 12V "cigarette" outlet in the rear, via a 15A fuse. I made a pigtail jumper/adapter so that no wires need to be cut. These are the plug (1J0919321) and terminals (N90696603) used on the power outlet connector. Another alternative would be to simply run the power wire into a "cigarette" plug, and only plug it in when towing a trailer.
The Tekonsha kit includes some adhesive foam sheets to wrap the sensors. I also wrapped the wires in cloth friction tape from the local hardware store, to prevent rattles and wire chafing.
The module does some calibration on initial power-up, so sometimes it takes a minute to get its act together, but after that it works as expected. The module is supposed to be powered permanently (which can be accomplished by changing Fuse 52 position), but I prefer that it powers down when the car is off.
![Automotive tire Automotive lighting Hood Motor vehicle Automotive design]()
On the left side remove the plastic plug. Feed the 4 pin trailer plug through a new rubber grommet ( 1.75" drill hole size). Insert the rubber grommet.
I purchased a Tekonsha 119250 Trailer wiring module. It requires no direct contact with the wires in the car as it uses split-core hall effect current sensors. It works perfectly for me.
Since there is no cutting or splicing this should not void the warranty, and it's not adding any load to the wires, so does not create error codes.
Detailed instructions for the ID.4 Pro S:
Remove the two lower plastic tracks. Three T30 Torx screws at the bottom.
Remove the floorboard.
Remove the scuff plate trim piece by pulling it straight up (clips only, no fasteners).
Remove the one T25 Torx screw inside the cover hinge hole, on both sides. For this kit you will need access to both side panels.
The side panels can now be pulled back (three metal clips). It can be gently pried back to allow enough access without removing completely.
Unplug the connectors from the power outlet and interior lights to avoid strain on the cables.
Find the wiring bundle that goes into the rear corner lights.
The left side has three wires (Brown, Black/Gray, Black/Red), wrapped in foam-cloth tape. Remove the tape to access the wires.
Black/Gray is the tail light. Attach sensor with Brown sticker.
Black/Red is Left Turn and Brake. Attach sensor with Yellow sticker.
The Right side has four wires (Brown, Black/Purple, 2 x Gray/Red), wrapped in foam-cloth tape. Remove the tape to access the wires.
Black/Purple is Right Turn and Brake. Attach sensor with Green sticker.
The wire going to the right side can be conveniently taped with cloth friction tape to mount points for the liftgate sensor wire (under the scuff plate trim).
Sensor with Red sticker is not used and should be secured.
Important: When attaching the sensors make sure the arrow (clip end) is closest/pointing to the lights.
There are two convenient grounding points on the left side of the car. I used one to mount the module and the other for the ground wire.
I took power from the 12V "cigarette" outlet in the rear, via a 15A fuse. I made a pigtail jumper/adapter so that no wires need to be cut. These are the plug (1J0919321) and terminals (N90696603) used on the power outlet connector. Another alternative would be to simply run the power wire into a "cigarette" plug, and only plug it in when towing a trailer.
The Tekonsha kit includes some adhesive foam sheets to wrap the sensors. I also wrapped the wires in cloth friction tape from the local hardware store, to prevent rattles and wire chafing.
The module does some calibration on initial power-up, so sometimes it takes a minute to get its act together, but after that it works as expected. The module is supposed to be powered permanently (which can be accomplished by changing Fuse 52 position), but I prefer that it powers down when the car is off.
On the left side remove the plastic plug. Feed the 4 pin trailer plug through a new rubber grommet ( 1.75" drill hole size). Insert the rubber grommet.
