Retrofit Keyless Entry

[Pliind]

The short version: There is not one cable there

You have to do all the wiring in the car, from the A and B pillars on both sides of the vehicle to the CEM. 3 cables per B-pillar, 1 cable per A-pillar and 2 cables for the antenna in the trunk. Everywhere (except in the trunk) you have to fight your way through to the door with the cable (I'm currently stuck there) - in the door you also have to build the wiring harness yourself. 3 cables for the lighting and ground of the door handle to the door control unit and the aforementioned 1 cable that goes to the CEM. In the rear doors there are 2 more cables for the keyless go antennas. You have to build everything yourself, there is not 1cm of cable. Or replace the complete wiring harness and buy it from Volvo, that's the craziness I'm talking about. The cables that have to run to the CEM get tangled up in the central wiring harness in the interior, so you have to replace the entire vehicle wiring harness.

You can't get wiring diagrams anywhere except in VIDA, which unfortunately is not currently available to me in Germany. Haynes Pro and Workshopdata both have no information about the new Volvo SPA vehicles ...

My honest estimate of the difficulty: 10/10
- remove complete interior
- most likely the removal of the dashboard
- Build wiring harnesses yourself
- Obtain all plugs and pins
- no wiring diagrams

It is much appreciated that you wrote all information, but it feels it still lacks precision.
1. You are talking about the plug and a dificulty with it. Which plug? There are plenty of those.
 - Are you having trouble leading the plug from the handle in front door through the rubber hose connecting the door and the pillar?
 - or are you having a problem disconnecting the plug from CEM in order to add the wires? Are you having a problem taking out the CEM module?
   https://www.youtube.com/watch?v=_ladh-yLyXM
2. Which volvo model are you talking about. Altohoug they all look similiar - they might be differences.
3. One picture says same as 1000 words. 
4. Of course there are wiring schematics available. Christmas came early this year:
    https://static.nhtsa.gov/odi/tsbs/2023/M...6-9999.pdf 
5. CEM requires 10 new wires into two plugs - 4 single ones for 4 handles and 3 double ones (so 6 in total) for anntennas in 2xback doors L+R + 1 antenna in the trunk. Handles operate on 1 wire, antennas on 2. If you want LEDs to be enables - all you do is in each door itself.

I think it might be wise for me to perhaps divide the project into 2 peices, first is just to get the handles swapped and LED's working, and then later on when perhaps you or somebody else has more info / pictures/ links to how to actually connect the antenna/signal cables to the cem-plugs then take on the keyless part of the project.

Would you recommend just buying 4x cheap harnesses for backdoors and just extracting the handle-plugs with pins or do you have links to connectors and pins that would enable me to build these harness peices myself?

In my head it is basicly per door 1 plug, 3 wires (where 1 will be unused for first part) and 2 connectors that can slide into my current harness.

(and im sorry for badgering you, i know you are going to post when your done but i think this project is super exciting and i'm climbing on my walls trying to find answers myself while i wait )