[probmxstyle]

I am trying to figure out if my 2021 45e has factory trailer prep wiring. I don’t see the 8SL option for my VIN but I have this loose 8 pin connector next to the battery. Anyone know what it’s for? Thanks

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[jad03060]

If you have the towing package for the G05, there is a 4-pin socket under the dash next to the driver’s left knee to install an electronic brake controller.

In 2021, for USA customers on the G05, BMW did not include a towing makeready, while that was available in some other markets. I’m guessing, but that probably included the wiring to plug in the electrical interface to make the trailer lights and stability control stuff work. Don’t know what that socket was used for. BMW typically does not include ‘extra’ plugs for options, but one it did, at least in the USA where it wasn’t standard, was Sirius radio.

[probmxstyle]

Originally Posted by jad03060

If you have the towing package for the G05, there is a 4-pin socket under the dash next to the driver’s left knee to install an electronic brake controller.

In 2021, for USA customers on the G05, BMW did not include a towing makeready, while that was available in some other markets. I’m guessing, but that probably included the wiring to plug in the electrical interface to make the trailer lights and stability control stuff work. Don’t know what that socket was used for. BMW typically does not include ‘extra’ plugs for options, but one it did, at least in the USA where it wasn’t standard, was Sirius radio.

Would this be it? Found it hanging by the brake pedal. If it is, that’s strange since I have a ‘21 without the 8SL option listed.

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[TurtleBoy]

Originally Posted by probmxstyle

Would this be it? Found it hanging by the brake pedal. If it is, that’s strange since I have a ‘21 without the 8SL option listed.

I think they may have been all pre-wired back then.

[probmxstyle]

If my car has the pre-wiring, are these the parts needed to finish the job?

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[jad03060]

I thought the G05 as sold in the USA did not come with the towing pre-wire at all except maybe for the first year or so…the previous X5 generation sold in the US did come prewired. You can tell from the VIN decoder what’s in your vehicle. But, yes, I think that’s the socket for the electronic brake controller. I’ve not torn mine apart enough to tell you if that’s the 8-pin plug for the electronics module for the trailer lights.

My 2021 had the towing option so did not have the make-ready.

[TurtleBoy]

Originally Posted by probmxstyle

If my car has the pre-wiring, are these the parts needed to finish the job?

Hopefully someone can verify that wiring and answer about parts. I think there may be a thread or two discussing retrofitting the OEM hitch. Maybe try a few searches.

[probmxstyle]

Originally Posted by jad03060

I thought the G05 as sold in the USA did not come with the towing pre-wire at all except maybe for the first year or so…the previous X5 generation sold in the US did come prewired. You can tell from the VIN decoder what’s in your vehicle. But, yes, I think that’s the socket for the electronic brake controller. I’ve not torn mine apart enough to tell you if that’s the 8-pin plug for the electronics module for the trailer lights.

My 2021 had the towing option so did not have the make-ready.

The vin decoder says nothing about the 8SL option for my car, which is why I am confused. I looked again and the plug and wire colors look just like the pre-wiring option.

[djohn]

Take a look at this video: https://g05.bimmerpost.com/forums/sh...1#post26809737

Specifically, the connector shown at 1:40. It is 8-pin, but it's not by the battery, but rather over on the right. I would think you'd have this one too, since you have the connector that's up front.

I don't know details about parts needed, though.

[probmxstyle]

Originally Posted by djohn

Take a look at this video: https://g05.bimmerpost.com/forums/sh...1#post26809737

Specifically, the connector shown at 1:40. It is 8-pin, but it's not by the battery, but rather over on the right. I would think you'd have this one too, since you have the connector that's up front.

I don't know details about parts needed, though.

Yeah, that is where the wire is. But my battery is also down in that corner as well. Maybe its a 45e thing.

[djohn]

Yeah, or possibly you have primary and secondary 12V batteries both in the rear. A 45e thing.

[benaj]

I can verify that there were at least some X5's produced in 2021 without 8SL option listed on VIN decoders but still had the factory pre-wiring done.

Our March '21 production X5 xDrive40i is one of those odd-balls. No mention of 8SL on VIN decoders but luckily I found ours factory pre-wired when I pulled apart panels to check. I did the combo of Stealth hitch hardware but with the full BMW factory towing electric retrofit.

To answer probmxstyle's question about parts needed for full factory retrofit for those X5's that came pre-wired, his included screen shot is almost complete. You will also need the rear lower bumper finishing trim with cutout for the factory hitch (body shop will need to paint to body color) and IIRC a lower bumper reinforcement bracket. There are some other threads here that will detail this info, will need to search.

The official BMW trailer hitch retrofit instructions are also very helpful:
https://rparts-sites.s3.amazonaws.co...STRUCTIONS.PDF

[jad03060]

Many of the parts produced for the vehicles are customized specifically for their assortment of options unlike many vehicles of old that came with the same harness, but may have numerous empty sockets unless that option was installed…BMW generally doesn’t do that. It may be that they had some harnesses from maybe the previous model year made for the towing option where it was ‘standard’. Once those got used up, it no longer was included. The factory itself, while it does make some things on site, is more of an assembly line versus a manufacturer of all the parts…the factory makes and paints the body and maybe the engine, but many of the other parts come from other vendors, or other BMW factories.

If you do have the towing make ready, it’s much easier to obtain the full OEM capabilities. Getting the trailer lights to work isn’t that hard, but there’s lots more to the make ready and full towing package than just the lights.

[probmxstyle]

Originally Posted by benaj

I can verify that there were at least some X5's produced in 2021 without 8SL option listed on VIN decoders but still had the factory pre-wiring done.

Our March '21 production X5 xDrive40i is one of those odd-balls. No mention of 8SL on VIN decoders but luckily I found ours factory pre-wired when I pulled apart panels to check. I did the combo of Stealth hitch hardware but with the full BMW factory towing electric retrofit.

To answer probmxstyle's question about parts needed for full factory retrofit for those X5's that came pre-wired, his included screen shot is almost complete. You will also need the rear lower bumper finishing trim with cutout for the factory hitch (body shop will need to paint to body color) and IIRC a lower bumper reinforcement bracket. There are some other threads here that will detail this info, will need to search.

The official BMW trailer hitch retrofit instructions are also very helpful:
https://rparts-sites.s3.amazonaws.co...STRUCTIONS.PDF

Thanks for the confirmation these odd-balls exist. I actually think I am going to go with the Stealth Hitch and BMW retrofit as well. How was the install? Did you have to code it after?

[BlkGS]

Originally Posted by benaj

I can verify that there were at least some X5's produced in 2021 without 8SL option listed on VIN decoders but still had the factory pre-wiring done.

Our March '21 production X5 xDrive40i is one of those odd-balls. No mention of 8SL on VIN decoders but luckily I found ours factory pre-wired when I pulled apart panels to check. I did the combo of Stealth hitch hardware but with the full BMW factory towing electric retrofit.

To answer probmxstyle's question about parts needed for full factory retrofit for those X5's that came pre-wired, his included screen shot is almost complete. You will also need the rear lower bumper finishing trim with cutout for the factory hitch (body shop will need to paint to body color) and IIRC a lower bumper reinforcement bracket. There are some other threads here that will detail this info, will need to search.

The official BMW trailer hitch retrofit instructions are also very helpful:
https://rparts-sites.s3.amazonaws.co...STRUCTIONS.PDF

How far up there was your harness? I dropped the panel real quick and didn't see anything obvious, but I didn't really get to see behind the knee airbag.

[probmxstyle]

Originally Posted by BlkGS

How far up there was your harness? I dropped the panel real quick and didn't see anything obvious, but I didn't really get to see behind the knee airbag.

My 4-prong was tucked up next to some wires to the left of the brake pedal. You can also look in the back of the car, on the passengerside, behind the removable side cover. Mine has a 8-pin harness down next to the 12 v battery.

[BlkGS]

Originally Posted by probmxstyle

My 4-prong was tucked up next to some wires to the left of the brake pedal. You can also look in the back of the car, on the passengerside, behind the removable side cover. Mine has a 8-pin harness down next to the 12 v battery.

I guess I'm one of the unlucky ones that has a 21 without the trailer wiring. Bummer.