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motoman49, have you had luck with part #PT219-48101-TC ? Also, I'm having trouble locating the additional wiring harness 17-82180. Did you buy yours at the dealer or source it elsewhere?
A few inquired about the location of the converter and pigtail swap, it is the Driver side rear section of the vehicle.
The Converter plug is plug and play, there should not be one there with no towing package, simply remove cap and plug in the new relay. To the farther REAR side of the vehicle in the same area, is the the wire 16-XXXX that need to be swapped with 17-XXXX. You will see the plug when you remove the panel. Please look at pics above for reference to swap out the pigtail and let me know if anyone has a question. Thanks!
Are there any plug and play break controllers for our RX? My Jeep had a factory plug by driver side to plug in the break controller so wondering if RX has same. Thanks
I wanted to offer this to the group. Thanks to KVA for the writeup. I wouldn't have known what to do to accomplish this without it. I have a 2018 RX35L with NO TOW PREP (bench seat). I bought the hitch receiver and trailer wiring adapter/pigtail that is easily available online. I chose the Lexus tow receiver as it looks best IMO. I also purchased the notched valance that replaces the stock under valance (cutout for the hitch receiver). I found that the fuse (30A) was already installed in the appropriate position so I did not need to add. I had some confusion around part #s from KVA's post so I wanted to offer these in case it helped someone. The replacement parking/backup luggage area sensor wire harness is part #82182-48170. Apparently there are a few of these harnesses and each has a different part # depending on what options you have (backup warning/assist, etc.). The part description is WIRE, LUGGAGE ROOM. The tow converter module I ordered was Denso Control Module OEM part #LA061800-1330 off eBay. It's blue and made for the Highlander of the same model year I believe. I had a local body shop pull the bumper cover off to install the replacement wire harness. I installed the hitch receiver myself. I plugged in the tow converter module and connected the trailer pigtail to the replacement wire harness that was installed at the body shop and TADA!!!!!.... worked like a charm.
I wanted to share nome knowledge that may be helpful related to towing with the RX350L. I purchased a 2020 RX350L on 7/1, this is my 4th RX now and my last one (2017), had the towing prep. At the time of sale, I was interested in obtaining the towing prep and as most have shared, I couldn't find one with the options and color combo I wanted. During the final sale, I enquired about the towing capacity without the prep, I was told 2K without, 3500 with. Well, I went home, researched this forum and confirmed the manual recommends 0 lbs without the tow prep and if one orders the 350L with the bench, its not possible to build one with the towing prep from the factory.
In disbelief that 0 lbs was realistic, I started my research journey too confirm and explore the differences and entertain aftermarket install for tow prep (assumption was that it most likely would be cost prohibitive, I wanted to find out nevertheless).
I have some great surprises to share, here is a summary of what I have found:
Radiator - I checked the radiator on the new car lot for a 2020 RX 350L with tow prep. The radiator model # is the same as mine, (31A4). Additionally, I checked Lexus parts and there is only one available for the 2020 RX350L with no tow prep and it is the one WITH the same model #. Conclusion - HD Radiator is installed in my 2020 RX350L with NO tow prep.
Transmission "COOLER ASSEMBLY, OIL" - I checked Lexus Parts and there is only 1 available, I checked my vehicle and it is installed. I traced the bottom hoses of the radiator over to the cooler located by the right front passenger tire to validate the presence. A Lexus Service Tech also confirmed the presence of my cooler and confirmed that there is only ONE type to order.... Conclusion - Transmission Engine Oil cooler for tow prep installed in my 2020 RX350L with NO tow prep.
At this point I start to think.. Perhaps with the key engine components of the tow prep installed, the cost of the tow prep is only $265, I always thought was an extremely good cost for the all of the components offered in addition to the wiring..it is right? Perhaps in recent models all of the components where actually added..possibly not here...?What started to make mores sense at least for the 350L is that possibly the only main difference is in the trailer prep wiring. I go back back to the lot and confirm 2 things.
2020 RX350L on the lot WITH tow prep as a "converter" installed (assumed) in the left hand side of the back driver side wheel well. I took a picture of it. (Mine is missing of course)
2020 RX350L on the lot comes with the factory prepped tow harness wire plugged (assumed).
2020 RX350L on the lot has a "pigtail" part #17 - 8218 that splits out to a harness connecter and plugs into a sensor . My pigtail is #16-82180, plugs into sensor and DOES not have the tow wiring harness coming off it.
2020 RX350L on the lot WITH tow prep has the same alternator as mine and there is only 1 available to order. Conclusion - SAME alternator..
After looking at numerous schematics, wiring diagrams and tech material of which I am happy to share, here is my conclusion and result with respect to the wiring harness. There only 2 PARTS needed to replicate the WIRING factory trailer tow prep:
I installed #17-82180. After that is installed, I installed my previous wiring towing harness I bought for my last RX350 with tow prep that connected to the prior factory wiring harness...same plug works!
I installed from Lexus Part# 81985-YY020 (Actually stamped Toyota on it), RELAY tow converter
I installed and tested - ALL GOOD!! So, I know I now have the wiring of what is considered factory trailer prep, no aftermarket parts and splicing/converters its, no "homeruns" needed to the battery for aftermarket wiring kits and I now have ALL Lexus components installed that leverage the factory prewiring... So, the $265 seems more in line considering Lexus charged me $180.00 for parts. KUDOS to my local Lexus Dealer that helped me work through the jigsaw puzzle on the parts end of things.
So here are my final thoughts::
For the RX350L with out the towing prep, perhaps Lexus is hoping you don't tow by stating in the manual that it is not recommended and additionaly they do not make it easy for one to install the factory prep trailer wiring as they do not provide the towing wiring harness "inactive" without the towing prep as they often did in previous models.
From a weight perspective, I can understand, the RX350L is 240ish lbs more overall than the standard RX350 and if one gets the bench vs the cabin chairs, there is:
1) An extra body of weight to contend with (take your pick of how large) and
2) The bench HAS to weigh more than the "captain chairs". So, much easier to just state do not tow vs , well if you add Jimmy and Sarah and have the bench vs the captain chairs, PLEASE don't go over X weight without the towing prepped out (oh yes, lets not confuse folks further that may have figured out that the 350L already comes with the mechanical tow prep parts and half the wiring...). In fact I am sure Lexus is pushing the limit of the capacity by allowing towing with the captain chairs alone although I would think Lexus Engineers are conservative when they state "3500 lbs" max towing and ALWAYS over Engineer. That is what we "Engineers" do right?.
It make sense that for the ALL RX350Ls, mechanical (ie. HD radiator, alternator, covers, etc..) tow prep parts ARE all installed as the additional vehicle weight of adding the third seat and 2 additional passengers and possibly the bench vs captain chairs plus cargo weight DOES put additional strain on the engine...
For my 2020 RX350L I am pretty certain that the HD radiator, transmission and engine cooler assembly and now after my install, the factor towing WIRING is in place.
SO, to be conservative, I am thinking that if I stay below #3200 Lbs, that might be a safe #??? The recommended weight is ONLY where I feel personally feel comfortable, I encourage you all to research, share info and come up with your own independent conclusion and decision should you choose to tow with the 350L with no tow prep.
I am happy that only 2 parts where need to replicate the factory trailer wiring!
I feel much better now as I really wanted the towing prep and what I have discovered meets my expectations (way better than 0!!)!! I will share some tech pics soon. Best wishes to RX350L folks looking to tow with the non tow prep and bench seats and others that are curious, I hope my findings help you!
Thanks,
Hi, great post. I need some additional help here and I am not getting it from Lexus. I have a 2018 RX350L with no tow package, however, i did install the Curt hitch over the weekend. Do you know if the same alternator radiator and trans cooler were installed in all 2018 RXLs? I will confirm radiator part number and transmission cooler this evening when my wife gets home but I do have plug 16-82180 in the rear. Myself and Lexus can not find part number 17-82180, do you have another part number? Do you have a pic of the 17-82180 wire harness prior to installing it? Do you have a part number for your alternator? This has been frustrating as hell to say the least and Lexus is of no help! Or and they dont provide part numbers! Thank you!
Hi, great post. I need some additional help here and I am not getting it from Lexus. I have a 2018 RX350L with no tow package, however, i did install the Curt hitch over the weekend. Do you know if the same alternator radiator and trans cooler were installed in all 2018 RXLs? I will confirm radiator part number and transmission cooler this evening when my wife gets home but I do have plug 16-82180 in the rear. Myself and Lexus can not find part number 17-82180, do you have another part number? Do you have a pic of the 17-82180 wire harness prior to installing it? Do you have a part number for your alternator? This has been frustrating as hell to say the least and Lexus is of no help! Or and they dont provide part numbers! Thank you!
Any Lexus dealer's parts dept can input your VIN to their system and printout a copy of your car's window sticker. It will show everything your car came with either as standard or optional.
A few inquired about the location of the converter and pigtail swap, it is the Driver side rear section of the vehicle.
The Converter plug is plug and play, there should not be one there with no towing package, simply remove cap and plug in the new relay. To the farther REAR side of the vehicle in the same area, is the the wire 16-XXXX that need to be swapped with 17-XXXX. You will see the plug when you remove the panel. Please look at pics above for reference to swap out the pigtail and let me know if anyone has a question. Thanks!
Re these pics:
How easy or difficult is it to access the area that the Converter plug goes? I assume it's accessed through the interior?
ViktorG - This is the best "how to" video I've ever seen. Our 2021 RX350 has a factory installed trailer hitch. I did not realize how much work was involved. Ray A.
Been looking for a solution for our 2021 RX350L without tow prep. The dealer says no-go, but if the 2021 is the same as the 2020 we should be good. Does anyone know for sure if the same applies to the 2021?
Been looking for a solution for our 2021 RX350L without tow prep. The dealer says no-go, but if the 2021 is the same as the 2020 we should be good. Does anyone know for sure if the same applies to the 2021?
Another member posted on here that he has a 2020 RX350L w/o the tow package and he said it's all the same except the actual hitch and wiring harness. I just added a tow hitch to my 2020 RX350 w/o the tow package. If you're remotely handy, you can do it yourself.
I ordered a hitch receiver (Draw-Tite, part # 75540, $193.00) from etrailer.com I also added the mounting bracket (C42CR, $3.69), a No-drill mount (18140, $12.22) and because I was on a roll, I threw in an LED 4-way flat connector (vehicle end) tester ($4.04). Now the wiring harness, that's the easy part. I went to U-Haul and bought their wiring harness for the Lexus RX350 (Highlander, part # CMF56217) for $32.95 plus tax. It has everything you need. I'd also go to Harbor Freight and get their Protective Wire Wrap to clean up the wiring harness. That's everything you need to have a working Class III hitch with lighting. You'll have to cut a 3" x 3" section out of your plastic. A hacksaw will work fine (remember, measure twice, cut once). The directions are very easy to follow.
Again, if you're remotely handy, you can do this.
My picture shows it installed. Look closely at the area above the hitch. You can see the area I cut out. Also, if you have to toe kick tailgate opener, you'll have to disable it in your settings. You'll also have to move the sensor before you cut the bumper, then reinstall it (just a few screws) after you make the cut.
If you haven't, lay on the ground and look up under your bumper and you'll see what I'm talking about. It really is pretty easy.
I'll send you a PM with my name and phone number. Call me and I'll explain it more.
Hi, I realize this is an old thread but I am hoping to get information on the pigtail harness part 17-82180 mentioned as being needed for a 2018 RX350L without factory tow package. I've installed a receiver and purchased a Curt Wiring Harnes C56217 from etrailer.com. I found the 10 pin connector in the driver-side rear but cannot locate the 4 pin connector. I believe part 17-82180 is what I need to replace the factory harness, but this part number doesn't come up when searching online. Is anyone able to point me in the direction of finding/ordering this part? Thank you
Hi,
I've got 2018 350L, that I want to mount a bike rack via a tow hitch. My RX didn't come with a tow hitch or tow hitch prep. My question is, lexuxpartsnow indicates that the PT228-48180 (tow hitch) & PT228-48181 (tow hitch bumper cover) will both fit my vehicle. But my local dealer (plano texas) says that it wont fit unless I have the 450L and captains chairs for my middle row. This doesn't make sense, does anyone have any experience with this??
TIA
Steve
04-28-21, 03:53 AM
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