RainMan's 2021 Lunar Rock TRD Pro Build

e30cabrio · Jul 18, 2025

nasher75 said: ↑

Have you pulled it out and inspected components, traces and solder points on the PCB for anything that has obviously failed on the unit?
Click to expand...

Yup, looks fine. They said outside physical damage (which would cause cel,) it can't fail.

I'm thinking everything man made can fail.

e30cabrio · Jul 18, 2025

I told him his booster does nothing, the diode increases voltage but I prefer not to go fuseless.

His response :

Ok, thanks for the info. Based on what you are describing, I suspect there is nothing wrong with the booster and there is another variable. But please send it in so I can take a look at it and i'll swap it anyways.

How is there nothing wrong with his product?

TRDFerguson · Jul 18, 2025

e30cabrio said: ↑

but I prefer not to go fuseless.
Click to expand...

I present… a diode with fuse!

e30cabrio · Jul 18, 2025

TRDFerguson said: ↑

I present… a diode with fuse!

Click to expand...

That's the diode I put back to test. I had that contraption when it was installed, can't find the fuse holders (to be honest didn't look too hard) lol it's just a fuse right now, I'm trickling the battery to hopefully keep it from failing after sitting for a month.

RainMan_PNW · Jul 19, 2025

e30cabrio said: ↑

Have you had any issues with the booster? Mine stopped working with it in or out at both settings I'm between 13.2-13.6 on a new OEM 180 amp alternator. I emailed them asking for a replacement
Click to expand...

No problems here. I have it in the low setting, and consistently run ~14.2v according to the Alpine radio readout

e30cabrio · Jul 19, 2025

That's where mine ran before 14.6 in high.

Now there is no change, 13.2-8 without it, 13.8-14 with the GM diode now.

AKYeti · Aug 11, 2025

RainMan_PNW[OP] said: ↑

This weekend I finally got the BSM/RCTA fully installed.

Update 12/13/22 - I've added factory parking sonar as well, and that has revised some of the pin-out and wiring harness information I currently have in the truck. See this post for those details. The wiring information below is still pertinent if you are ONLY adding BSM and want to go the easiest route.

This will be a long post, and I’m going to probably edit it a few times to get everything captured, but here goes:

First off, the TRD Pro I bought is based off of the Limited trim - which is one of the reasons I waited until 2020/2021 to buy a Pro. It has the Auto AC controls, heated seats, moonroof, leather power seats, “premium audio” (for what that’s worth ). But, for some reason, even though they based it off the Limited trim, they still cut out some of the things that I guess are “optional” on a Limited but really shouldn’t be. And one of those is the BSM setup. And when I saw that the Canadian TRD Pro did have it, that got me thinking...and as I was working on some other mods I saw signs that it might not be too complicated to add them.

Of course, I didn’t have mirrors with the BSM lights, so I didn’t think too seriously about it until I started shopping for tow mirrors. Ultimately, I bought the Boost Auto tow mirrors and ordered them with the BSM lights in them, so now I HAD to actually add the BSM sensors and wiring...

So it was time to really start digging into the wiring diagrams first. It just so happens, I know of a post on here that has them. From the wiring diagrams, I had to start chasing down what WAS and what WAS NOT already in place in the truck. As it turns out, there are only a few interior wiring harnesses made, and in the TRD Pro, I was able to determine that all of the wiring in the cab was present for the BSM system. Another bonus was that the BSM system runs through the main ECU (where the sonar parking sensors have a separate ECU - which is part of the reason I did not bother with attempting to add those).

When I had the door panels off to install my tow mirrors, I was also able to confirm that I had the wiring in the door panels all the way to the connector for the mirror that would power the BSM, so that was all good as well. So then I had to start looking at the body wiring...and that’s where the work came in. There are a couple of different main body wiring harnesses, and the one in the TRD Pro does NOT have any wiring for the BSM or parking sensors. Additionally, there are a couple of “Body 2” wiring harnesses (the one in the rear bumper), and again the TRD Pro has the one that does not have any wiring for the BSM or sensors. The main harness would be a couple thousand $ and require a full removal/reinstall of the body harness (no small feat without pulling the truck apart), so I needed to go to Plan B there. And the bumper harness, while about $170, would include wiring and connectors for the parking sensors that I didn’t care about.

Ultimately, I decided I would make up my own second wiring harness for inside the bumper, and then connect it to another new wiring harness running down the body to connect into the connector in the engine bay that then runs into the cab and hooks up to everything that was already wired. That decision was followed by MANY nights of checking/confirming connectors, pinnings, and planning out what connectors and terminals and other parts to buy to put it all together. I also made up a custom EWD for the actual routing I was going to do (it differs from the factory slightly only in the fact that I ran all of the body harness wiring to a single connector for the BSM, instead of splitting it across two connectors the way the original harness does.

I’ll attach the custom EWD to this thread when I’m all done, as well as the custom details for all of the connectors that were involved and what the final wiring was at each of those connectors.

Parts needed:

QTY 2 - 88162-0C051 BSM Radar/sensor (I sourced mine off ebay)

QTY 1 - 88171-0C010 BSM mount bracket left

QTY 1 - 88161-0C010 BSM mount bracket right

QTY 1 - 89747-02010 RCTA buzzer

QTY 12 - 90182-A0022 flange nut (go to the hardware store and buy M6x1.0 flange nuts for these)

Mirrors of your choice with BSM lights in them

QTY 2 - 90980-12380 female 10-way sealed connectors w/ terminals (buy them direct from Corsa Technic here) - use the terminal size for 20AWG wire

QTY 1 90980-10891 female 8-way sealed connector w/ terminals (buy from Corsa Technic) - use terminal size for whatever wire you choose to run the length of the truck (I did 18AWG).

QTY 1 90980-10890 male 8-way sealed connector w/ terminals (buy from Corsa Technic) - I used 20AWG wire to match what I used in the bumper wire harness

20AWG 2-conductor twisted/shielded wire for the CANBUS wiring - I ordered this stuff (overkill) from Corsa Technic. I bought 20 feet, but used maybe 6 feet of it.

Extra seal plugs for the above 10-way terminals to fill in the unused ports

82998-24290 female unsealed 0.64 II terminals for inside the engine bay

82998-12590 female sealed 2.3 II terminals for the CANBUS junction connector at the rear wiring harness

Tons of zip ties

~20 ft of 3/8" wire loom tube

plenty of 20AWG and 18AWG stranded wire in various colors

The first step was getting the actual sensors installed. You have to have resin bumper covers for this (which the Pros have)...the chrome end caps would interfere with the radar.

Drop the spare tire to give yourself room to work. Pull off the top cap on the bumper corners. Start at the leading edge and most of the clips will pop except the two that are next to the main bumper cap. Those you’ll need to carefully work with a screwdriver from underneath while also lifting from above (a helper makes this easier).

Next, off comes the main bumper cap. Pull your license plate and there is a plastic clip behind that to remove. Then get up under the truck and push in the clips on the trailer plug to push it through to the outside of the bumper, followed by removing the plug from it. Remove the license plate bulbs from their sockets.

Then there are two more plastic clips at the bottom to remove, and then a bunch of tabs that require some prying from underneath and lifting from above to get it free.

Next is getting the end caps off...or mostly off. You’ll find that the leading edge uses some one-way serrated clips along the front edge that are impossible to actually reach to release without fully removing the bumper, so I left them in place and just “flexed” things carefully out of my way.

Remove all of the other clips on the bumper caps and they will mostly be out of your way (though it’s still a tight fit) to get your hands in there.

I assembled the BSM sensors onto the mounting brackets first, using three of the flange nuts on each bracket.

Then, working from underneath, get the bracket onto the threaded studs that are on the bumper frame and get the other three nuts in place and tighted up.

Next we turn our attention to the wiring harness in the rear bumper. The two BSM sensors are connected to each other via a set of twisted CANBUS wires, and then have individual wires that feed back to the engine bay.

I built the LH (driver's side) connector first, which is S5 on the EWD. The twisted pair wires need to be long enough to reach the other end of the bumper to catch the RH monitor, while the other wires need to reach the right-side frame rail where all the other connectors are clustered already.

I loomed up the wires and started routing it through the bumper just to get a more accurate final length. Zip-tie the loom to the hole on the bracket as you turn up and then into the frame of the bumper.

I also prepped the RH connector (S6) except for the two CANBUS wires from the LH connector (to start), and then rough-routed those twisted wires over to get a length on them before terminating them in the S6 connector.

I then figured out the final loom length, trimmed it, and tucked the wires into it and wrapped it back towards the point that the harness would turn toward the connector to go up in the truck frame.

Once the routing through the bumper was all finalized, I was able to then terminate the male side of the SR2 connector that I used for the junction at the rear of the frame (the right side half of the connector image).

Follow this up by final wrapping the wire loom, getting it all zip-tied into place (to the existing wire harness where possible), and then proceed to put the bumper back together.

(Picture is from starting to install the body harness wiring, but shows where the rest of the bumper harness ended up).

With the sensors installed and the bumper harness done and all that buttoned back up, the next step is getting that all routed through the frame up to the engine bay.
I started out by making up the other side of the SR2 junction with full spools of wire so I could run them out to the actual length needed once up in position. Yes, my workbench is a hot mess...

When routing from the male side of SR2 (body/frame side of the junction), there are a couple of wires that don’t go all the way to the engine bay. One of them is the common ground for the BSM sensors (white for me), which routes to a local ground point on the frame above the spare tire (the main harness grounds here as well).

The other are the two CANBUS wires (green and gray, twisted for me), which terminate at a junction connector called R17. This is a regular looking connector, but the “male” side is actually a jumper/junction terminal block where the four left pins are all one common jumper, and the four right pins are all a separate common jumper. In this case, the various CANBUS functions from the rear of the truck jumper here to send signals back to the ECU.

Next, I plugged in the connector and strung out wire to make sure I had enough to get to the junction box inside the engine compartment (passenger side near the firewall).

Then start looming up the wires, making sure to split off the two CANBUS wires and terminate them in R17.

Terminate the ground on R1 and then tuck everything up nice and tidy above the spare tire mount before continuing to run the new harness along the existing harness to the front of the truck.

For routing the loom, I followed the existing main harness and the two harnesses I had previously added for the tailgate lock and bed lights. Zip tie things together every 8” or so along the entire route. Jack Jack Badoo was “helping” the best he knew how...

When you get up to the front cab mount, you want to fish the harness up along the high side of the existing harness where it passes through the passenger fender well. I added extra zip ties here to keep it secure.

Then follow the harness up into the engine bay and get ready for part three... You can also put the spare tire back now if you are confident in your connector and terminal crimping skills...you’re done under the truck at this point.

Part three is actually terminating into the RA6 connector in the passenger engine bay junction box. This isn't the easiest place to work...and I realized once I got in there that the terminals I needed to hit were all the smaller size ones that are made for 20-24AWG wire and I had run 18AWG in the new harness.

So, I grabbed my 20AWG wire and made up some same-colored pigtails about 6" long with the right terminals in them and got those all plugged into the female connector. Then I needed to strip, solder, and heat shrink those pigtails to the main wires I had routed from the rear of the truck.

I had bought a "fourth hand" setup off Amazon that consists of a metal plate and some aligator clips on long arms that are magnetic, along with an add-on magnifying glass with a light (face it - at 44 I'm starting to realize I need glasses). These conveniently mounted to the truck body inside the engine bay so I could steady the wiring for soldering.

Once everything was soldered and heat shrinked, I tucked it up neat, plugged in all the connectors, and covered up the junction box again.

On to the very last step - the RCTA buzzer. This is located in the "C pillar" on the driver side. And at this point, it was also getting dark on me.

First pull the weather stripping along the rear side of the drivers rear door. Then, you can pop the plastic lower trim toward you to dis-engage it from the two white clips that hold it in place (it will remain locked in place at the bottom by the seatbelt). Peaking inside, you'll see a black connector with a green and blue wire - that is for the buzzer.

Working like a contortionist, get the buzzer mounted in the small oval hole you'll see near that connector, and then plug the connector into the buzzer.

Then re-connect the trim to the clips and reinstall the weather seal.

Next, jump in the driver's seat and fire up the truck. Right away, the BSM and RCTA lights showed up on my instrument cluster.

I then went into the instrument cluster menu to the setup and checked that BSM and RCTA were turned on. I turned them off, then back on (one at a time). When BSM turned on, both mirror lights lit up for a couple seconds. When I turned on RCTA, the buzzer went off and both mirror lights flashed.

Mission accomplished!

Check the attachments for the full customized EWD and the excel files of the above connector mappings.
Click to expand...

I’m blown away by how talented some of this forum’s members are. You sir are a notch above most and I applaud your due diligence and patience bringing this to fruition- excellent work! Once everything went electronic, I slowly backed away as intimidation overcame confidence to do it myself. When all was said and done, in terms of cost of materials I’m curious of what this mod ran you? Also, as far as time, how many hours vested on the install? I’d gladly pay you to make up some harnesses for my 25 SR5 TRD. I might be in your neck of the woods next spring to pick up a camper (either Super Pacific or Lone Peak Overland). I wish I were as talented as you…

martiartisan · Aug 14, 2025

RainMan_PNW[OP] said: ↑

Got the C4 Hybrid installed today.

Jack Jack helped me with the tear down of the old bumper. Getting the SSO bumper off was an ordeal… the 12mm bolt for the driver side lower fender liner was seized up, and getting on it hard just snapped the spot welds holding the square nut to the factory stamped steel piece. So I had to remove a bit more stuff from the front on that side so I could get down inside behind the fog lights to unplug things and reach the nuts. Plus I needed to fully determinate my winch power leads and fish those and the S8 light power cable out through the opening behind the radiator side shroud, so a bunch of stuff came out. I also had a small issue with the Agency6 shackle block - the two screws that secure the pin plate where seized up and the allen heads rounded out. So I had to dremel a slot in them to use a standard flathead screw driver… I’ll be ordering new ones and using a little anti-seize on them when I put them back in.

Then came transferring the light and switch to the new bumper, which was mostly uneventful. Luckily I had saved the original hardware for the S8, because with the SSO I only needed the two side screws - their tabs are on the side of the light and match up with the factory holes perfectly, while the C4 has a tab under the light that uses the BD factory mounting bracket hardware.
I did find that the clutch lever on my X20 Gen3 wouldn’t work in the same position (rotated forward) that I had it in the SSO, so I had to pull that apart and rotate the clutch back to the top position (that will require reaching in a little farther to get to, but not a big deal…there’s a lot more room inside the C4 bumper). I may order a replacement clutch lever that isn’t trimmed now that there’s enough room for it.

With the bumper hanging on two nuts, that was when I realized the hardware kit for it was sitting at my MIL’s in her shop because it’s been too damn wet and cold the past several months to dream of doing stuff at the house. So I had to jump in the wife’s car and run over there to get that small bag of washers and bolts before aligning the gaps and tightening down all the hardware.

Then came carefully feeding all the winch cables and light bar cable back up into position and putting together all the parts that were removed. There’s plenty of room to reach all of the bolts and nuts with this thing, so that was really nice compared to how cramped it is reaching everything on the SSO (because it is made to be compact and look more OEM).

After getting the bumper all buttoned up and the grill back in place, I got the fog lights installed by borrowing some brackets from another set of S2’s that I plan on putting in the outer corners (my fogs were originally ordered with Tundra fog brackets, so I need to source some new brackets for the S2’s). Then reconnected the parking sonar and tucked all the wires up and zip tied out of the way.

Click to expand...

How are the Bilstein holding up with all the added weight up front? I have kings but they are in need of a rebuild so debating on doing that or just switching up suspension

RainMan_PNW · Aug 15, 2025

AKYeti said: ↑

I’m blown away by how talented some of this forum’s members are. You sir are a notch above most and I applaud your due diligence and patience bringing this to fruition- excellent work! Once everything went electronic, I slowly backed away as intimidation overcame confidence to do it myself. When all was said and done, in terms of cost of materials I’m curious of what this mod ran you? Also, as far as time, how many hours vested on the install? I’d gladly pay you to make up some harnesses for my 25 SR5 TRD. I might be in your neck of the woods next spring to pick up a camper (either Super Pacific or Lone Peak Overland). I wish I were as talented as you…
Click to expand...

I don't have the full cost info on hand anymore, but back when I did this (pre-price increases) I want to say it was ~$2000 for all the BSM parts using factory new parts. And another ~$1500 for the parking assist. That's just going off of memory. Total actual install time was around 8 hours for each system. That's not including all of the time spent researching, testing, tinkering, troubleshooting, etc.

NOW, that's for a 2021 Gen 2.5 truck, that's 2021/2022 prices, and that's based on doing my own truck - where I could pop open a panel and check to see if something was there, then go about planning the next step, and working through the process systematically.

For your 2025 - that's an entirely different animal. The wiring changed dramatically with the Gen 3 in 2022. I have no idea if the same options even exist in the new trucks. I have no access to a Gen 3 to experiment on, and really no time to do that anyway. I had two people pay me to do the BSM install in their Gen 2.5 trucks, and after the second one I decided I'm not interested in doing that work for someone else - it's too difficult to support and troubleshoot if they have issues after initial install (especially when I'm 2000 miles away), so if someone wants to use the information I've provided or dig through the EWDs and see what then can do on a Gen 3, then that is entirely up to them.

Good luck!

RainMan_PNW · Aug 15, 2025

martiartisan said: ↑

How are the Bilstein holding up with all the added weight up front? I have kings but they are in need of a rebuild so debating on doing that or just switching up suspension
Click to expand...

I'm super happy with them. I' don't see any issues from the added weight and the truck drives and handles awesome.
I will admit I still haven't found the time to go and really experiment with "dialing them in" - but I've been perfectly happy with them how they are set right now and am glad I went this route.

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