The Ugly Blue Truck - Now With Feeble Attempts at Remapping Volume/Seek Buttons!

REMAPPING STEERING MEDIA CONTROLS (PART 1)

• PART 1 -- You are here!
• PART 2
• PART 3

Instead of taking "What Have You Done To Your 3rd Gen Today?" further off track with more posts about this, I'm moving anything that isn't the finished result into the build thread where it belongs.

In true "me" style, this project is moving ahead based on the assumption these controls showed up in working order.

Can't wait see how this project turns out...

Parts & tools

Parts

• 75E817 - Steering Wheel Gray Radio Control OEM 2016-2020

Tools

• Phillips head screwdriver

There is a stray blue wire for whatever reason, but it doesn't bother me since this harness isn't the one being installed.

Disassembly

This parts pretty easy. There are three phillips head screws that you need to remove and the back cover pops right off. I also opted to snip the zip tie and fully remove the wiring harness from the back side.



So... what's in there?

The number of wires in the harness it gave me hope there was one wire per button, and this would be as easy flipping a few wires on the harness that plugged into the controls.

But life, much like the internals on this control set, isn't simple like that. Things don't look too bad, though.

Shot of the circuit board with the button leads traced:

• BLUE: volume down
• YELLOW: volume up
• GREEN: seek backward

• MAGENTA: seek forward

Detail shot of the area where the leads punch through:


It looks like the button leads all follow a nice simple path and then punch through to the other side of the board. On the back side of the board where the leads come through they attach to a shared lead, with resistors between them.

Ok, so what's the game plan?

Well, I'm a simple man, so just sloppily running jumpers all over the board sounds like it'd probably work...

We're just looking to map VOLUME+/- to SEEK +/- respectively, and vice versa. With a bonus jumper from the severed end of the chain of resistors back to the lead heading to the harness plug.

Here's a crude diagram of how it might end up looking:

• RED: severed connection
• BLUE: volume down
• YELLOW: volume up
• GREEN: seek backward
• MAGENTA: seek forward

What do now?



The actual placement of jumpers is best left to a professional (or at least someone who claims to be), maybe with micro-solder experience. I've called a couple of phone/computer repair shops around town and found one willing to give er' a go.

Later this week the board'll get dropped off, and (assuming it's something they can do) about a week later it'll be back in hand and ready to fry my truck's electrical system.

 

Ambitious. It's not possible to attempt to rotate the 4 way button using jumpers from there to the board?

 

I think we're talking about the same thing?

The request for the PC shop was going to be whatever the technically competent version of this was:



Edit: or are you referring to the button side? I was worried about anything on that side interfering with the rubber mat the buttons are on.

 

Yeah, I was mostly thinking that extending the button with jumpers to the board and rotating it could be the minimally invasive approach.

What you're going to get is buttons which say one thing but do another, granted it's more in line with what someone might expect from other vehicles but still it'll be non-intuitive.

I believe others have looked into rotation of this guy and it's a no go but a closer breakdown of photos might help me understand why/how that's trouble.

The board itself looks manageable.

 

Curious to see how they do with your button remapping. It's not exactly an easy task for a PC shop. The hardest part will be the white connection because the resistor can't be removed and will have to share a pad with the wire. I'm hoping they actually use the test point near R6 instead of scraping the solder mask off the trace between T5 and T8. Anyway expect something that looks like my hack job from a few years ago.

 

Unfortunately the button face is asymmetrical and can't just be rotated. I haven't been motivated yet to break it down further due to a seemingly hidden clip within the button itself.



If it gets bothersome enough maybe I would strip the button and spray it plain black, then take to a local maker shop to laser etch new icons. But that's a few more steps down the road... first is get the rotation work done without frying anything.

 

REMOVING ACCESS CAB REAR JUMP SEATS

It depends on the owner, but in my case the rear jump seats serve no purpose and take up valuable in-cab storage space I'd rather use to securely stash... stuff.

Thankfully @kevin604 already wrote up an excellent post back in 2016 that covers removing the jump seats and accompanying trim pieces. So I followed those instructions and will now proceed to basically plagiarize that post, while sprinkling in a little more detail for anyone who cares.

This guide only covers removing the jump seats. Installation of an OEM delete will be covered in another post once some pending work is completed in a few weeks.

STEP 0 - Suggested Tools
Tools

• Socket wrench + extension
• 10mm socket
• 12mm socket
• 14mm socket
• Interior trim removal kit
• Supplemental trim removal/pry tool(s)

STEP 1 - Removing trim caps obstructing bolts n' sitch

There are nine trim caps either covering bolts, or preventing removal of trim panels. Every cap has a very tight tolerance and the usual plastic trim removal tools were too blunt to get in there without marring everything. This is where the "supplemental" trim removal tools come in; I used pries and spudgers from a small electronics tool kit.

Start with the "SRS Airbag" cover on the rear pillar trim near the headliner, there is one on each side of the cab. The rear side of this cap is semi-permanently attached to the trim panel it plugs into, you can avoid snapping its clips by prying along the front edge to ease the piece out.



There are three trim caps along the top of the rear seat back panel covering bolts that need removed.



The last four trim caps cover the fold down seat hinges and need removed so the rear panel can be uninstalled. These were a little tricky to get out, but working from the top corner of the cap it wasn't too hard to sneak a pry tool in there for some leverage.




STEP 2 - Removing the fold down seat bottoms

Both seat bottoms are a single assembly containing the handle/hinge mechanism as well as the padded seat bottom. Each seat is held in place using three 12mm bolts, which are covered by a small carpet flap that can be peeled back to expose the bolt heads.



STEP 3 - Removing the seatback trim panel

The rear seatback trim panel has a vertical line running down the middle. "This panel" is actually "these panels"... they split into two half-panels.

There are three 12mm bolts (un-capped in STEP 1) that run across the rear seatback trim panel.



Now it's time to pop out the rear seatback trim panel. I started by hand on the passenger side then used a hooked pry tool along the top edge toward the driver side and just pulled until the panel(s) came loose.

Maybe it's possible to yank the panels off without breaking any clips, but a few weeks ago Robby Layton put out a video and in it he mentioned how "all disposable clips are single use." Since then I've decided he's right and breaking (DISPOSABLE) clips is just the cost of doing business.



The last step here is to remove the insulation/sound dampening pad, which is held in place by five small plastic clips. These all came out without any damage using a two pronged pry tool.



STEP 4 - Removing the rear headrests

Both headrests are identical, and are each secured using four 12mm bolts.



STEP 5 - Removing the rear seatbelts

Remove the 14mm bolt attaching the seatbelt to the lower rear quarter trim panel.



Remove the upper and lower quarter trim panels (outlined in green below.) This is one of the trickiest pieces to remove without fucking up lots of shitty little clips, so take care and don't go all Hulk yanking on it.



There is an upper and lower door trim piece clipped onto the one being removed, so start by prying the upper/lower trim a bit to help finesse the quarter panel clips out.



After the ends of the upper and lower panels are pried up, and the clips are released, un-tuck the edge of the trim from the headliner/carpet.

Once the headliner and carpet are free, pull on the back edge (marked in green) of the rear quarter panels, pulling toward the middle of the cab in order to release the replaceable trim clips.



DO NOT keep pulling if it feels like only the front edge (marked in pink) is still clipped; the panels have a J shaped front clip that wraps around the weather seal and other trim pieces.

Here is some detail on the back side of the panels being removed. The disposable clips (white ones below) need pulled inward before the J shaped clips (marked in orange) can move toward the back.





Once the panels are loose, push them toward the back of the cab and the J shaped clips will free up; feed the un-bolted seatbelt end through the trim pieces in order to fully remove them.

The seatbelts are almost out. There is one more 14mm bolt securing the seatbelt near the headliner, and a final 10mm bolt holding the belt assembly in place near the floor. Once the 10mm bolt is removed the whole belt assembly slides out.



The seatbelt buckles are directly behind the rear center console and are each held in place with a 14mm bolt.



Repeat STEP 5 on the other side of the cab.

STEP 6 - Remove the rear center console

The rear center console is held in place by six bolts; four 10mm bolts on the top covered by rubber inserts, and two 12mm bolts holding a small metal bracket in place.

Remove the rubber inserts from the top of the console to expose the bolts.



Once the bolts are out the center console should lift up easy, and reveal a small metal bracket. The bracket is held in place with two 12mm bolts.



STEP 7 - Remove the cargo box lids

With the center console removed the original lids don't fit; there is a ~10" gap in the middle where the console used to be, so they're getting replaced.

Removing the lids is easier than typing this sentence. Open it to about 90deg and push the bottom edge of the lid toward the back of the cab.



STEP 8 - Admire your handiwork



STEP 9 - Take inventory

A lot of stuff was removed here:

• 64271-04120 - Back Panel Trim (Passenger)
• 64270-04160 - Back Panel Trim (Driver)
• 64141-04030 - Sound Absorber
• 71940-04130 - Headrest, Rear (2x)
• Part # unknown - Rear Seat Assembly (Passenger)
• Part # unknown - Rear Seat Assembly (Driver)
• 73705-04020 - Child Restraint Anchor Plate (2x)
• 2488650 - Rear Seatbelt Retractor Assembly (Passenger)
• 2488651 - Rear Seatbelt Retractor Assembly (Driver)
• 64287-04020 - Cover, Room Partition (2x)
• 64287-04030 - Cover, Room Partition
• 64425-04020 - Back Panel Trim Plug (4x)
• 64716-04020 - Cargo Cover (Passenger)
• 64716-04010 - Cargo Cover (Driver)
• 58912-04030 - Rear Console Assembly, Lower
• Part # unknown - Rear Console Bracket

Last but not least

Even with all the right parts a non-factory jump seat install can be dangerous if bolts aren't fastened to spec. Even more so when it comes to safety equipment like seats and seatbelts.

 

Well dang my dingies...Toyota sure doesn't make it easy to switch it out. I'll be looking intently for your guide to installing all the replacements.

 

Were you by chance ever an aircraft mechanic? Do you pass those "Are you a robot" captcha tests? The attention to detail here is amazing, as well as your willingness to take the time and explain everything in simple format. I like crayons and pop-ups, so thank you for keeping me on track with the blues clues reference. I'll keep checking back and admiring your work periodically. As usual, well done.

 

I'm a software developer, and simple minded. So extensive documentation is my friend.

 

REMAPPING STEERING MEDIA CONTROLS (PART 2)

• PART 1
• PART 2 -- You are here!
• PART 3

When I wrote PART 1 it seemed this project had a chance to go relatively smoothly, save for the whole micro soldering thing. But hey, that's why some other schmuck was getting paid to actually pull it off.

Turns out those schmucks aren't quite so schmucky, and nobody wanted to take on the project, even if I'd agreed to their exorbitant rates.

So here I am, left holding my... steering controls.

There goes my hero

Big ups to whoever runs TTGuide.net, that site has some excellent information with regard to diagrams and technical specifications that I figured were only available to service techs. This site came in real handy when documenting the various part numbers that make up the rear seat of the access cab, and now once again researching the steering wheel media controls.

The game plan

Since micro soldering work is well outside my area of expertise the previous plan to break connections and re-route them with jumpers is a non-starter.

Time for a new plan... How about something that involves technologies and concepts I've never in my life used? Yeah that sounds like a good idea. Arduino electrical engineering it is!

Simple enough, just:

• Pop an Arduino controller in between the steering wheel media control board and whatever the heck it plugs into
• Figure out what is output each time a respective media control is triggered
• Use the Arduino to remap various outputs received to different outputs which are desired
• Bob's your uncle

Yeah that seems like just about everything, not a single detail glossed over. This'll be finished before lunch.

So what're the outputs?



Fuckifiknow, dude. Thankfully TTGuide has my back and has provided some good info that seems like it'll come in real handy. The diagram below provides the pinout, as well as expected resistance when each of the media controls are triggered.





So the above covers the actual steering controls. But there may also be the option to handle this inside the dashboard instead, where there is more room and no moving parts to contend with -- which seems preferable.





Opting to alter the outputs at this point would mean no longer having the option to remap the right side controls to arbitrary actions, but honestly, I have no desire for that. So the in-dash solution is looking preferable.

That's all good and well, but by default an Arduino can only read voltages. Electrical engineering is beyond me, but Google isn't. Time to check if resistance affects voltage...

Does resistance affect voltage?

Yes.

How does resistance affect voltage?

To expand on the previous section... "something, something, Ohm's Law." Smarter people know the actual answer, so let's see what they've got to say.

Alright, sick. So Arduino can only read voltages by default and measuring resistance is a pretty big pain in the ass. But it seems that changing resistance also changes voltage, so we're in business.

The Toyota guide only provides resistances and no initial voltage, and even if it did, I've got no idea how to calculate that nonsense.

Next step(s)

With limited information available, it seems that probing outputs using a multimeter is the next logical move. Kind of sucks... that renders most of the resistance info from TTGuide moot, since we're onto voltages now. The pinout provided can still be used, since it does shed some light on which pins carry which control values.

Once the voltages are known, work can begin on whatever development is necessary for the Arduino device itself. But that's a whole other mess best left to PART 3.

 

DYNOMOMETER?... I BARELY KNOW 'ER!

All dyno results were run on the "same" truck, by the same shop, on the same dyno, using the same driver.

All dyno results (besides the baseline) are absolute bizzarro world levels of mind boggling "that's not how this is supposed to work."

This truck is an asshole.


Onto the Numbers...

GREEN is a stock TRD Sport, running:

• Firestone Destination LE2 265/65R17, which weigh 37# according to TireRack.com and 34# according to TireSize.com
• OEM TRD Sport wheels, which weigh 26# according to offcamber
• Total wheel + tire weight (worst case) is ~63#

Test day conditions for GREEN: 41deg F and no precipitation



RED is the same TRD Sport as GREEN, running:

• Kenda Klever RT 35x10.5 R17, which weigh between 69-73# according to The Google(TM)
• OEM 4Runner TRD Pro SEMA wheels, which weigh 25#
• Total wheel + tire weight (best case) is ~94#

Test day conditions for RED: 40deg F and raining



BLUE is the same TRD Sport as RED, running:

• Overland Tailor MT 7.0

Test day conditions for BLUE: 36deg F and no precipitation







Boom, quick mafs:

• GREEN pulled
  • 228.59 HP @ 6.08 RPM (baseline)
  • 221.76 TQ @ 4.85RPM (baseline)

• RED pulled
  • 229.23 HP @ 6.11 RPM
    • +0.279% from GREEN
  • 225.27 TQ @ 4.82 RPM
    • +1.558% from GREEN

• BLUE pulled
  • 220.68 HP @ 6.45 RPM
    • -3.729% from RED
    • -3.460% from GREEN
  • 224.38 TQ @ 4.84 RPM
    • -0.395% from RED
    • +1.181% from GREEN

 

Added some gas today. One of the more expensive mods done to date.

 

I'd previously read accounts of some of your mods but had somehow missed this phenomenal compendium of knowledge & humor. This thread kicks ass!

 

Adding to my watch list, nice detailed mods!

 

REMAPPING STEERING MEDIA CONTROLS (PART 3)

• PART 1
• PART 2
• PART 3 -- You are here!

This'll be a quick update. After a couple months of on-and-off searching, I actually found a supplier who produces the connectors necessary to fabricate a harness that could be used to hijack steering control outputs and pass them to an Arduino, which would in turn emit re-mapped outputs to the head unit.

The man without a plan

The harness shown below connects to the steering wheel behind the airbag assembly. Behind the airbag there is plenty of space to cram an Arduino Uno or similar device and hijack the outputs to meddle with them.

But that's easier said than done. How exactly do you "hijack the media controls"??



Sourcing parts

The only problem is the female end of the harness clip above is meant to be soldered to a PCB and no manufacturers seemed to produce a female end intended for wires.

KinKong Co. LTD to the rescue! After finding the male end on their website, I emailed their customer service who informed me there was no female end in their catalog besides the PCB-mounted variety... But a few days later they reached back out to inform me they did indeed have such a piece that was custom manufactured for another client, and it fit my needs exactly.



Alright so it looks like after a couple hundred more dollars invested in a "maybe it'll work?" this project can move forward.

The man with half a plan

Assuming proper clips could be sourced, here's a rough estimation of how the Arduino would be wired up:



With that harness produced, it's as "simple" as finding a power source for the Arduino Uno (5V if memory serves), and writing some custom logic to monitor for specific voltages related to the media controls in order to remap them to whatever voltage applies to the desired re-mapped control.

Sounds easy... right?


Next step(s)

First, produce a harness that can be used to monitor the output voltages when specific controls are pressed and log them.

Second, produce a harness that can connect to an Arduino and then connect the Arduino outputs back to the vehicle.

Third, write some half-assed C code to monitor input voltages for those we logged, and output different voltages in order to re-map the controls. (This ALL assumes the truck cares about what voltage it receives, and does not monitor the actual resistance on the circuit...)

Fourth, hook it up to the truck and fry the on-board computer.


Questions remain!

First and foremost, I would like to bench test this whole mess before ever connecting it to the truck. To do that, I'd need someone to help me identify which wire/pin on the PCBs are used for power, and how much power it requires. Once that's known, I can get these controls running in isolation on a workbench and do all the testing and coding without ever involving the truck until it's time to install and test things.

 

Cool project. What do you want to remap the buttons to?

 

For me, it's simply swapping volume up/down with prev/next track. Presumably if this works though, you could remap any of the media controls to any of the others -- like a Maestro allows with aftermarket units.

• PART 1
• PART 2
• PART 3

 

yeah weird they mapped them the way they did from the factory. Hope you figure it out

 

Zak, question for you since you bring it up here again, what exactly is the reason why you are using the stock head unit vs aftermarket?