Added FCTA and Lane Change Assist to HEV Prius Limited

After almost a year, I finally got it all to work. Had to go to plan B, but it now works flawlessly.

tldr: I got a pair of used sensors from a wrecked Prius Prime

Full story:
To recap from my old thread, I found out that Limited trim Priuses with the Advanced Tech option package have the wiring for the front side radar sensors that all PHEV Prius Primes/Plug-Ins have. These sensors are required for Front Cross Traffic Alert(FCTA), Lane Change Assist(LCA), and Traffic Jam Assist(TJA). (TJA also needs the IR cameras on the steering column as well as a Driver Monitor Computer, and I'm not interested in installing all of that.)

I was very confident that the Main Body ECU in the HEV Prius was already programmed to be able to handle the sensors. The confidence came from already installing a Prius Prime steering wheel with its capacitive touch sensors into my car with no problems. Totally plug and play.

I ordered a pair of new sensors from Japan(exact same part number but much cheaper than buying from a US dealer) plus all the mounting hardware. I installed them in a couple hours. Just needed to pull the front wheels, black wheel trim, and front bumper cover. I'd rate the difficulty as medium or medium-easy.


But I got an error once I was all done. It turns out the sensors have ECUs on board that need to be programmed by a dealer. But my car didn't have these sensors originally, so the Techstream software couldn't find the correct configuration file. All I needed was the config file for a Prius Prime, but Toyota USA wasn't willing to help, so the dealership's hands were tied. I was sure the project was still possible because FCTA and LCA were now appearing in the car's option menu, but they wouldn't work properly until the sensors were programmed to know they were in a Prius. That's where I've been stuck since early last fall.

As a last resort, I thought maybe I could get a pair of sensors from a wrecked Prius Prime that were already programmed. I was a little worried the sensors might be VIN coded to a particular car, but I figured I'd give it a shot. Turns out they're not, so they'll work just fine in any Prius HEV or PHEV(though only Limiteds with the Adv Tech package have the wiring preinstalled).



If anyone wants to follow suit, I think the best source is Car-Part. They only recently added the correct drop down menu option for these sensors, so pickings are a bit slim. But more sensors should be added by different salvage yards over time. I was able to get both sensors from the same car and they were labeled which side they came from. I don't know for certain if they're programmed for a particular side, but I'd play it safe if you actually try this. Look for a car that was rear-ended if possible.

To find the sensors on Car-Part,
1. Select your year. (anything from 2023-2026 should work)
2. Select "Toyota Prius"
3. Select "Camera Projector"
4. Enter your zip code and search
5. On the next screen, select "radar unit, front, bumper mounted(lane keep assist, bumper sides)"

I was able to get a pair for a total of $300. Mine also came with the mounting brackets, but that's dependent on the salvage yard that picked them.

If they come with brackets, you will also need:
90467-09232 (2) Clip
90189-06238 (4) Grommet
90159-60621 (4) Screw

If they don't come with brackets, you will need:
88215-47050 (1) Bracket, RH (includes one clip)
88215-47060 (1) Bracket, LH (includes one clip)
90189-06238 (4) Grommet
90159-60621 (4) Screw

 

Parts in Japan are just much cheaper overall, but the shipping often makes it not worth it. Small, high-value components like these sensors are perfect for importing. (The comparison is parts from Toyota Japan vs. identical parts through a US dealership.)

I believe I ordered mine just before the tariffs kicked in last year. And the total value was below duty thresholds at the time.

In this case:
882B1-48032 - Sensor, Front Side Radar
$624.74 - US MSRP
$323.95 - best price I could find from a US dealer(includes 25%-off sale)
$172.83 - price from Impex Japan before shipping/tariffs/duties/etc.

Since I needed two, it was a no-brainer.

 

Even today, it would still be noticeably cheaper to order these types of parts from Japan. Here's the current complete prices for two of those sensors through the different methods:

$462 - Impex Japan ($345 sensors + $40 shipping + $43 duties* + $34 merchandise processing fee**)
$648 - Lewis Toyota (25% Black Friday sale)
$864 - Lewis Toyota (regular price)
$1,343 - Generic local dealership (includes an average 7.5% sales tax)

Even if the 15% tariffs are eventually reinstated somehow, ordering from Japan will still be cheaper in cases like this(low size/weight, high value).


Of course used parts are probably the best deal in this particular case(especially since they're pre-programmed). Should be able to find them for $300-$450 depending on salvage yard, shipping, and tax. Mine were $325($300 sensors + $25 tax + free shipping). YMMV


*Duty code: 8543.70.4500
**MPF is a US Customs fee; $34 minimum or 0.3464% of the cargo value.

 

Adding FCTA/LCA to your car would be pretty tough. Physically adding the sensors would be easy, but the problem is that your car doesn't have the wiring for them. You'd have to dive into the wiring diagrams and run a bunch of new wires from each of the front corners, through the engine compartment, through the firewall, then add those wires to the big connectors going into the Main Body ECU under the dash. Possibly even more wiring than that. I never looked into the wiring deeply because I only seriously considered the project after I learned my particular car already had the wiring.

(Toyota originally planned on including FCTA as part of the Advanced Tech option package, but changed their mind late in the process. Late enough that the engine room wiring harness for that option package was already designed and produced. We know this because someone posted the very first brochure sent to dealerships introducing the gen5 and FCTA was listed in the fine print.)




Correct about the steering wheel. The wheel from the PHEV Priuses has touch sensors around about 80% of the wheel. None at the 12 o'clock position, but pretty much everywhere else. Like most sensors of the type, it detects the water in your hand, which means a body part just needs to be very close to the wheel. A thigh can also do the job if your seat and legs are very close to the wheel.

Installation is super easy if you're even the remotest bit used to working on stuff. I can't remember if you have to remove the steering column trim. I remember removing it during the process, but that might have been for something else. I do remember that was a pain because you have to hold the steering wheel in a particular position to access a bolt, then use an allen wrench or hex bit to remove it 1/6 of a turn at a time. And then do it all over again on the other side of the steering column. Not hard, just time consuming and frustrating because you have to do it by feel.

Other than that, you need a long thin screwdriver to pop the airbag retaining clips and then disconnect the airbag(disconnect the battery first). Then a socket on a breaker bar to loosen the nut holding the steering wheel on. If the steering wheel is stuck on, just alternate hits at the 9 and 3 positions a few times and it should come free. Swap steering wheels and (preferably) use a torque wrench to tighten the nut back to spec(I don't remember the spec offhand). Then reconnect and pop on the old airbag.

The biggest problem is cost. A brand new steering wheel runs something like $1200 or more. I highly suggest doing what I did and find a salvage yard with a wrecked Prime/PHV. You should be able to find a wheel for maybe $150. Also note that the PHEV steering wheel has red stitching. I did a complete conversion of my interior to that of a PHEV, so swapping the wheel was actually part of the process. But just letting you know that if you only do the wheel, you'll have one red stitched part.

If you want to do the swap but don't want the red stitching, there's an offhand chance a steering wheel from a bZ4X/bZ/bZ Woodland, new CH-R or Subaru Soltara, Trailseeker, or Uncharted MIGHT work. I don't know if any of those also have the touch sensors, but you could look into it if you really wanted black stitching to match the rest of your car.