waquidvp

I initially had these same concerns, but I have been running with them for a few weeks now and I haven’t noticed any difference from before.

So the way I ended up solving this is by using a NA (North America) Radar and Driving Support ECU. Depending on which car you have, it might be easier to find EU parts.

Small update on my experience so far: TLDR; If you use JPN spec parts, mainly the DSU, your max speed will be capped at 73 MPH. If this is a problem for you, use NA (North America) or EU spec parts. Most things have worked very well, however I noticed that the max speed you can set is capped at 73 MPH. After doing some research, this seemed to be a limit set on JDM cars due to local rules. This made sense, since the DSU that I had fitted was Japan spec. First I thought that resetting the DSU to it's virgin state would resolve the issue, however that didn't seem to fix it. What I ended up doing was writing the NA (North America) spec data onto the DSU, I got this from the screenshot posted by @SPC. I also had to swap the radar to an NA spec one, but I already had one spare from my previous attempts to get this working. Ideally, I would get EU spec parts, but I haven't found any EU spec radars on the market so I have had to result to either JPN or NA parts. On another note: @ianhu I will get back to you with those part numbers as soon as I get some time on my hand to do the research.

Hey ianhu, Yup, my car is a UK car, it's an IS250. However the DRCC/PCS systems aren't too different between them. You will roughly go through the same steps. It might even be easier to find part since the IS300h is more common in the UK, even when I was looking for parts for mine, I would come across alot of IS300h parts with very similar part numbers. Happy to help with finding you the right part numbers etc. Would need your VIN for that, so feel free to DM that to me. I also have some left over parts which might be usable for you. About Comma 3, I had also explored it for a while. In it's current state, I don't think it would work with our cars. You need to at least have the 2017 facelift version of the IS which has the updated safety system (Lexus Safety System+) that includes steering assist (I think the technical term is Lane Keep Assist - LKA) which Comma 3 relies on. However, if you find something else, feel free to put it on here.

After following the above instructions, big shout out to @SPC, it works! I also found that you don't actually need to do any modifications to the DSU, only the ECM. It just means for who ever tries to attempt this, it's one less step. The setup I have working is with a Radar and DSU that are both Japan spec, even though my car is EU spec. I am also using a newer DSU than the one which is spec'd for the car. I am using Part No. 88150-52053 instead of 88150-52052 (which I never could find anywhere). This confirms that, you can use a Radar and DSU which is a different spec from the rest of your car, the important thing is to keep the DSU and Radar the same region. This should be helpful for anyone who is trying to get parts but can't find them in their same region. I have found some of these parts are much cheaper in the US. I will keep testing it and report back if there are any issues or DTC's that come up, but so far it's been clean. I am also fairly certain that I need to get the radar re-calibrated/re-aimed, even though it seems to be working without it for now. I am also planning to do a full write up for whoever want's to attempt this in the future.

Wow this is very interesting, it was plug and play for me. However mines is a 2015 IS250 Base model. Once I plugged the camera in and put the car into reverse, the screen switched over to the camera. It’s worth mentioning that it doesn’t always work for me, once every 25 or so reverses, the camera won’t show up on the screen. This might be something else but I haven’t investigated much since it only happens so rarely. Turning the car off and on again seems to fix it.

Hope it all goes well with the cutting, I used a Dremel but it was a little difficult cause it was my first time cutting into a body like that. Excited to see the result!

I managed to get in touch with the CT200H owner, looks like that was a successful project. With regards to my status, it seems like the PCS side of things are working. Yesterday I was surprised with the "BRAKE!" warning when I came a little close to someone at the lights. So the issue seems limited to the DRCC part.

Yup, that's the right connector. I have a 2015 IS250 and have successfully fitted the OEM reverse camera. After finding a used camera on eBay, plugged it in and voila, put it in reverse and seems to work. However, the main issue I had was with cutting a hole in the boot, my boot didn't have a hole for the camera to go through. I was able to do this with a Dremel tool. The cuts I made weren't perfect, it was my first time trying to use a Dremel on my car. But once the camera and moulding goes on, those will be covered up. You will also need to change the boot moulding to one that has the camera cutout. I am not sure, but maybe you will be lucky and the cutout in the boot is already there, I am not sure. Here are some pictures I had taken back when I did it. Connector: Cutting: Installing Camera: Final Result:

Another example of a project out in the wild, this time for a CT200H. No confirmation on if it was successful or not: https://www.clublexus.com/forums/ct-200h-model-2011-2017/928713-retrofit-radar-cruise-control-2.html.

While writing up this post, it required me to review all the work I had done so far. I found that I was using the wrong Network Gateway ECU, I thought this could be the root cause, so I got the correct part, which was 89100-30160 instead of 89100-30221 which is from a newer production batch. However after trying it out, the same issue persists.

Just to update this thread, I managed to find another project that seems to be experiencing the same issue. Haven't managed to get a response on if it was resolved. See their post: https://www.clublexus.com/forums/rx-3rd-gen-2010-2015/935954-lexus-rx450h-2009-cruise-radar-retrofit.html.

It would be quite straightforward if Lexus still sold the Driving Support ECU, since this is the only part that is very specific to the vehicle, the other parts are somewhat shared with other models, however after asking multiple suppliers, it’s been discontinued by the manufacturer and no one has any old stock. And unfortunately, from the research I have done so far, I can’t find any cars from this production batch that has the PCS & DRCC option in the UK, so chances of it turning up at the breakers is near to zero.

After seeing a few examples of folks in the community attempting to retrofit PCS (Pre Crash System) + DRCC (Dynamic Radar Cruise Control), some successful and some not, I thought I give it a go on my 2015 IS 250 base model. After figuring out all the parts required, I started on the adventure of trying to get them. Here are all the parts that are required: Cruise Switch (84632-30020) + Wire (84633-76020) for DRCC Steering Controls (84250-53231-C0) Lexus Emblem for Radar (53141-48050) Radar (88210-53140) + Bolts (3x 90119-06782) Buzzer (86652-50010) Network Gateway ECU (89100-30221) + Bolts (2x 90159-50327) Driving Support ECU (88150-53052) + Wire (82143-24020) + Bolts (94151-80600) PCS Cancel Button (84770-50010) Engine Wire Harness with Radar Connector (82112-53340) Most parts were available in the used market, mostly eBay. Some from within the UK and some from the US. The parts that proved to be more difficult to find were the Driving Support ECU and a matching Radar. The Driving Support ECU part number that is required is 88150-53052, however from a quick Google search, the only place this part number appears are in parts catalog websites. Digging a bit deeper I first found it on sale in Vladivostok, on a Russian site called wiweb(blocked word). Here is the full link: https://www.wiweb(blocked word)/goods/elektronnyiy_blok_lexus_is250_8815053052_gse30_4gr_8815053052-198031S2997547103.html. I reached out to the seller however he wasn’t sure about how I would pay him and also how he would ship it to the UK with the current restrictions in place. After looking at the parts catalog, I found two other part numbers, one for an older part (88150-53051) used in a previous production batch (2013/06 - 2014/07), and one for a newer part (88150-53053) used in a later production batch (2015/08 - 2016/10). My vehicle was produced 2014/11 and the part I am looking for is from the 2014/07 - 2015/08 production batch. I thought I start looking for these parts in the hope of widening my chances, keeping in mind that these might not actually work in the end. I ended up finding these in Japan, on Yahoo auctions, and bought them through ZenMarket since Yahoo auctions is not available outside of Japan. At first, I found the newer part (88150-53053), and ordered it. As I waited for the Driving Support ECU, I managed to get the rest of the parts. I fit the Network Gateway ECU, swapped the steering controls, changed the engine wire harness to the one with the radar connector, the radar itself, swapped the emblem in front of the radar, and finally fit both the PCS cancel button and buzzer. The only thing now remaining was the Driving Support ECU. It’s worth mentioning that the new cruise switch, even though it’s the one for using with radar, works with standard cruise control. Once the Driving Support ECU arrived, I plugged it in and hit my first issue. I got the following DTC: C1A0A - Front Radar Sensor Region Code Mismatch. Using Techstream, I found that the Radar had the country code set to NA (for North America) and the Driving Support ECU had the country code set to JPN (for Japan). This made sense since the Radar came from the US and the ECU from Japan, so then I ordered a Radar from Japan, again through ZenMarket. After I got the Radar from Japan and replaced the US one, through Techstream, I used the initialisation utility on the Network Gateway ECU. After clearing all the previous DTC’s, started up everything and no errors. I can now see a cruise control tab in my instrument cluster and when using the cruise switch and the distance switch on the steering, everything seems to react accordingly. When turning on the cruise switch, I can also see “Radar Ready” in the instrument cluster. I went for a test drive, got the car to around 35 MPH and set the speed. For around 1 second, I see the set cruise speed in the cruise control tab but then get an error: “Check Cruise Control System”. Using Techstream, I get the following DTC: C1A52 - Driving Support ECU Communication Abnormal. I will try to record the exact behaviour and post a video soon. My first conclusion was that maybe since it’s a newer ECU, it’s not fully compatible with the rest of the system. After resetting all the ECU (by disconnecting the negative battery terminal for around 5 minutes) and trying again, I get the same DTC. Currently I have few theories, but no way to test them: Even though there is no region mismatch error being shown in Techstream, since all the other ECU’s, mainly the ECM and the multiplex ECU, in my car would be set to EU (Europe) I suspect that might still be problematic. This is hard to correct, since I can probably never get a Driving Support ECU with the correct part number and region. Since the ECU I tried is newer than the one needed and doesn’t match the exact part number, I thought I give the older ECU a try, this was in the market at the time on ZenMarket, so I went ahead and purchased it. Unfortunately that also leads to the same DTC. Other examples from the community: 2011 GX 460 - https://www.clublexus.com/forums/gx-2nd-gen-2010-2023/921818-retrofit-oem-radar-cruise.html 2015 GS 350 https://www.clublexus.com/forums/gs-4th-gen-2013-2020/883922-pre-collision-system-retrofit.html 2008 GS 450h https://www.lexusownersclub.co.uk/forum/topic/131146-lexus-gs-450h-sport-radar-cruise-control-retrofit/ If anyone has any ideas or thoughts about how to go forward, feel free to respond to this thread. DTC C1A52.pdf DTC C1A0A.pdf