I just got a 2025 Prius Plug in XSE Premium (with advanced technology package, and every premium feature) a couple days ago, and am trying to figure things out? So please forgive newbie questions. (I also agreed to the trial of all subscriptions, although I don't know if I will continue them after the trial?) I recall seeing something about "Traffic Jam Assist". As I will drive the car on the freeway (LA) for the first time today, and may well encounter a traffic jam, I am curious about that feature, to perhaps learn about it before that drive today? I looked in the index of the manual, and it is not listed there. Can anyone tell me about that feature? Do you find it useful? How do you use it?
I find it very useful. It moves the car along with traffic, keeping the car in the lane and avoiding other cars. I don't like the way it engages/disengages on its own. I've never found a way to activate it myself. Also, it keeps asking if you want to consent to being recorded. I can't think of any benefit to that, so I always refuse. It stopped happening when I found a way to disable the DMC (driver monitor camera) in the setup.
Thanks. You don't know how to engage it though? It just starts without being turned on? yes, I think it requires the driver monitor camera. They want to make sure you are still alert and paying attention, not dozing while it drives~;-)
It will turn on automatically if the following conditions are met: - You have an active Drive Connect subscription - You are driving less than 25mph(or thereabouts) - You have Adaptive Cruise Control on and set - You have Lane Tracing Assist on - There is a car in front of you - The cameras on the steering column can see your eyes - I think you have to agree to being recorded, but I'm not 100% certain on this(the regular Prius doesn't have TJA, so I haven't used the system myself to test) If all these conditions are met, the system will activate automatically. You can't force it on. Once it's on, it will shut off automatically(after giving you a warning) if any of these conditions are no longer met. I believe the TJA section in your manual starts on pg 348.
It sounds like improved cruise control that doesn't auto turn off at full stop. Does it auto lane-changes? Probably not.
The only differences I can see between Adaptive Cruise Control and Traffic Jam Assist is that the car will accelerate from a dead stop on its own and you don't need your hands on the steering wheel for it to function. ACC doesn't need to be reset after a full stop, but you have to initiate the acceleration with the pedal. You also need to either have your hands on the wheel(PHEV) or give an input to the steering angle sensor(HEV&PHEV) every 15sec for it to continue to function. It can't decide to lane change on its own, but it will perform a lane change(if safe) if the driver commands it by partially pushing the turn signal lever for two or three seconds(Lane Change Assist). Differences between the PHEV and HEV safety systems and what those changes mean: 1. PHEV has the capacitive touch steering wheel 2. PHEV has front side radar(required for Front Cross Traffic Alert, Lane Change Assist, and Traffic Jam Assist) 3. PHEV has driver monitoring system(required for Traffic Jam Assist) Any HEV can add the capacitive touch steering wheel easily. A Limited with the Adv Tech Package can physically add the front side radar easily, but the programming of the new sensors is proving to be a nightmare due to a bug in Global TechStream. All other HEVs would need to add wiring to add the radar plus still have the programming problems. I suspect you could add the driver monitoring system to a HEV, but it probably means pulling the dash, and I don't know how easy any programming would be.
The only other thing I can add, per the Owner’s Manual, is that Traffic Jam Assist (TJA) is only available on "some highways and expressways". That restriction finally made sense as to why TJA requires an active Drive Connect subscription. Since Drive Connect provides Toyota’s cloud-based navigation and real-time traffic data, it also provides Toyota with access to your vehicle’s precise location, which in turn lets Toyota determine whether you're on a TJA-approved roadway.
I don't find myself on highways where the feature works but I did have a chance recently. The biggest difference I noticed between regular ACC with lane centering and ACC with TJA is I don't need to have a hand on the steering wheel while it's active (under 25mph). It still needs baby sitting to keep it active where the speeds are right around that transition between regular ACC and TJA. hands vs hands off. Because if my limited use of roads where I can use the feature I'll most likely cancel it once my free trial is up.
