Road Sign Assist software updates

[AJones]

Wondered if anyone knew whether the road sign assist (RSA) feature was something which Toyota had released software or firmware updates for, to improve the accuracy? And if so, how you go about getting it updated and typical cost?

My early 2018 Prius Plug-in has RSA and while it is a nice idea, in practice it doesn't seem to work very well because the detection is often unreliable or wrong, so a lot of the time you look at the speed values and know it is wrong yet again. Typical issues are that it detects the speed signs on minor roads branching off the main road you are travelling along and incorrectly assumes these apply to the main road, or where speed signs have another sign mounted on the same post above or below, it doesn't recognise the sign at all, or it misses signs.

With some better software it might be quite good, so wondered if this was something which had been improved over the last couple of years and could be updated?

[Chris Dance]

I have never heard that there are firmware updates for RSA. My experience with the system is the same as yours. 

[Cyker]

Well I have a brand new Mk4 Yaris and the RSA doesn't work much better than what you describe!

I'd say it's correct 70% of the time, but often misses signs or reads the wrong ones. Several times it's stuck with a 20mph limit indicator in e.g. a 40mph or NSL zone!

Another thing it seems to have particular trouble with is foreign lorries - I've frequently seen it claim the speed limit is 80mph in a 30mph zone 

What worries me is this is the system they are relying on for those speed limiters that they are introducing into cars next year; The tech is not just ready for it and it's going to cause more congestion and accidents...

I really disagree with a lot of these things - No device should take control away from the driver except maybe in certain life-threatening emergencies or if the driver voluntarily relinquishes control to such a system. It certainly shouldn't do it arbitrarily on a whim!

It's bad enough I had that problem where the car wouldn't accelerate due to a phantom collision warning, and left me straddling 2 lanes with on-coming traffic, creating a dangerous situation that would not have occurred in an older, supposedly less safe car!

[MyOpinionIsWorthless]

RSA is poor in implementation. Try driving behind a foreign lorry on the motorway and it will say you can drive 100 mph as it recognised the kmh on the back of the lorry. 

[Devon Aygo]

There are two TSB from Toyota for specific complaints:

BE-0017T-0217

Subject: Toyota Safety Sense P - RSA, LKA intermittent no operation under cold & humid conditions ( humid = condensated windscreen )

DESCRIPTION OF PHENOMENON Some customers may experience and report that under cold and humid driving conditions, the Road-Sign Assist (RSA) and the Lane Keep Assist (LKA) functions intermittently fail to detect road signs and/or the lane markers of the road. The symptom is due to a natural phenomenon that condensation can form inside the windscreen, temporarily obstructing the view of the forward recognition camera.

FIELD FIX INFORMATION Replace camera hood to the new design, fitted with heater fixed from Dec 2016 build, reprogramme forward facing camera assy

BE-00175T-TME

Subject: Road Sign Assist incorrect display of speed limit sign

Description of the phenomenon: Some customers may experience and report incorrect speed limit signs are displayed on the combination meter.

This is because of insufficient road sign database, no function comparing between vehicle speed and road sign value and inappropriate turn movement logic.

The incorrect display is shown in the following table.

Field fix is to reprogramme forward facing camera 

Fixed in production from March 2018

 

 

 

 

[AJones]

8 hours ago, Devon Aygo said:

BE-00175T-TME

Subject: Road Sign Assist incorrect display of speed limit sign

Description of the phenomenon: Some customers may experience and report incorrect speed limit signs are displayed on the combination meter.

This is because of insufficient road sign database, no function comparing between vehicle speed and road sign value and inappropriate turn movement logic.

....

Field fix is to reprogramme forward facing camera 

Fixed in production from March 2018

 

Thanks for that, that second bulletin looks like it might apply, my Prius was manufactured before March 2018 and it has made some of the errors shown - I have had the 90 mph speed sign come up and it does sometimes pick up and persist with signs with much lower speed limits despite them not applying and travelling a lot faster along main roads.

Any idea what the typical cost of getting the software update applied might be? Is it just a matter of quoting the bulletin ID to a Toyota dealer, or is there a lengthy process to getting the update booked? 

[MyOpinionIsWorthless]

14 hours ago, Devon Aygo said:

There are two TSB from Toyota for specific complaints:

BE-0017T-0217

Subject: Toyota Safety Sense P - RSA, LKA intermittent no operation under cold & humid conditions ( humid = condensated windscreen )

DESCRIPTION OF PHENOMENON Some customers may experience and report that under cold and humid driving conditions, the Road-Sign Assist (RSA) and the Lane Keep Assist (LKA) functions intermittently fail to detect road signs and/or the lane markers of the road. The symptom is due to a natural phenomenon that condensation can form inside the windscreen, temporarily obstructing the view of the forward recognition camera.

FIELD FIX INFORMATION Replace camera hood to the new design, fitted with heater fixed from Dec 2016 build, reprogramme forward facing camera assy

BE-00175T-TME

Subject: Road Sign Assist incorrect display of speed limit sign

Description of the phenomenon: Some customers may experience and report incorrect speed limit signs are displayed on the combination meter.

This is because of insufficient road sign database, no function comparing between vehicle speed and road sign value and inappropriate turn movement logic.

The incorrect display is shown in the following table.

Field fix is to reprogramme forward facing camera 

Fixed in production from March 2018

 

 

 

 

Thanks for this. I may turn RSA back on now

[Catlover]

Re the RSA, I find the system does not pick up all road side speed signs. Most of the missed ones are because the position of the signs are not in line of sight of camera, or the signs are overgrown with branches, or even unwashed with green algae making the sign difficult to see,           
The car camera picking up 100kmp signs on foreign lorries. I know I can’t travel 100 mph on any British road so it must be kph.  However if I took my car into Europe I know it would pick up kph signs and be right.

[PeteB]

When I bought my 2016 Prius Excel it had version 1 of Safety Sense and the RSA used the camera alone to detect speed limits.  As  others have said it did this very badly and I turned mine off, as did a number of other RSA V1 owners on these groups.

My 2019 RAV4 Excel has version 2 of the Safety Sense package, and the RSA is much more reliable, though still not perfect.  It's good enough that I have kept it activated.  This version uses a mixture of the SatNav database and camera to determine the limits and when it gets one wrong it usually corrects fairly quickly. 

After 2 years and over 16,000 miles I've still not been able to work out in my mind how it decides which to prioritise, and it was noticeable that one particular local road with a 70mph national speed limit which it almost always got right when I first got the car, started displaying as 40 mph after I updated the Maps about 6 months after delivery.  Further updates have failed to correct this, which seems rather odd.

I'm not sure how this works in models that don't have the SatNav, unless they have just enough of it to work with the GPS locator that's part of the E-Call emergency system.

RSA is slightly more useful with the Cruise Control on Safety Sense V2 cars as it allows the set speed to go directly to the displayed speed limit if the + or - button is held for a second ro two.  Of course, this is only useful if you don't mind using the speedometer speed, which for example means 60 mph on the speedoi is really about 57 mph.

[Cyker]

Ohhhh.... I wonder if that's why the RSA is so wonderfully inaccurate in my Yaris Mk4 - It doesn't have Satnav! So it's relying on the camera alone to spot road signs and boy does it get fooled easily!

I've also noticed it also just gives up sometimes - Often it insists the speed limit is 20mph, when it very very isn't, and after a while of me driving at e.g. 40mpg it just shows an unknown speed limit symbol 

I wonder if we'll see Mk4 Yarisusises with Satnav next year, to support the new enforced speed limiters they're putting into cars?