"Check BSM system" & warning triangle - 63 plate IS300H

corpjones · January 15, 2021

Hi All

I have a 63 plate IS300H Premier, a few days ago I popped into the grocery store, on the way back when pulling into the driveway, I randomly got this error "Check BSM System" with a warning triangle, I turned the car on and off again and have driven a couple of times since then and it has not reoccured.

My car is still under a approved used warranty, should I be raising this? It looks to be relating to the blind spot monitoring but I'm not 100% sure where the sensors are located in this car, due to covid I hardly drive it so the car is pretty clean, purchased it from a main dealer a few months ago and has about 62k miles with full Lexus history.

I'm hoping its a normal error people on here get from time to time, if not I may have to do some more digging 🙂

Thanks

LenT · January 15, 2021

The Manual states that this warning relates, as you suggest, to the Blind Spot Monitoring system. As far as I can see, the only recommendation is to refer the car to a Dealer!

The sensors, I believe, are located in the wing mirrors and along the rear of the car.

As it’s still under warranty I would be inclined to do that ASAP.

Edited January 15, 2021 by LenT
More info

Inazone · January 15, 2021

The fact you mentioned you hardly drive your car since covid, I'm going to take a wild stab at the problem, and point you to the auxiliary Battery in the boot. There's a good chance the Battery is on it's way out. All sorts of error messages pop up when the Battery starts to fail.

Hemlag02 · January 16, 2021

I can’t help with the error message but earlier this week the dashboard on our CT was lit up like a Christmas tree and car would not start. Called the AA out, fault diagnosed to a flat Battery as the car currently is not being used as much as normal due to Covid (was doing a 250 mile, mainly motorway trip at least once a week). I also contacted my Lexus dealer who advised the following

Run the car in ready mode for an hour, even longer if you can and probably once a week or once every 2 weeks to keep it charged up!

I hope this helps.

paulrnx · January 16, 2021

If it’s under warranty surely the answer is to get it booked in to a dealership to get it checked out. I would.

200h · January 16, 2021

take a photo of the message on the dash and email it to your dealer so there's a log of it happening whilst under warranty

and get your car booked in for them to look at it,

maybe contact lexus uk and inform them so they are also aware in case the dealer

can't get your car booked in until after your warranty has expired

you should still be covered then

LenT · January 16, 2021

7 hours ago, Hemlag02 said:

Run the car in ready mode for an hour, even longer if you can and probably once a week or once every 2 weeks to keep it charged up!

Not really the ideal solution, for several reasons. For example, it's not very environmentally friendly. If the car's on the public highway, and unattended, it would be illegal. And some say one hour barely compensates for the current used to start the vehicle.

A better solution is to buy a trickle charger. I bought a CTEK and fitted sets of accessory plug-in connector leads to the Battery posts of both our cars. Now all I have to do is plug the CTEK connector to the installed leads, turn on the CTEK and leave it overnight to do its thing.

ColinBarber · January 16, 2021

13 minutes ago, LenT said:

And some say one hour barely compensates for the current used to start the vehicle.

The OP has a hybrid vehicle, no current is used from the 12v Battery to start the vehicle.

LenT · January 16, 2021

48 minutes ago, ColinBarber said:

The OP has a hybrid vehicle, no current is used from the 12v battery to start the vehicle.

Thanks for that info, Colin. Hybrids are foreign territory to me, I must admit. Lexus tend to loan me one when mine’s in for service and, to my shame, I have managed to stall them on a couple of occasions! However, I think the other points are still valid - and two out of three ain’t bad!

But mainly I’m suggesting that in a low mileage situation and especially in winter, an easy-to-use trickle charger is a sound investment.

At least, that’s been my experience.

ColinBarber · January 16, 2021

6 hours ago, LenT said:

But mainly I’m suggesting that in a low mileage situation and especially in winter, an easy-to-use trickle charger is a sound investment.

At least, that’s been my experience.

Agreed. I think I've only done around 300 miles in my vehicle since April and I leave it permanently connected to a trickle charger. But I guess not everyone has the convenience of electrical power near the vehicle.

But I think I'd rather run an extension lead to my vehicle and use a charger once a week for a few hours rather than starting up the vehicle and sitting in it for an hour.

LenT · January 16, 2021

1 hour ago, ColinBarber said:

But I guess not everyone has the convenience of electrical power near the vehicle.

That’s a whole new topic you’ve opened up there!

corpjones · January 16, 2021

Thank you for all the replies, if no ones seen this error guess its not that common so i'll report it to the dealer and take it in when Covid figures are looking a bit better as it does not seem like a urgent issue (light has not since that one time).

I do drive the car for 10min every week just to keep the Battery topped up, i've not had any issues "starting" the car but hard to say what condition the smaller Battery is in, longest stretch its been without starting is 10 days but it did fire up without issues.

My only concern is, with my old car (E Class) even though it was under warranty they charged me diagnostics as they could not find a issue so the dealer could not claim under the Mercedes warranty, I was a bit worried about the same happening here if no fault found or are Lexus generally pretty good?

matt8 · January 16, 2021

36 minutes ago, corpjones said:

My only concern is, with my old car (E Class) even though it was under warranty they charged me diagnostics as they could not find a issue so the dealer could not claim under the Mercedes warranty, I was a bit worried about the same happening here if no fault found or are Lexus generally pretty good?

It's not your job to identify the problem, only to demonstrate the symptom.

If you can show the problem (in this case a message on the dash), it's surely up to them to find the issue.

I think Mercedes did you over there. Unless you weren't able to prove any problem or show them an error.

I doubt you'll have this issue in your circumstance, but if you did, I wouldn't be backing down!

corpjones · January 16, 2021

I got the money back from Mercedes in the end but it took a lot of back and forth, I was picking up the car at lunchtime during work so had to pay it to make it back in time, Mercedes service was poor most of time in my experience but i've heard Lexus is a lot better but once bitten twice shy 🙂

I've taken a photo of the error message on dash in any case so I will show them that.

OldTrout · January 16, 2021

5 hours ago, LenT said:

Thanks for that info, Colin. Hybrids are foreign territory to me, I must admit. Lexus tend to loan me one when mine’s in for service and, to my shame, I have managed to stall them on a couple of occasions!

Len,

How do you stall a hybrid?

John

LenT · January 16, 2021

11 minutes ago, OldTrout said:

Len,

How do you stall a hybrid?

John

I’ve no idea John. Which probably explains why I did it again, months later! I can only think that being a stranger to the hybrid I thought it had stalled and, being at the head of a queue at traffic lights, did the wrong thing. Whatever that was!

But whatever it was, I haven’t done it again.

OldTrout · January 16, 2021

50 minutes ago, LenT said:

I’ve no idea John. Which probably explains why I did it again, months later! I can only think that being a stranger to the hybrid I thought it had stalled and, being at the head of a queue at traffic lights, did the wrong thing. Whatever that was!

But whatever it was, I haven’t done it again.

The engine is often not running when you stop but that doesn't mean it has stalled. When you press on the accelerator the car will move forward by the electric motor and depending on lots of things the ICE will assist sooner or later.

John

LenT · January 16, 2021

38 minutes ago, OldTrout said:

The engine is often not running when you stop but that doesn't mean it has stalled.

Yes, I think that must have been it. Note to self: must pay attention!

corpjones · March 1, 2021

Just to update everyone, took car in and there were some errors suggesting communication was lost between between sensors, they reckon its the 12V Battery.

They kept it over 2 days and measured the 12V Battery which apparantly showed the level dropping to below a acceptable level, the batteries have a 3 week lead time so just waiting for it to arrive so they can fit it for me.

This started happening 3-4 months after I purchased it as a approved used car, it has been used at least once a week (to keep the Battery topped up) so I suspect the 12v Battery was faulty when I purchased the car, would you guys try and get the Lexus dealer I purchased it from to pay for the Battery?

Its not the end of the world if I have to pay for it but just a bit surprised it went so soon after I purchased the car, just thought i'd get some opinions 🙂

matt8 · March 1, 2021

1 hour ago, corpjones said:

Just to update everyone, took car in and there were some errors suggesting communication was lost between between sensors, they reckon its the 12V battery.

They kept it over 2 days and measured the 12V battery which apparantly showed the level dropping to below a acceptable level, the batteries have a 3 week lead time so just waiting for it to arrive so they can fit it for me.

This started happening 3-4 months after I purchased it as a approved used car, it has been used at least once a week (to keep the battery topped up) so I suspect the 12v battery was faulty when I purchased the car, would you guys try and get the Lexus dealer I purchased it from to pay for the battery?

Its not the end of the world if I have to pay for it but just a bit surprised it went so soon after I purchased the car, just thought i'd get some opinions 🙂

If you don't ask, you won't get.

I know what I'd be asking for.

What dealer did you buy it from?

paulrnx · March 1, 2021

2 hours ago, corpjones said:

Just to update everyone, took car in and there were some errors suggesting communication was lost between between sensors, they reckon its the 12V battery.

They kept it over 2 days and measured the 12V battery which apparantly showed the level dropping to below a acceptable level, the batteries have a 3 week lead time so just waiting for it to arrive so they can fit it for me.

This started happening 3-4 months after I purchased it as a approved used car, it has been used at least once a week (to keep the battery topped up) so I suspect the 12v battery was faulty when I purchased the car, would you guys try and get the Lexus dealer I purchased it from to pay for the battery?

Its not the end of the world if I have to pay for it but just a bit surprised it went so soon after I purchased the car, just thought i'd get some opinions 🙂

Any fault on a used car that becomes evident within six months of purchase is deemed to have been there at purchase. I think this is the gist of the law in this area. I’d research and then talk to the supplying dealership and quote the exact wording back to the dealership and ask for them to replace the Battery free of charge. They may not agree and you’d have to play hardball to get them to do it. A compromise might be that you agree to pay cost for the Battery and they fit it for free which might be say 40-50% of the normal fully fitted price.

corpjones · March 2, 2021

20 hours ago, matt8 said:

If you don't ask, you won't get.

I know what I'd be asking for.

What dealer did you buy it from?

It was a Steven Eagle Lexus branch

corpjones · May 18, 2021

Battery has now been replaced, the error stopped occuring on its own for some reason (maybe they charged the 12v Battery?) but i'll keep an eye on it, i've driven for a couple of hours and so far it looks like i'm getting 3mpg more since batt replacement.

A lot more driving is needed to see if this is consistent but a interesting observation for now.

Robert Wilson · October 3, 2021

I just got the same warning for(I think) the first time in about 4 years on a 64 plate is300. Stop, start, all good no warning again... Will keep an eye. Apparently it's BSM=Blind Spot Warning system. So, even if it does recur, it's not a STOP, DON'T DRIVE type warning. Which is nice. But hopefully all's well with you too.

corpjones · October 3, 2021

54 minutes ago, Robert Wilson said:

I just got the same warning for(I think) the first time in about 4 years on a 64 plate is300. Stop, start, all good no warning again... Will keep an eye. Apparently it's BSM=Blind Spot Warning system. So, even if it does recur, it's not a STOP, DON'T DRIVE type warning. Which is nice. But hopefully all's well with you too.

If it helps mine was resolved by Lexus replacing the 12v Battery so that was the cause, was easy for them to test the Battery too so might be worth doing?