Yaris Hybrid 2020 TNGA - Hybrid System Malfunction

[Satsuki]

Has anyone else come across hybrid system malfunction in the new Toyota Yaris 2020 (mine is Launch Edition)? Last night while I was driving in a light rain in the motorway at 70mph all of the sudden the system alarm went off indicating hybrid system malfunction. Right after that a range of warnings lights and alarms apeared on the screen:

Hybrid system malfunction
Radar system malfunction
Pre-collision system malfunction
ABS break malfunction
Power steering malfunction

and a range of other warnings and lights that I can't remember.

Feeling the feedback from the steering wheel and acceleration pedal, I felt the car is genunely misbehaving and I am not in full controll of the car which was quite scary in that situation. Luckily I was the only person in the motorway at that moment and gently pulled to the side without attempting to break or anything and slowly stopped the car. Switched off the car and switched it back on and many warnings apeared on the screen. Then switch off completely and lock the car, wait for few minutes and switched back on again. The errors cleared themselves but the hybrid warning remained on the screen constantly saying 'Hybrid System Malfunction Visit Your Dealer'.

I am very surprised with what happened and I didn't expect this from Toyota and never experience such thing with Toyota before.

Searching online, I found few simillar issues reported in other forums for RAV4 but notting for the New Yaris. To me, it felt like the system was reset due to a power drop or something like that and it recovered itself but not completely sure. Just wanted to share my experience with you and see if anyone has seen simillar issue with the New Yaris. The earliest time that I managed to book with my dealer was next Tuesday, I will post the outcome here.

 

[scar]

1 hour ago, Satsuki said:

Has anyone else come across hybrid system malfunction in the new Toyota Yaris 2020 (mine is Launch Edition)? Last night while I was driving in a light rain in the motorway at 70mph all of the sudden the system alarm went off indicating hybrid system malfunction. Right after that a range of warnings lights and alarms apeared on the screen:

Hybrid system malfunction
Radar system malfunction
Pre-collision system malfunction
ABS break malfunction
Power steering malfunction

and a range of other warnings and lights that I can't remember.

Feeling the feedback from the steering wheel and acceleration pedal, I felt the car is genunely misbehaving and I am not in full controll of the car which was quite scary in that situation. Luckily I was the only person in the motorway at that moment and gently pulled to the side without attempting to break or anything and slowly stopped the car. Switched off the car and switched it back on and many warnings apeared on the screen. Then switch off completely and lock the car, wait for few minutes and switched back on again. The errors cleared themselves but the hybrid warning remained on the screen constantly saying 'Hybrid System Malfunction Visit Your Dealer'.

I am very surprised with what happened and I didn't expect this from Toyota and never experience such thing with Toyota before.

Searching online, I found few simillar issues reported in other forums for RAV4 but notting for the New Yaris. To me, it felt like the system was reset due to a power drop or something like that and it recovered itself but not completely sure. Just wanted to share my experience with you and see if anyone has seen simillar issue with the New Yaris. The earliest time that I managed to book with my dealer was next Tuesday, I will post the outcome here.

 

I had a very similar experience about 3 months ago. Came to a stop at traffic lights, pulled away and then the sound and light show started . The Dash cascaded through every alarm dwelling upon each one for about 3-5 seconds. It was naturally concerning but the car was driving fine. I was about 1/2 mile from home and parked it up on my drive. I think I had one warning light on that would not go out. ( As your last photo shows) Contacted my dealer and the car was checked out. They could see the events I described in the diagnostics but there was no recorded fault that would have triggered the alarms. The garage were keen to get hold of the car and send the report off to Toyota. 

The car has been in daily use since that event and it has behaved perfectly. Presently on 2600 miles

Whatever the cause was I believe it was just a one off. But if we don't tell Toyota about it they won't be able to establish a pattern and possible cause. Plus it needs the Toyota diagnostics to interrogate the fault memory and reset the warning sign.

The car is my wife vehicle and she is delighted with it.

Hope this puts your mind at rest.

 

 

[scar]

I would have liked to amended my post but there seems to be no edit facility.

After a rethink the car didn't drive fine at the time all the alarms were going off. I remember 2 things, 1st, the steering was behaving like lane departure was inputting to the steering wheel. 2nd was the power steering assist level altered, it went from almost none assisted to normal a few times.

This may be the "misbehaving" characteristic you experienced.

It would seem we both experienced the same fault.

Despite my years of engineering experience and enough certificates to paper a room turning it off and back on did not cure the problem. 😉

[Satsuki]

2 hours ago, scar said:

I would have liked to amended my post but there seems to be no edit facility.

After a rethink the car didn't drive fine at the time all the alarms were going off. I remember 2 things, 1st, the steering was behaving like lane departure was inputting to the steering wheel. 2nd was the power steering assist level altered, it went from almost none assisted to normal a few times.

This may be the "misbehaving" characteristic you experienced.

It would seem we both experienced the same fault.

Despite my years of engineering experience and enough certificates to paper a room turning it off and back on did not cure the problem. 😉

Yes, indeed. It looks like we have experienced a similar problem. I strongly believe it was some sort of power distribution issue to the controller unit that lead to the controller failing and going to a fail-safe mode. Driving 10-15 miles to get home after the incident, the hybrid systems were working alright and cycling the Battery without any problem. I think as the warning/failure was serious, it is designed to stay on until being check by the dealer despite it being already self-rectified. My feeling is that the dealer will clear the error and will not do much about it and that would be it.

As the car is pretty much brand new and under warranty, I stoped myself from looking into the problem. 😅 I am not a good mechanical engineer but when it's down to electrical/electronic problems I can interrogate every single electron 🕵️‍♂️ in the circuit boards until I find the guilty one. 😂

[Mikw]

These are similar warnings to what you get when the 12v Battery is low as well sometimes.

Please keep us informed of further developments.

[Catlover]

11 hours ago, scar said:

I would have liked to amended my post but there seems to be no edit facility.

Stephen, I thought that a couple weeks ago and Frostyballs put me right. You can edit after you submitted a post. Look at your post, top right corner, click on the 3 dots, one of the choices is edit.  Just edit your post then press the submit button as normal.

[TonyHSD]

Sounds like aircraft incident with all of those warning lights and malfunction 😅, without joke now something in connection with power supply of the 12v Battery, poor connection somewhere, loose ground or low voltage can trigger exactly these faults. Diagnostic it’s the first step towards investigating but a quick check of Battery terminals and ground cables in the engine bay might be helpful. Also if you interested you can buy yourself Carista obd 2 reader or similar, hook the car and do diagnostic and see what happens before visit Toyota dealer. I done recently on my car and was surprised how many possibilities gives me a simple diagnostic. 
Regards 

[scar]

14 hours ago, Catlover said:

Stephen, I thought that a couple weeks ago and Frostyballs put me right. You can edit after you submitted a post. Look at your post, top right corner, click on the 3 dots, one of the choices is edit.  Just edit your post then press the submit button as normal.

Thanks, my other forum has an “ EDIT” at the foot of the post, it also has a time limit on making alterations. Not so obvious here

[scar]

11 hours ago, TonyHSD said:

Sounds like aircraft incident with all of those warning lights and malfunction 😅, without joke now something in connection with power supply of the 12v battery, poor connection somewhere, loose ground or low voltage can trigger exactly these faults. Diagnostic it’s the first step towards investigating but a quick check of battery terminals and ground cables in the engine bay might be helpful. Also if you interested you can buy yourself Carista obd 2 reader or similar, hook the car and do diagnostic and see what happens before visit Toyota dealer. I done recently on my car and was surprised how many possibilities gives me a simple diagnostic. 
Regards 

I might as well get a suitable ob2 reader. We have 2 hybrids so I can see it getting some use.

[Satsuki]

On 2/4/2021 at 9:06 AM, TonyHSD said:

Sounds like aircraft incident with all of those warning lights and malfunction 😅, without joke now something in connection with power supply of the 12v battery, poor connection somewhere, loose ground or low voltage can trigger exactly these faults. Diagnostic it’s the first step towards investigating but a quick check of battery terminals and ground cables in the engine bay might be helpful. Also if you interested you can buy yourself Carista obd 2 reader or similar, hook the car and do diagnostic and see what happens before visit Toyota dealer. I done recently on my car and was surprised how many possibilities gives me a simple diagnostic. 
Regards 

Yup, it was a complere light and alarm show 😂. Yes, indeed, I suspect some issue with power itself or the connectors/grounding. My plan is to monitor the 12v powerline from few places and record the traces for sometime and see if there is any noise, drop or overshoot on it. Depending on how easy-access it would be, I might do the same with the high voltage Battery as well. I actually do have a couple of cheap OBD-II scanners lying around (not as fancy as Carista though) I just have to find them 🤦‍♂️.

On the bright side, I have switched on the car today and guess what, the error was cleared and there was no error on the panel anymore. I also drived the car for a bit and everything looked alright. Let's see what the dealer says on Tuesday.

[Satsuki]

Update...

Visited the local dealer on Tuesday morning and after waiting for a couple of hours or a bit more, they got back to me and told me that they cannot find anything wrong with my car 🤦‍♂️. Aparently they even drove the car for a while to see if anything goes wring with it. So they offered me two solution: 1- I leave the car with them and they give me a courtesy car for a while and they try to see if the car gives an error again. 2- I take the car and if the error appeared again, drive back straight to the dealer and they investigate it at that instance. So I decided to go with the second option and keep the car. As we discussed it's very likely to be some sort of power failure, so I will start searching for it myself and see if I can find anything...

[TonyHSD]

You picked the better option, the fault may never happen again therefore don’t worry too much and enjoy your new car. 👍🚙

[Chris Lindley]

My 2020 Yaris (70 reg) has just done a very similar thing.  Loads of warnings lights and alarms appeared on the screen:

Hybrid system malfunction
Radar system malfunction
Pre-collision system malfunction
ABS break malfunction
Power steering malfunction

Power steering went really heavy and brakes felt very soft. Very alarming.

Parked up and switched off. Left for 10 mins then restarted and seemed to drive home ok. Will be visiting Toyota dealer tomorrow

The only other strange thing it's done a few times is issue the 'BRAKE' alarm and slam on the brakes for no apparent reason, i'll mention that to them too 

[Mikw]

2 hours ago, Chris Lindley said:

My 2020 Yaris (70 reg) has just done a very similar thing.  Loads of warnings lights and alarms appeared on the screen:

Hybrid system malfunction
Radar system malfunction
Pre-collision system malfunction
ABS break malfunction
Power steering malfunction

Power steering went really heavy and brakes felt very soft. Very alarming.

Parked up and switched off. Left for 10 mins then restarted and seemed to drive home ok. Will be visiting Toyota dealer tomorrow

The only other strange thing it's done a few times is issue the 'BRAKE' alarm and slam on the brakes for no apparent reason, i'll mention that to them too 

And so it happens again. Would be very interested to find out what's causing this. Part of me thinks it's the 12v Battery dipping below a certain charge, but would be very intersted to see what the dealer says, let us know please.

[Liketodrive]

Hello- I had the exact same experience yesterday whilst driving 70 mph on the A3. An alarm extravaganza with everything malfunctioning and loss of control of steering, loss of power with acceleration and braking pedal being harder to engage. Phoned the dealer today- sadly they were not bothered as they’d not heard about the issue despite it being all over the internet and told me to call the breakdown service. 

[TonyHSD]

This can happen when hybrid Battery cooling vents had been blocked and there is not enough air flow to cool down the Battery or when there is a fault with electric pump 1 for inverter-converter coolant. , if the second happens very likely engine management light will be ON too. Best to get the dealer to run a diagnostic. They can not say not been bothered. You can Check your car manual for instructions what to do next. 👍

[Mikw]

11 hours ago, Liketodrive said:

Hello- I had the exact same experience yesterday whilst driving 70 mph on the A3. An alarm extravaganza with everything malfunctioning and loss of control of steering, loss of power with acceleration and braking pedal being harder to engage. Phoned the dealer today- sadly they were not bothered as they’d not heard about the issue despite it being all over the internet and told me to call the breakdown service. 

What did the breakdown people do?  Just out of interest what is your typical use pattern of the car?

[flash22]

Without the codes being read out of the inverter/ HV system there is not a lot you can do, its a safety issue so its down to the dealer/Toyota to sort it out

 

I take it recovery checked the 12v Battery connections are tight and secure ??

If there is a TSB on the issue it will be on toyota-tech (paid for service) €4 plus vat an hour

Just looked up the HV recall its for 3400 cars 2018-2019 so the gen3 yaris - the gen 4 runs a newer Hybrid system and different engine - if there was a known issue with the Gen 4 it will be known about but due to lockdown the cars may have not been in use

Quote

Defective soldering may cause a transistor to separate from the circuit board of the DC-DC converter. As a result, the auxiliary battery may no longer receive power from the DC-DC converter. If the auxiliary battery is discharged to a certain level, the hybrid system could shut down, resulting in loss of motive power. Loss of motive power while driving could increase the risk of an accident.

The Toyota Yaris models affected by this recall were manufactured between 06 February 2018 – 02 April 2019;

DIR_TME 19SMD062

 

[Trulivar]

Hi, this problem happened to me exactly the same, doing about 70mph on M62, loss of braking power and steering went lumpy. Called for assistance, but after about 10 minutes the car rectified itself. The A A man said that there was no warning on the diagnostics. My car has 2550 miles on the clock and goes in to the garage on Wednesday but I imagine they will find nothing.  My question is has anybody had this happen again?

[Mikw]

8 hours ago, Trulivar said:

Hi, this problem happened to me exactly the same, doing about 70mph on M62, loss of braking power and steering went lumpy. Called for assistance, but after about 10 minutes the car rectified itself. The A A man said that there was no warning on the diagnostics. My car has 2550 miles on the clock and goes in to the garage on Wednesday but I imagine they will find nothing.  My question is has anybody had this happen again?

When you say it rectified itself, did you have to turn it off and on again?

[scar]

I posted on the 3rd feb in reply to the original poster. My wife’s Yaris had this issue with me driving and my wife in the passenger seat.

No fault codes, nothing to see.  I got mixed feed back from the dealer. Depends on who you speak with. 

Statistically the problem experienced by forum members warrants Toyota interest. Rather than the dealerships attitude.

This fault has never replicated itself.  My wife’s Yaris still has an issue ( mentioned in another post by myself)  with an intermittent high frequency sound produced under certain conditions. As it’s intermittent and they won’t accept a video and sound recording of the noise I’ve moved no further forward in getting this issue resolved.

My wife loves the Yaris to drive, as do I. But as a retired engineer with more experience than the Toyota staff I have spoken with there are doubts in my mind about reliability. 

If this problem occurred on a smart motorway, I would be thinking of getting rid of the car. Confidence would be lost, all the garage would say “well there’s no data available on the fault” . Yes your dash cam might have recorded the audible sounds of the alarms but that’s not good enough for us.

Sad but true.

Just to make it clear when the fault happened the only residual fault displayed was the dash warning about a fault with the hybrid system. This had to be cleared by the garage. No other fault data was shown when the diagnostic system was interrogated. 

 

 

 

[Trulivar]

14 hours ago, Mikw said:

When you say it rectified itself, did you have to turn it off and on again?

I pulled into a service station which was almost as soon as the Blackpool illumination happened. I switched off the car and contacted Toyota. They told me to start the car to see if the engine would start, when I started the car it still had the malfunction but drove in EV mode in the car park. He then told me to wait for the AA man. I was concerned about leaving the car because it said Smart Entry might not be working, and I decided to move the car to a better place in the car park, that was when the problem resolved itself. The AA man could not find anything wrong on his diagnostic check. I now wonder when this may happen again.

[emin-j]

As mentioned above check Battery terminals are tight , the 12v Battery condition is important on the hybrid models many cars are left in storage for some time and Battery quality suffers, also check 30amp dome fuse is secure in the fuse box.

[Trulivar]

Hi All, good news just been contacted by my Toyota Service Garage manager and told that Toyota know about this problem and have a software fix. Hopefully this is being done Tomorrow. The service manager said he had not done this before or knew about this. I don't know if they plan a recall but suggest getting on touch with your dealership to find out more. Hooray

[Mikw]

6 hours ago, Trulivar said:

Hi All, good news just been contacted by my Toyota Service Garage manager and told that Toyota know about this problem and have a software fix. Hopefully this is being done Tomorrow. The service manager said he had not done this before or knew about this. I don't know if they plan a recall but suggest getting on touch with your dealership to find out more. Hooray

Good news that they know about the problem, hopefully a recall will be done. Aside from the 12v Battery going flat (and that can be avoided) the Hybrid system malfunction is the other main worry with these cars.