Faulty 12V batteries warranty replacement in Toyota Yaris Mark 4 

Thanks for the comment. I am glad the video was helpful 👍

Thanks for the comment and I am glad my videos about the 12V battery issue have been helpful. My new car was OK for 10 months with 6,000 miles on the clock and then it failed to start after one day without use!!! I think your car and 12V battery are still new enough to keep starting even after a week or more without use. Your "February" car will be 10 months old in December when the weather will be a lot colder which obviously puts a bit more strain on the 12V battery. I am really sorry to say this but I think December / January may be the time when you experience the problem. You obviously have got AA included for the first year as part of the purchase. In my experience they turned up very quickly and got my car going but they then recommended that I drive it straight to the dealer who then recharged the battery overnight and gave me the car back the following afternoon. The AA get the car going quickly but the real inconvenience was being without a car for most of 2 days. I would suggest that you buy a NOCO GB20 jump starter which will allow you to get the car started within a couple of minutes. You can then drive wherever you need to go. The NOCO will not recharge the battery ... my suggestion is to leave the car in READY mode for 60 minutes to recharge the 12V battery from the main traction battery. A NOCO GB20 is under £100 and it means that a failure to start will not be too much of an inconvenience. I feel terrible telling you to expect you new Yaris Cross to fail to start ... I was aware of the problem but did not think it would happen to me because I drive about 8,000 miles per year and only my car only occasionally has a day parked without use ... but it did happen to me so I am sorry to say that I think there is a good chance that it will happen to you. I also know from talking to my dealer, the number of comments on my videos and online discussion in Toyota Owners club and elsewhere that it happens to a LOT of Yaris owners. www.toyotaownersclub.com/forums/topic/217673-12v-battery-maintenance-issues-etc/ Its not what I expect from a Toyota ... my Yaris is the best car I have ever bought but also the worst car!

Thanks for the comment. Glad you enjoyed the video. When you get a reply from your dealer please post a comment so that we can see how the rollout of the new procedures and test equipment is proceeding. Thanks

Have you heard anything from your Dutch dealer? I am Dutch too and I will make a service appointment with my Dutch dealer tomorrow and will ask them the same question as you did. As soon as I have any information about this I will post this here. @Helpful-Stuff: Thanks for creating these great videos. My Yaris is from April 2021 and experience the same problems with the 12V battery as you do when you don't drive that much. I thought I was the only one!

@ErikMPNL Thanks. I am glad my videos are helpful - if only to find out that you are not the only Yaris owner experiencing the 12V battery problem! I hope that @erikderuiter7475 is able to give us an update. Good luck when you talk to your dealer tomorrow. I hope that the Poland test equipment, procedures and warranty change has rolled out to The Netherlands 🤞 ... and you are able to update us with a post on this thread. 👍

I have spoken to my Toyota dealer (Hilversum, NL) yesterday. I wasn't able to figure out whether they have the same new ‘Poland' procedure concerning the 12V battery problems. The answer was rather vague (as I expected): you don't drive much and this often leads to a flat 12V battery with ANY hybrid car, not specifically Toyota. My monthly average is about 160 km (approx. 100 miles). I don’t have any experience with hybrid cars of other brands. For example: do Suzuki or VW hybrids have the same 12V flat battery problems? I don't know. But my first thought was that Toyota likes to downplay their problem by saying that other (hybrid) brands have this problem too. I have to say that my dealer replaced my 12V battery with a new one (under warranty) in January 2023, together with a DCM (Direct Communication Module) software update: the old software drained the 12V battery too much. They did this after I told them that my 12V battery was dead every 2-3 days especially in the cold months November, December 2022. (My Yaris is from April 2021 and I bought this car from my dealer in August 2022.) Unfortunately, this lead to a flat battery once every 10-12 days. Better, but still far from great. This was the moment (mid 2023) that I decided to buy a jump starter myself (costs about 130 euro). I was fed up calling Toyota Services and waiting for them to arrive at my house and recharge the battery. Although I now was able to help myself out, and saving time by jump starting my car when needed, it still remained annoying. Nowadays I leave the car in READY mode once a week for about 40 minutes. The downside of this is that I have to leave the smartkey inside the car: the smartkey has to be near or inside the car for it to be in READY mode. I lock the cardoor with the small metal key (which slides into te smartkey) and go inside my house to do other stuff during those 40 minutes. This is because I don’t have a direct view from my home on the parking place nearby, and I don’t want to sit and wait for 30-40 minutes inside the car. I’m doing this routine now for about 2 months or so and it seems to work. I haven’t had a flat 12V battery since I started this routine. Returing to the topic of this video: no clear answer from Toyota whether there is a new procedure as shown in the video. I’m hoping that other viewers of your channel (@Helpful-Stuff) can give new information about this procedure in The Netherlands and other countries in Europe.

Thanks for the update after the discussion with your Toyota dealer. Your dealer is correct there is a generic problem with all Hybrids from all manufacturers. They all use a small 12V battery because there is no starter motor which requires a lot of current. A hybrid only needs to start the computers so it requires very little current but a good voltage. A small 12V battery will provide the voltage required and save weight. However, the problem for all hybrids happens when you park the car for a long period ... difficult to be precise but 10 days or more. The most likely way that people come across this problem is when they go on holiday and park in an airport car park for 2 weeks. They return from holiday and the 12V battery is flat and the car will not start. Modern cars use a lot more current when parked than a car built 20 years ago. While on holiday this small current over many days parked drains the small 12V battery. So that's the generic problem with Hybrids but the specific problem with the Toyota Yaris is different. My 2022 Yaris Mark 4 was only 10 months old and had done around 6,000miles when it failed to start after just one day without use. My car is definitely not a low mileage car - it does about UK average mileage - but it failed after 1 day without use. For comparison I bought a new Yaris Mark 3 in 2018 and it started reliably until I upgraded to the Yaris Mark 4 at the end of 2022. I owned the Yaris Mark 3 all through COVID lockdowns where it was only getting used once per week for a 20 mile round trip to the supermarket ... but it started reliably - I never had a problem. There is something wrong with the 12V system in the Yaris Mark 4 and it looks like it is a duff battery from Mutlu. I think that the fact that my car failed to start means that low mileage owners of a Yaris Mark 4 are a LOT more likely to experience a failure to start. When I was Googling to check if other Hybrids suffer from flat 12V batteries it is very obvious that there are an enormous number of people experiencing the 12V problem with the Yaris and a much smaller number of people experiencing the problem with other manufacturers. Toyota have now changed my 12V battery and I now monitor the voltage daily ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0nYdnNVgvJI.html This video was made with my old battery. The voltage with my new battery is about 0.5V higher than the old 12V battery. This means that my old battery had been damaged by just one failure to start. Low mileage drivers like you will experience multiple failures to start. Each failure to start damages the 12V battery which means that you are even more likely to get another failure to start ... its a downward spiral until you get to the situation that you were in where you have to jump start the car every few days. I think Toyota and the dealers use the generic Hybrid problem as an excuse to blame the customer when they should be looking at their own design and specification of the 12V system. This was why I was so interested to read in the Polish news article that Toyota Europe accept that there is a problem with the battery. I think you are doing the right thing with your 40 minutes running in READY mode. Like you I don't want to just sit in the car so I wash my car while it is in READY mode each week. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Ch-L0JbbQUg.html I recommend watching this video because it includes a tip to reduce the amount of time that the petrol engine is on while the car is parked in READY mode so it will save you money! I hope the weekly wash & charge will mean that I do not suffer from another flat 12V battery ... but if I do ... or if my daily voltage readings drop below 12V ... I am going to go to a non-Toyota garage and ask them to change the 12V battery for a Yuasa battery. From what I have read these are a much better battery than the Mutlu battery specified by Toyota. I have owned Toyota's since 2005 ... my Yaris Mark 4 is both the best car I have owned but unfortunately it is also the worst car I have ever owned ... and the last Toyota that I will buy.

I was hoping that this video would get a lot more views and also comments from people who have recently visited their dealer with the 12V battery issue who would be able to say whether or not the new test equipment and procedures have been rolled out across Europe. There is one comment from somebody who has had their 12V battery replaced under warranty ... but I don't want to draw conclusions from a single warranty replacement. Interestingly they were told that they must do at least 90 miles per week with the new battery .... which is about 4,600 miles per year. Toyota GB agreed to change my 12V battery about a month ago. I spoke to my dealer and they said my battery was being changed for the "same spec battery" but he did not say anything about the manufacturer of the battery. So it could be the same spec battery but from a different manufacturer. However, he did say I should continue with my 12V battery management... - solar trickle charger not every day but regularly and definitely if the car has one or more days parked and not used - weekly 60minute recharge which I do while I wash my car ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Ch-L0JbbQUg.html - monitor the 12V battery voltage using a voltmeter plugged into the acessory socket ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0nYdnNVgvJI.html - NOCO GB20 kept behind the passenger seat ... just in case My new battery is ALWAYS above 12V when the car is in ACCESSORY MODE ... typically about 0.5V higher than my old battery. So it seems pretty clear that my old battery had a significant performance drop off even though it was only 10months old and had been driven just over 6,000miles (so it was not a low mileage car) and is therefore getting recharged regularly. If I get problems with this new battery then I am going to go to Halfords because they will fit a 45Ah battery into a Yaris. I will have to pay for it ... but its not an enormous amount of money and I think this slightly bigger capacity battery will give me much more confidence that the car will always start. My Yaris is both the best car I have ever owned and at the same time the worst car I have ever owned!!!! Once it has started I absolutely love the car and would strongly recommend it. The weekly car wash and recharge is no problem for me ... I would wash the car weekly anyway. I now only use the solar trickle charger when the car has a day or more off .. which does not happen very often. All other aspects of the car are so good I am living with the 12V battery problem. I would not say I am happy but I have learnt to live with it. The big question is ... if I was in your situation would I buy a 2024 facelifted Yaris?... I think before paying my deposit I would ask the salesman: (1) Is the factory fitted 12V battery still the Mutlu 35AH battery? If it is then if you buy the car then you will need to manage the 12V battery and you need to decide if you want to buy a car where you need to manage the 12V battery. I believe that the Yuasa 12V battery is a much better battery and this may be the factory fitted battery in the new Yaris. (2) Ask the salesman for a written confirmation that if the 12V battery fails during the first 12months then your dealer will change the 12V battery without wasting time doing a battery test ... they will just change it no questions asked. I think you will struggle to get this ... or they will try to say this will be covered by the warranty. From my experience with a 10month old car I can tell you that I really struggled to get a new 12V battery under warranty. However, if the Toyota Poland testing equipment and procedures have rolled out in the UK then warranty claims may be much easier.

@@Helpful-Stuff Thanks for the response, never imagined it would be so detailed! Seems bit unrealistic to have to baby sit the 12v battery especially for a new car, even so, from Toyota which is renowned for their reliability! Will wait a bit since the facelift seems quite recent and there hasn't been any reports of it online. Hope you get yours resolved, will be following this closely.

which volt tester you got?

My car's battery was flat after ONE day without use !!! I have been putting a solar charger on almost every day ... doing a weekly 60minute car wash & charge ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Ch-L0JbbQUg.html ... and I have a NOCO GB20 in the car just in case. I also have a voltmeter that I bought on eBay plugged into the accessory socket. This vid shows how I use it to keep an eye on the 12V battery voltage ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0nYdnNVgvJI.html

@@Lynch___ I have the noco gb20, the aa solar charger and same voltage tester in the comment -below- above. The solar charger is useless on an unhealthy battery which mine is by now as not yet 18 months old and nearly 3500 miles on the clock. The car hasn't started for me at least a half-dozen times in this time. At least!

I agree, a simple solution would be for the onboard computer to detect the battery voltage, and trickle charge it from the Hybrid one (which is where it charges from apparently) when the car is parked and off.

@BrianEcclestone That would not solve the root cause of the problem which is that the factory fitted 12V battery is a very bad battery. Your solution to charge from the traction battery when the car is parked and off will result in the 12V battery degrading more and more until it holds almost no charge and then the main traction battery will be continuously charging the 12V battery when the car is off. Consequences of this may be even worse than the 12V battery having no charge. Toyota's current design of charging the 12V battery from the main traction battery when the car is on and in READY mode is the correct design when the 12V battery is a high quality 12V battery designed for use in a Hybrid. This design worked in my Yaris Mark 3 Hybrid which started reliably for 5 years even during COVID lockdown when it was only used once per week. I then bought a Yaris Mark 4 and it failed to start after 10 months and ONE day without use. My experience shows is not the basic design that is wrong ... it's a bad battery and Toyota need to fix the bad battery ... which it is (hopefully) doing. I have Googled and found people complaining about Hybrids from all manufacturers failing to start because the 12V battery is flat. However, the number of complaints about the Yaris Mark 4 failing to start are significantly higher than other cars because of the bad factory fitted 12V battery. Because any Hybrid can suffer from a flat 12V battery I think Toyota should add: (a) 12V battery voltmeter on the dashboard display (b) 12V battery voltmeter in the MyToyota app with notifications if the voltage drops below a threshold when parked (I think the MG app does this) (c) 12V Reset button as in Kia and Hyundai Hybrids which prevents the 12V battery from going flat ... explained in this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-3k7SSJecDUg.html And Toyota sales should be honest with customers and explain about 12V battery management in a hybrid ... and suggest that the customer buys a solar trickle charger if they expect to leave the car parked and unused for a week or more.

Can you leave a comment to let everybody know what your dealer says. Thanks 👍

I think dealers are getting tired of Yaris Mark 4s with flat batteries. They will deny that the battery is the problem and blame the owner for not driving the car enough. Somebody left a comment that Toyota Leicester are charging £144 to recharge the battery overnight and test it. If the battery fails the test then you do not have to pay the £144 charge. This is disgraceful profiteering by the dealer from a Toyota decision to use a bad 12V battery from a Turkish supplier called Mutlu. My brand new car failed to start when only 10 months old after one day without use. My dealer initially told me that it was my fault because my regular driving was not charging the 12V battery. I do about 8,000 miles per year - that should be enough to keep the battery charged!!! They put the car on charge overnight then left it for a few hours to see if it lost charge. It didn't so they handed the car back to me saying that I had a healthy 12V battery. I complained to Toyota GB cr@toyota.co.uk and 5 months later I did get a new 12V battery. I have purchased a voltmeter that plugs into the accessory socket and I monitor the voltage in accessory mode. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0nYdnNVgvJI.html The new battery is reading 0.5V higher than the old battery. The old battery had been degraded when just 10 months old. It wasn't totally damaged but it certainly was not 100% healthy. So unless the dealer is using the new test equipment and procedures that have been rolled out in Poland do NOT trust the dealership 12V battery test. My 12V battery passed the test but was degraded and should have been replaced immediately. Its also worth pointing out that if Toyota Leicester were my dealer I would have had to pay £144 - what a rip off!!! My battery has been replaced with the same spec battery that failed when my car was only 10months old. I am expecting the battery to fail again in 10 months. When it does I am not taking it to a Toyota dealer to have the same bad Mutlu (Turkish) battery fitted again. I am taking it to somebody who will fit a Yuasa battery which, I am told, is a much better battery.

I believe that Mutlu batteries are made in Turkey.