Steven Lockey

@Hangie I thought that at first as well, but reading around it seems that the Lexus will keep trying to use the hybrid battery unless it thinks it is totally dead. If it just thinks a few cells in the pack are dead, it will throw up loads of warnings but the car will still function normally, including continuing to try and use the battery pack. When I said 'instantly starting' I was meaning when I put it into P, pressed the brake and hit the power button again. Not that it instantly started the engine as soon as I moved the shifter. Apologises, I should have been more clear. If it was a transmission pump issue it should be showing an error and should automatically shift to petrol only mode which doesn't seem to be happening so I don't think this is the cause. Also from what I've read as soon as this error is detected, it puts the car into some limited mode. If it was an inverter issue, well, I actually used to work as an electronic engineer and this would be one very strange inverter issue! Also this should also output a specific error code which isn't been produced. This is why I was thinking its a battery error as the old cells can sometimes produce a unreliable current which can spike and drop and I was thinking that might be the issue. These issues often appear intermittently (just like mine) and tend to temporarily resolve themselves (just like mine). They can also overheat badly when you attempt to charge them, my other thought was as I was letting off the gas, the power was been switch to charge the hybrid battery, causing a temperature spike, and the computer sees this and shuts the car down to prevent a possible fire? Hmm, just read elsewhere that a battery overheat will cause the car to shut off entirely like mine is doing and is also producing no error codes other than the normal battery failures. It looks like we may have a winner! It makes a certain amount of sense because if its a single cell that is overheating, then by the time I've pulled over to restart the car, it's cooled down sufficiently for it to not moan again. Seems most of the other hybrid systems on the car will flag a specific code if they are overheating but the battery doesn't. If anyone know any different, please let me know! 🤞 this is the issue and the new battery will sort it! On that note however, does anyone know an easy way to clean the hybrid battery fans? I took a look at the fans on the behind the back seats and they are quite dusty but I couldn't see any easy way to get the covers off for access.

Oh and I did try driving it in 'S' mode and it did the same thing so not that. I did think it might be the battery overheating as the battery fans do run like crazy all the time. Maybe the air-vents are a bit blocked and combined with the battery been on the way out this is causing it to overheat? Would battery overheating cause a error code and the car to shut down? This would make sense as a fire prevention measure, but I would have expected a different error code to show up if there was an overheat problem.... but I can't see one listed for it so it might just display the battery error code on an overheat.

Thanks Lwerewolf, but I don't think this is the case here. I believe you should see an error code if this is the case (p2797) which I don't get. Also from what I've read, if this happens, the car drives normally on the petrol engine but just refuses to use the hybrid system. In my case, when the car is working, everything seems to function perfectly including the hybrid system which run normally both accelerating using the hybrid and the regenerative braking. I'd be very surprised if there was an error with the pump but it wasn't putting out a error code for it as from what I understand it would output that code as soon as it saw the transmission oil pressure been too low. @Farqui Yep, I can't see any other faults at all other than the battery and I've done every test I can think of sort of taking it an actual engineer. So guess I'm going to have to cross my fingers and hope I'm not about to waste a load of cash! I'm generally quite good at working out where the problem lies with the car, I'm just absolutely terrible at fixing it! 🤣 Really hoping it is just the battery as everything else I try to test seems to come up good! Knowing my luck, I'll spend thousands trying to fix it and it will turn out to be a loose wire somewhere!

Many thanks Farqui, I'll have a look to see if the previous owner did the hybrid health checks on this car. I'm guessing he didn't but I can but hope!

Does anyone know where I can find any information on this 15 year warranty? I've got a load of paperwork that came with the car at home so I think it has had a yearly service. I've not seen this before, I thought as the car was 12 years old it would be well out of warranty! More so with 178k on the clock!. If it is in warranty that would make me a very happy bunny! Thanks

Its possible but I think that would be very unlikely. Even if there was an unknown error I would expect the car to produce an error code if it was the generic 'something went wrong' code. I'd be very surprised if it was an inverter issue since when the car is working it accelerates perfectly(hybrid and petrol) and I can see the regenerative breaking is also functioning fine. The hybrid kicks in when accelerating normally. From what I understand if there were issues with the other parts of the hybrid system I should be seeing other error codes been produced. Also if it was an inverter issue I would expect the issue to happen more when the inverter is under strain than anything else but I can quite happily put my foot down and the hybrid system functions perfectly. I can also see it regenerating power at it's maximum listed rate under heavy breaking. Given a few people have said this issue can be caused by the battery, I'm kinda betting on that. I've only looked up the error code on my OBD reader so far and cross-referenced that with Lexus. I've downloaded techstream and have ordered a OBD to USB cable but until that arrives can't do much more.

Hi, Thanks for the replies The dealer sold it as good but turned out the hybrid battery is having issues. This is the main hybrid battery yes, not the 12v battery. The dealer agreed to refund me equal to the cost of getting the battery repaired from quotes I had, but I figured I'd be best putting that money to a new battery instead. It wasn't a lexus dealership no. I don't think there is warranty on the car but I'll check that when I get home. I had thought it was only a 10 year warranty on the hybrid battery and that is 12 years old now. The car can cut out at any speed, it seems to only happen when I come off of the accelerator. If I have my foot on the accelerator so the petrol engine is providing power then it doesn't seem to cut out at all suggesting that the petrol engine is fine. It's never cut out when going up-hill for example, its always when I take my foot off the accelerator it seems. Sometimes it will be fine for an hour, other times it will cut out every 5 minutes. I've seen people on this forum saying they had the same issue and replacing the battery solved it completely. If there was a problem with the inverter, wouldn't it show that on the error codes on the OBD reader? I've experimented with it quite a bit including clearing the codes and its always the battery codes that appear on the same modules of the hybrid battery been faulty which would suggest to me its the battery itself as if it was an inverter problem it would be random which cells it was complaining about? Also wouldn't it be showing inverter error codes? The codes I'm seeing are battery module failures (5 of), Replace Hybrid battery Pack and Hybrid Battery pack deterioration. I'll check when the other bits were done on the service history. If its was a transmission failure however, wouldn't this produce an error code? I would be expecting if it was anything other than the battery which is already showing error codes then I would be expecting to see some sort of error on the OBD reader? The car seems to run perfectly smoothly until this occurs, absolutely no issues starting the car or moving off, no knocking or other symptoms which would indicate any transmission problem. Thanks Steven Lockey

Hi all Scenario: I just purchased a GS 450H with a lot of miles on it (177k) and surprise, surprise the hybrid battery was dying. Well, I got some cash back from the dealer and have a new hybrid battery on order to be fitted. The issue is, when I'm driving the car will sometimes cut out, all the electronics e.t.c. are still operating fine, no interruption on music or lights or anything, but the ready light will go out and pressing the accelerator at this point does absolutely nothing. I believe it does beep at me as well. Everything else seems absolutely fine. If I pull over and put it in Park, the engine restarts instantly and without any issues and I can drive off without any problems. It does sometimes seem to 'drag' when I pull off, I can see its trying to recharge the battery at this point on the info screens. Using my OBD reader, the only issues on it are with the hybrid battery. I need to drive my car to get the new battery fitted (or pay for an expensive tow) but its pretty scary when the engine cuts out when you are on the motorway! And I really don't want this to happen when I'm going round the M25! Questions: 1> From what I've read, this problem is basically that the system tries to draw power from the battery, as its on it's way out it doesn't get as much power is it expects and throws a wobbly. Does this seem right? 2> Is there any way to reduce how much power the hybrid motors try to draw to reduce/ eliminate this or even tell the system to just run on the petrol engine? 3> Is there any way to restart the engine without having to stop the car? If I didn't have to come to a full stop when this happened like in a normal (read old 😉 ) type of car then I could at least get there in relative safety. Any other advice would be greatly appreciated. Thanks Steven Lockey