Check hybrid system/check VSC sensor

[wangnima4236]

Hey guys, it's just as shown in the title, last Thursday I had this issue and all the lights were lit up, including the two for batteries, and I couldn't start my car. I had to erase the code with a reader and drive home. I've been reading posts about this and seems to be a common issue. Please can anyone had similar or same issues talk about the experiences and solutions? Many thanks.

[katabrontes]

I get a similar problem with my RX350 although clearly it doesn't include any Battery problem.  From time to time, either immediately after starting the engine or while driving, the VSC, brake and ABS light either stay on or light up.  Everything works including ABS when I have tested it by sharp braking on grass.  No fault codes have ever been detected either by my little dongle or my garages more sophisticated system on a laptop.  The lights are always cleared by stopping the engine and restarting.  Sometimes it seemed to be related to driving in the rain but not necessarily.

Various explanations have been proposed (dirty ABS sensor discs on the brakes, differing tyre pressures (affect the rolling diameter of the wheel so speed of rotation varies thus simulating a skidding wheel)).  None of these have been validated.

The final conclusion has been that it's caused by some obscure software glitch in the main ECU which resets itself when the engine is switched off and restarted.

This has been happening for many years and the car has never failed an MOT.

it remains a mystery and I have learned to live with it.

[Mike Fox]

Hi, I've had, a similar problem. Driving normally P/S warning lights up and power steering lost immediately followed by loss of power and "check hybrid system " message. Coasted to a stop on hard shoulder. Turned ignition of then on and engine started ok. P/S light out but message still on. Drove a further 500 miles with frequent stops and starts without problem check hybrid message still on. Screen showing Battery, motors engine etc seemed to show everything working OK. 

Following day, no messages set off and after 30 miles same issue. Again switched off and on, message remained but car behaved normally. 

Any ideas?

I see on a US site that it can be communication error between hybrid batteries and car and another quoting cooling fans problem. I am currently in Spain where I keep the car. It does sit for 2-3 months with the 12v Battery disconnected but I've done this for 10 years or so without any problems. 

 

[Spock66]

I'd suggest checking the 12v Battery in the first instance, a poor Battery is known to throw various spurious fault codes.

[katabrontes]

Of course 'the12volt Battery 'couldn't be the cause of the lights coming on with my 30 as it doesn't have an auxiliary Battery.  It's very odd but does seem to matter in my case

[ColinBarber]

28 minutes ago, katabrontes said:

Of course 'the12volt battery 'couldn't be the cause of the lights coming on with my 30 as it doesn't have an auxiliary battery.  It's very odd but does seem to matter in my case

It only has an aux Battery (no traction battery), but we don't call it that on a conventional engine vehicle - it's just the Battery.

Low voltage can cause spurious errors to appear - possibly your 12v Battery is a bit low, the terminals aren't clean and tight or there is a poor earth somewhere. Measuring the voltage at the ECU as the engine is cranked would confirm if you do have an issue of this kind. But equally, it could just be an obscure software glitch.

[katabrontes]

Thanks Colin.  Certainly not 'a bit low' as it's a new one and terminals are clean and well greased. I haven't checked voltage at the ECU but as the warning lights sometimes stay on after starting, but at other times they come on while driving when drain is lowest and alternator running so voltage should be at max.  My independent garage has checked this several times and nothing found.  Never detected any fault codes.  Lexus dealer had no ideas.  It always clears if the engine is stopped and restarted.

[brendangeorge]

Hi Harry
Check for codes - I had this problem on my RX450h and a new hybrid transmission oil pump was needed.  The list price for a new pump is £850 plus fluid and a couple of hours to fit.
I post about this problem a couple of moths ago.

Good luck
Bren

[katabrontes]

Codes have been checked numerous times and none found.

[brendangeorge]

On 10/24/2024 at 5:00 PM, brendangeorge said:

Hi Harry
Check for codes - I had this problem on my RX450h and a new hybrid transmission oil pump was needed.  The list price for a new pump is £850 plus fluid and a couple of hours to fit.
I post about this problem a couple of moths ago.

Good luck
Bren

Sorry my comments about my post do not apply to your problem Harry.