Check hybrid warning light

[L3xu5 Mum]

Just driven from uk to Italy and for first time ever a Check Hybrid warning light (in yellow not red) has come on. No apparent issues with the car - any suggestions? 

[Spock66]

First step is you need access to the fault codes, only other thing to check is the 12v Battery, anything else would just be a guess.

[L3xu5 Mum]

2 hours ago, Spock66 said:

First step is you need access to the fault codes, only other thing to check is the 12v battery, anything else would just be a guess.

 

[L3xu5 Mum]

Thanks Spock66! Unfortunately I don’t have that widget thing that provides fault codes with me. Lesson to be learned when planning road trip! Running purely as petrol engine so no hybrid at all. May try disconnecting the 12V to try and reboot? 

[Herbie]

1 hour ago, L3xu5 Mum said:

Running purely as petrol engine so no hybrid at all. May try disconnecting the 12V to try and reboot? 

You may have found out by now that that's impossible to do. If the car is running then the hybrid system is active.

Hybrids don't have a starter motor. The way to get the petrol engine running is that the hybrid system energises the 650V MG1 (Motor/Generator 1) and uses that to spin up the engine, before applying fuel and a spark to fire it.

Disconnecting the 12V Battery for a few minutes is worth a try but as Andrew says above, you need the OBD codes. These codes provide a starting point for further in-depth troubleshooting so if you don't have them, all we can do is guess.

[Dave450h]

This happened a few months ago on my 2010 RX450h.  I disconnected the 12v Battery and  reconnected it again and the error disappeared for a short while. however it came back after a week or two. 

 

I took it into Lexus Cheltenham and they replaced the Hybrid coolant pump. This has fixed the problem but cost me £1000.

 

 

 

 

 

 

 

 

[L3xu5 Mum]

Thanks to Herbie and Dave 450h.  Both very informative and I’ve learned a bit more about my RX450h.  Interestingly the code has now disappeared after having a look at the 12v Battery my husband found a ‘breather’ pipe disconnected.  After reconnecting I started up and the code was gone!  The car drove beautifully back from Tuscany to England. Keeping everything crossed she behaves herself going forward…….

I really did appreciate the replies I received so thank you.

[cruisermark]

Could it be that the the rise in outside temperature has triggered the light/error?

[Greisingel]

Keep those air inlets under back seats clean. They can gather tons of fluff. Easy to clean – unscrew out, vacuum and wash

[L3xu5 Mum]

Thanks Greisingel for the suggestion - it makes sense.  I shall have a look. Thanks again 

[Greisingel]

And an added measure – waterproof the rear seams and trunk joints. I used LS-X a translucent plumbing mastic. And it has worked.

Just make sure your Battery is DRY. I took all the rear trunk flooring out and discovered a small swimming pool that had breached the isolation – causing the batter management unit to throw up in my case a red Hybrid warning. Had been trickling in around the rear light and hinges....check the roof rack rear runners and caps too. I put in a few of those silicate dehumidifier things in the wee storage areas to help keep the moisture down.

They are a great drive. I just came back from 1000 Km French drive – not a missed a beat. 120 kmh for 100s of KMs. Hope I haven't put the mockers on saying that.

Good luck