Car suddenly stopped (cut off) while driving

[Sirajul Choudhury]

My car Lexus RX400H 2006 suddenly engine stopped while driving, happened 3 times - showed dashboard signals- maintenance sign, and Check Hybrid System, Check VSC system and Check AWD system. After 10 minutes I drove again - then stopped after 10 miles showing the same signals. Any suggestions- what could be the faults. Thanks

[NemesisUK]

It's a hybrid so the (petrol) engine will cut in and out as required whilst driving.

How fast were you going when it cut out?

All the warning indicators could be due to a low charge in the 12v auxiliary Battery. When was the car last serviced? Have you had a hybrid health check done recently?

The best course of action would be to get the car on TechStream and have the codes read.

[Sirajul Choudhury]

Thanks for your reply, the car was serviced 3 weeks ago, normal device, hand brake cable &  rear brake pads were replaced. The car is giving trouble just 2 days after the service. Took back to the garage, they were unable to find any fault. But problem is still there. Took to another garage, they said EGR valve needs replacement. I am confused. Don’t know what to do. Thanks

[Illogan]

Sirajul,

If it was my car I wouldn't have any specific repair made until I knew exactly what was wrong.

As Peter suggested (above) you really need to have the fault codes diagnosed accurately either by getting your own Tech-Stream, and reading the codes (you can publish them on here - and others will tell you exactly what the issue is) - or take it to a Lexus Garage (Dealership or specialist Independent) and have them read the codes for you.

I understand that an issue like this is a concern, but the quickest way of resolving this is to have an accurate diagnosis.

[NMJToolbox]

Whilst I can't really help you resolve your problem you certainly are not alone with it.  This happened to me 3 times in my 2009 RX450H SE-I.  It (for me) always happened when I came to a stop, usually at a junction.  I'd restart the car after a few seconds and it would start again but then all of the lights/warnings you mention started coming on one after the other.  I did have a few more warnings than you mention, Pre Crash System fail, Brake System Fail, ABS Fail.

Lexus checked the errors and said the only error that was there was one that said 'Communication with hybrid system lost'.  They reset it and could not get it to happen again so gave me the car back.  It happened a few weeks later, took it back in and this time they said the ABS sensor at the back was faulty and needed replacing.  I asked why all the other warnings came on and they said that if the ABS sensor goes pear-shaped then it has a knock on effect on the other systems. 

I wasn't too convinced but I also had problems with Battery drain, it would be flat in 3 days on the driveway.  Charge it up fully and it would be flat again within 3 days.  Went back to Lexus and they had it 3 days, could not find a fault but the mechanics noticed that whilst my car was on the ramp and they were eating lunch they saw my car turn it's headlights on, on its own then turn them off after a few minutes.  When I got the car back I turned off the auto lights and the Battery stayed charged.

Never got to the bottom of the cutting out/warnings as I stopped trusting the car so PX'd it for a 2017 RX450H which I picked up yesterday.

[NemesisUK]

When saying the engine stopped do you mean the car fell out of the Ready state i.e. the petrol engine stopped and the hybrid system stopped? By restarting the car do you mean you put the car back into the Ready state?

[NMJToolbox]

22 minutes ago, NemesisUK said:

When saying the engine stopped do you mean the car fell out of the Ready state i.e. the petrol engine stopped and the hybrid system stopped? By restarting the car do you mean you put the car back into the Ready state?

For me, the petrol engine would stop, the info display would say 'Check Hybrid System'. I would have to press the Start/Stop button to 'turn off' the car. wait 10-20 seconds then depress the brake and push start.  At this point the car would start and as soon as I set off all the warning lights would come on one after the other.  I'm not sure if this is exactly what is happening to Sirajul though.

[NemesisUK]

8 minutes ago, NMJToolbox said:

I would have to press the Start/Stop button to 'turn off' the car.

Why? Would the car not move under electric power at this point?

[NMJToolbox]

1 minute ago, NemesisUK said:

Why? Would the car not move under electric power at this point?

Nope, depressing the accelerator would not do anything.  I resorted to the old IT analogy 'turn it off then on again' 🙂

[NemesisUK]

1 minute ago, NMJToolbox said:

Nope, depressing the accelerator would not do anything.  I resorted to the old IT analogy 'turn it off then on again' 🙂

Works for sooo many things these days!