Weird behaviour

[Simone80]

hi guys

this morning the car had something strange going on (MY22 2.0)

cruising lets say 70-80km/h (50mph?) and releasing ALL the throttle, almost always the engine didn't turn off, and when it did, some meter after (always no throttle engaged) it turned itself on

Battery was over 50%

anyone had this behaviour before? it lasted like this all the trip this morning (22km)

[philip42h]

When you say 'cruise', I assume from what you say that you are driving at a more or less constant speed under the control of your right foot rather than making use of the Cruise Control system in any form?

When using Cruise Control, in a RAV admittedly, the system nearly never stops the engine - the electric motors harvest engine on the downhill stretches to deploy on the next incline. And that is more efficient than stopping and restarting the engine.

Under driver control, if I lift my foot off completely, the engine will normally stop and the car will gently slow as the electric motors start to recover energy.

But not always or under all circumstances - at times the system just decides that the engine should run and at times the engine will start for no obvious reason ...

Either way, I wouldn't worry about it! 😉

[Big_D]

This is perfectly normal. Happens in my C-HR too.

[Cyker]

They do seem to do weird things like that sometimes; I find it's best to not worry about it and let it do its thing.

The most likely reason is it's regenerating the particulate filter, and trying to stop it just makes it start again, prolonging it. I find I have to just let it get it do its thing, then it goes back to normal behaviour.

Another reason it'll run the engine unexpectedly is when it's trying to generate heat to warm the cabin - I often turn the HVAC off in the morning as the engine will waste a lot of fuel running just to warm up in slow traffic, which it would do anyway once I get to the A-road, so I leave it off until it hits operating temperature naturally.

(This does mean I'm freezing my proverbials off in winter, but I just can't deal with the 20+mpg drop I get if I let it do what it wants to do!)

[TonyHSD]

7 minutes ago, Cyker said:

They do seem to do weird things like that sometimes; I find it's best to not worry about it and let it do its thing.

The most likely reason is it's regenerating the particulate filter, and trying to stop it just makes it start again, prolonging it. I find I have to just let it get it do its thing, then it goes back to normal behaviour.

Another reason it'll run the engine unexpectedly is when it's trying to generate heat to warm the cabin - I often turn the HVAC off in the morning as the engine will waste a lot of fuel running just to warm up in slow traffic, which it would do anyway once I get to the A-road, so I leave it off until it hits operating temperature naturally.

(This does mean I'm freezing my proverbials off in winter, but I just can't deal with the 20+mpg drop I get if I let it do what it wants to do!)

I think differently here. I might be writing and happy to be corrected. 
I do prefer my engine to warm up a bit even before the initial drive off as I don’t like driving it with cold engine. I even wait at least a minute and then drive off. Meanwhile the engine is running to warm up itself also is recharging the Battery which will help soon after. Also when Battery been charged gets warm up too plus the cabin heat will warm up the Battery as well. 
Traction batteries as far as I know like to be around ambient temperature, evs has precondition, Toyota hybrids doesn’t which means when battery is very cold or very hot the car ecu will fire up the engine to propel the car although we have a good battery charge available but we aren’t at the right temperature and this can add extra stress to the battery. The car software knows that and acts so engine will work and burn fuel to protect its battery. 
Heat ( temperature) management is the key for battery life and performance. 
This is also a reason I believe why sometimes in certain condition some Toyota hev or phev are running their engines although without obvious reason or with warning messages like “ to protect the hybrid system “. 👍

[Cyker]

Oh I don't mean I'm trying to prevent the engine running at all - It'll still go through that normal start up sequence thing it does; Just that having the HVAC off means it'll stop when it finishes, whereas with the HVAC on it'll be running the entire time I'm in traffic rather than cycling between ICE and EV.

I am slightly wondering if mine has a problem, as quite a few of you have said your hybrids heat up quite quickly, but mine very does not - If anything it behaves a lot like my old diesel, in that if the engine is running with no load it basically doesn't generate any heat and takes forever to even get off 1 block of heat on the temp gauge! It does heat up much faster as soon as I'm accelerating and actually moving rather than just creeping slowly through traffic jams 'tho.

 

[TonyHSD]

2 hours ago, Cyker said:

Oh I don't mean I'm trying to prevent the engine running at all - It'll still go through that normal start up sequence thing it does; Just that having the HVAC off means it'll stop when it finishes, whereas with the HVAC on it'll be running the entire time I'm in traffic rather than cycling between ICE and EV.

I am slightly wondering if mine has a problem, as quite a few of you have said your hybrids heat up quite quickly, but mine very does not - If anything it behaves a lot like my old diesel, in that if the engine is running with no load it basically doesn't generate any heat and takes forever to even get off 1 block of heat on the temp gauge! It does heat up much faster as soon as I'm accelerating and actually moving rather than just creeping slowly through traffic jams 'tho.

 

I don’t think you have a problem with the car, it’s just because of the hvac settings. If I switch off mine acts exactly the same. 
 

[GBgraham]

13 hours ago, TonyHSD said:

I think differently here. I might be writing and happy to be corrected. 
I do prefer my engine to warm up a bit even before the initial drive off as I don’t like driving it with cold engine. I even wait at least a minute and then drive off. Meanwhile the engine is running to warm up itself also is recharging the battery which will help soon after. Also when battery been charged gets warm up too plus the cabin heat will warm up the battery as well. 
Traction batteries as far as I know like to be around ambient temperature, evs has precondition, Toyota hybrids doesn’t which means when battery is very cold or very hot the car ecu will fire up the engine to propel the car although we have a good battery charge available but we aren’t at the right temperature and this can add extra stress to the battery. The car software knows that and acts so engine will work and burn fuel to protect its battery. 
Heat ( temperature) management is the key for battery life and performance. 
This is also a reason I believe why sometimes in certain condition some Toyota hev or phev are running their engines although without obvious reason or with warning messages like “ to protect the hybrid system “. 👍

I am with you on this Tony HSD. I leave my property and it's all down hill for well over half a kilometre but if my engine is cold I always blip the throttle to make it start, the engine only runs for a minute or so and stops but I do have a warm engine with it's oil circulated for when I need to rev up and go. This maybe is an age thing and being old school but I always think of the mechanicals of all my vehicles and BTW I never use B on the shift for the same reason!

I never worry about the rest of what's switched on or isn't, if the engine cut's in or not as I generally get an average of  between 4.3/4.5ltrs per 100km, around 65 imp gallon in your money which is fine for me.

 

[Big_D]

I too make sure my engine is warmed up before I start on a journey. 

[Gray86]

On 5/4/2023 at 6:14 PM, TonyHSD said:

I think differently here. I might be writing and happy to be corrected. 
I do prefer my engine to warm up a bit even before the initial drive off as I don’t like driving it with cold engine. I even wait at least a minute and then drive off. Meanwhile the engine is running to warm up itself also is recharging the battery which will help soon after. Also when battery been charged gets warm up too plus the cabin heat will warm up the battery as well. 
Traction batteries as far as I know like to be around ambient temperature, evs has precondition, Toyota hybrids doesn’t which means when battery is very cold or very hot the car ecu will fire up the engine to propel the car although we have a good battery charge available but we aren’t at the right temperature and this can add extra stress to the battery. The car software knows that and acts so engine will work and burn fuel to protect its battery. 
Heat ( temperature) management is the key for battery life and performance. 
This is also a reason I believe why sometimes in certain condition some Toyota hev or phev are running their engines although without obvious reason or with warning messages like “ to protect the hybrid system “. 👍

The Corolla does some kinda engine protection regime when you start it (cold or warm) where the engine idles for first few minutes of driving (idle as in low Revs with MG1 generating) whilst MG2 drives the wheels. Once suitable heat in the engine it will then provide power to the wheels, and works overtime to recharge the hybrid Battery. Not sure if the 1.8 does this, but the 2.0 does every time. 

[Cyker]

Mine also does it; I think all the Toyota hybrids do something similar

[Chrisg99]

If you start your car then put seat belt on, have a fiddle withthe controls even though they are exactly as they were when you last parked it up the engine has had around a couple of minutes and away you go.

[Roy124]

50 minutes ago, Chrisg99 said:

If you start your car then put seat belt on, have a fiddle withthe controls even though they are exactly as they were when you last parked it up the engine has had around a couple of minutes and away you go.

Why? 

Once it fires up it will warm up more quickly under moderate power.  It will shut down when it's ready. 

Mine will start to move from the garage under Battery, the engine may start briefly, if the aircon is off, and then shut down until more power is required. 

[TonyHSD]

13 hours ago, Gray86 said:

The Corolla does some kinda engine protection regime when you start it (cold or warm) where the engine idles for first few minutes of driving (idle as in low Revs with MG1 generating) whilst MG2 drives the wheels. Once suitable heat in the engine it will then provide power to the wheels, and works overtime to recharge the hybrid battery. Not sure if the 1.8 does this, but the 2.0 does every time. 

They all do. Mine does it every time and it feels like ev with range extender. 👍

[Penfold72]

I've seen this with my 22 plate 1.8 

When on motorway, and I release throttle, display shows the green arrow to indicate charging Battery, but no ev light indicating engine has stopped, sometimes if I gently push throttle arrow changes to yellow showing Battery powering wheel but still no ev light. It's like batterys powering car, but engine still running, but nothing on hybrid display indicating engine is doing anything . I thought it was odd, but as I'm very new to hybrid thought it was what they did. I assume engine powering something. Sometimes after a few seconds the ev light comes on.

[Chrisg99]

23 hours ago, Roy124 said:

Why? 

Once it fires up it will warm up more quickly under moderate power.  It will shut down when it's ready. 

Mine will start to move from the garage under battery, the engine may start briefly, if the aircon is off, and then shut down until more power is required. 

Just time to get the oil circulating before moving off.

 

[Big_D]

I too like to get the oil circulating before I need to use the ICE at higher revs.

[Simone80]

thank you for the replies

fact is that the car never did this before in a year since I bought it in the exact same road and conditions, now it started to do it, and when it starts it last like this like until I park and shut down to the next day:

so i'm in ligh downhill (no cruise control) 100km/h, 4/8 Battery SOC, no throttle, the engine shut down correctly, and the car slows gently, then after lets say 10 seconds reached 70km/h the engine turn itself on and I obviously have no more Battery regen and lets say only 5/8 Battery SOC.. before this "issue" the engine never turned on unless I press the throttle pedal and the end of the downhill is reached

note that when this happens, the next time I release the throttle before a roundabout, the engine won't turn off, or if it turns off, it turn on after few seconds always without touching the throttle

I know that for some reason the car sometime has to regenerate the particulate filter, so i'm not worried if the engine does not turn off always when I release the throttle, but this thing is happening since 2 weeks now, nearly every day when I do this downhill

 

in my opinion it behaves like the battery is too hot to recharge, but it's impossible as it did again yesterday with 12°c plus rain (20°c in the cabin) but battery fan revs low and there's no "hot" air from it, i can't use hybrid assistant as my dongle don't show the battery temperature

[Simone80]

so, went to the dealer and obviously the car in that 10minutes trip with the mechanic ran fine

I told them what it does and they kindly say that without errors in the dash or error in the diagnose system can't open a request to Toyota

so I guess I have to live forever with this """"""malfunction"""""" 😡

[Big_D]

4 hours ago, Simone80 said:

so, went to the dealer and obviously the car in that 10minutes trip with the mechanic ran fine

Typical, isn't it. I had a similar problem with mine. Noisy brakes and rattle in the rear. Went for a drive with the technician, and the car behaved perfectly.

[Cyker]

That is a big problem with a lot of modern mechanics - They are totally reliant on the computer and don't have any of the ability to look beyond it like old school mechanics do.

TBH, unless it's having a noticeable effect, e.g. noticeably lower fuel economy, then I'd just chalk it up to another of the many weird behaviours of the car and ignore it.

Someone mentioned driving around in B-mode for a while helped with theirs so might be worth a shot?

[TonyHSD]

I think nothings wrong with your hybrids. I have one and drive it myself for over 200k miles for 8 years of ownership and the car still surprises me from time to time, it does it’s things differently depending on weather, set ups, temperature and charge of both batteries, fuel types, and list goes on. I had twice or perhaps three times more serious problems and in all those cases there were warnings and messages on dashboard clearly indicating a problem. Just drive your cars, do your use checks and enjoy the cars . If anything goes bad you will be noted. No need to look for some wrong when it might be no problem. Does anyway in the car book states that engine will run longer or unexpectedly to regenerate its gpf filter, I wonder if it’s true or another myth? Toyota hybrids has gpf since Prius from 2010 and I never knew of this regenerative process. 

[Simone80]

Yes but in that case the engine will stay ON until it finished the process, I know that's normal.

In my case the engine correctly turns off, then without touching anything, on itself, not only in downhill but now also approaching a roundabout. Never did in 10 months, same roads (work to home)

As it's governed by a (long) piece of software, the car has to work exactly the same as it worked the first 10 months of ownership: if it doesn't, something has changed, be it a sensor o something else, I don't know. If the car worked like this since day1 I obviously I wouldn't have reported anything to the dealer

Question is: your C-HR when you decelerate with no brakes and no gas, has ever started the engine?

[Cyker]

What temperature do you have your climate control set to out of curiosity? The only time I've been decelerating and had the engine kick in is in winter when it was cold, and I've had the heating turned up.

The only other thing I can think of is if your 12v Battery might be acting up, as that can cause weird things to happen.

 

[TonyHSD]

5 hours ago, Simone80 said:

Yes but in that case the engine will stay ON until it finished the process, I know that's normal.

In my case the engine correctly turns off, then without touching anything, on itself, not only in downhill but now also approaching a roundabout. Never did in 10 months, same roads (work to home)

As it's governed by a (long) piece of software, the car has to work exactly the same as it worked the first 10 months of ownership: if it doesn't, something has changed, be it a sensor o something else, I don't know. If the car worked like this since day1 I obviously I wouldn't have reported anything to the dealer

Question is: your C-HR when you decelerate with no brakes and no gas, has ever started the engine?

Yes, when hybrid Battery gets topped up full or near full the engine kicks in with no obviously reason. This can happen while going downhill, when cruising on flat roads or after some long drives , even the engine can start after you had come to a complete stop or after you move on in ev . Of the car had any trouble you will have fault code. Non fault detected issues with engine are usually related to dirty throttle body or egr but your car is almost  new so I will not suspect these.