Car not switching to EV despite full charge

[benfromwigan]

For the 1st 8 months of having the car it would behave as I would expect (engine cutting out and going into electric when driving in the "eco" zone) and  coming on if i gave it a bit more revs or it needed a little more charge.

Then  after 8 months it did something different for about 3 days.  The engine would come on as soon as I start the car and only cut out and go into EV when i come to a full stop at a junction or traffic light.  The rest of the time the engine would be running and charging the EV Battery way past where it norrmally stops. (charge the bars would be all the way full).  After the 2 or 3 days of behaving like this it would return to "normal" again. 

It's done this behaviour another 2 times in the last 2 months.    Can someone explain what is going on and if it is normal?...as when it is going on it really kills the mpg which bugs the hell outta me. 

I just wanna stipulate that I dont have the heating or AC on.  The engine didnt even run so much when we had the freezing cold in winter.

[Yugguy1970]

It might need a run to do exhaust filter regen or something like that.

You may actually be best to have heating and ac on so the engine runs a little more, as if it is never getting hot it won't be able to keep things cleared out.

[Parts-King]

You can't really do anything to control when the car runs on EV or not, it is completely controlled by the ECU to get the best performance out of the Battery. When you say it kiils MPG, what are you getting? There are a number of factors that bring the ICE in to charge the Battery, mainly ambient temperatures, in the winter you WILL get lower MPG, it's part of being a Hybrid owner 

[benfromwigan]

What usually happens when i completely lift off the accellerator and the car has 4 bars or Battery charge is that it will switch to EV.  If its a process of filling the Battery all the way up in order to keep the Battery healthy that's fine.  I was just hoping for clarification from someone else who this happens to.  The battery charge usually hovers around 3/4 bars unless I go on the motorway.

 

With regards to the killing of the mpg.  2 idential journeys..one day when car behaving "normally" 64.7 mpg.  Next day when constantly charging battery - 49.1mpg.

[TonyHSD]

Hi, 

as mentioned above the major factors are outside temperatures and cabin heat. 
Other typical reasons are maintenance of the hybrid Battery cells voltages. 
If the hybrid Battery cells one or more has slightly higher resistance or voltage differences ( I don’t know exact values ) the hybrid system will cycle charging and discharging many times until those gets closer numbers.
These events usually happens on longer motorway journeys and if your car does not get often drives for over 20-30 min then it is very likely you experienced exactly this. 
AC and HVAC should  always been set ON, you only switch those off in very special situations like you want just to move the car in a parking spot and keep in ev mode or for maintenance purposes. You need well ventilated cabin with clean and dry air to maintain correct hybrid Battery temperature. 
As long as there are no faults shown on your dashboard, there is nothing to worry about your car. Just drive and enjoy it. 👍
 

[Parts-King]

1 hour ago, benfromwigan said:

What usually happens when i completely lift off the accellerator and the car has 4 bars or battery charge is that it will switch to EV.  If its a process of filling the battery all the way up in order to keep the battery healthy that's fine.  I was just hoping for clarification from someone else who this happens to.  The battery charge usually hovers around 3/4 bars unless I go on the motorway.

 

With regards to the killing of the mpg.  2 idential journeys..one day when car behaving "normally" 64.7 mpg.  Next day when constantly charging battery - 49.1mpg.

Are you resetting the average MPG every day? if so, don't, you will put yourself in an early grave. Average MPG is exactly that, average worked out over previous miles when conditions like average temperature and road conditions can be different. The ECU will do all the work, the Battery will be maintained between 20 to 80% to protect the longevity. I think you are overthinking it too much 

[benfromwigan]

6 minutes ago, TonyHSD said:

Hi, 

as mentioned above the major factors are outside temperatures and cabin heat. 
Other typical reasons are maintenance of the hybrid battery cells voltages. 
If the hybrid battery cells one or more has slightly higher resistance or voltage differences ( I don’t know exact values ) the hybrid system will cycle charging and discharging many times until those gets closer numbers.
These events usually happens on longer motorway journeys and if your car does not get often drives for over 20-30 min then it is very likely you experienced exactly this. 
AC and HVAC should  always been set ON, you only switch those off in very special situations like you want just to move the car in a parking spot and keep in ev mode or for maintenance purposes. You need well ventilated cabin with clean and dry air to maintain correct hybrid battery temperature. 
As long as there are no faults shown on your dashboard, there is nothing to worry about your car. Just drive and enjoy it. 👍
 

AAh that makes sense as it is mainly short journeys.  Both me and my wife live 5 miles from work so it doesn't often get lengthy journeys.   I'll try turning the AC on too.  My car is going into the dealershipin a couple of weeks for a wheel issue so they will run diagnostics on it just to be sure.

[benfromwigan]

4 minutes ago, Parts-King said:

Are you resetting the average MPG every day? if so, don't, you will put yourself in an early grave. Average MPG is exactly that, average worked out over previous miles when conditions like average temperature and road conditions can be different. The ECU will do all the work, the battery will be maintained between 20 to 80% to protect the longevity. I think you are overthinking it too much 

Nah mate i may be a little anal but I aint that bad.  I just looked on the mytoyota app.  It has the past journeys stats on there.  It's my first hybrid car so im still learning about it.

[Cyker]

7 hours ago, benfromwigan said:

For the 1st 8 months of having the car it would behave as I would expect (engine cutting out and going into electric when driving in the "eco" zone) and  coming on if i gave it a bit more revs or it needed a little more charge.

Then  after 8 months it did something different for about 3 days.  The engine would come on as soon as I start the car and only cut out and go into EV when i come to a full stop at a junction or traffic light.  The rest of the time the engine would be running and charging the EV battery way past where it norrmally stops. (charge the bars would be all the way full).  After the 2 or 3 days of behaving like this it would return to "normal" again. 

It's done this behaviour another 2 times in the last 2 months.    Can someone explain what is going on and if it is normal?...as when it is going on it really kills the mpg which bugs the hell outta me. 

I just wanna stipulate that I dont have the heating or AC on.  The engine didnt even run so much when we had the freezing cold in winter.

The usual reason is it's cold and the engine is trying to generate heat; Since you say your heating is off, that probably isn't the cause.

The other possible reason we've found in the Yaris forum is the newer Dynamic Force engines, like our M15A-FXE and the M20A-FXS in the 2.0L Corolla, have a particulate filter for reasons, and like with diesels they require regeneration from time to time - We've theorized that seems to be the other main cause of the engine running for no apparent reason for extended periods.

However, we've found when it happens, you can drive around in B-mode for a little while, which forces fresh oxygenated air through the exhaust when it engine brakes, and that seems to speed up the regeneration so it doesn't do it for ages.

The theory is, with diesel they have plenty of oxygen (Lean running) but not enough heat (Too thermally efficient), so they have to go on long hard drives to get the exhaust hot enough to burn out the soot. With petrol, it's the other way around - Exhaust gets plenty of waste heat to get it hot, but there's no spare oxygen, so using B-mode to add oxygen to the hot exhaust helps it purge the GPF.

I don't think the 1.8L Corolla hybrids get this as AFAIK they don't have a GPF, but the 2.0L ones are Dynamic Force engines as well, and assuming your GR Sport has one, it probably is this GPF regeneration cycle making it run.

[Don Mac]

2 hours ago, Cyker said:

... I don't think the 1.8L Corolla hybrids get this as AFAIK they don't have a GPF, ...

My understanding is that they do have a GPF. My 1.8 behaves in exactly the manner which Ben has described. When it's doing this the display will often show that the engine is spinning at about 1000rpm, but not delivering power to the wheels or hybrid Battery.

From my limited knowledge of these things regeneration of the GPF seems like a good explanation. A non-hybrid petrol engine will get small, but frequent, doses of regeneration every time you lift your foot off the throttle which a hybrid does not. Toyota therefore have to program their hybrid cars to do it deliberately and, presumably, are pretty conservative about how dirty they'll let the filter get before this happens.

[AndrueC]

18 minutes ago, Don Mac said:

My understanding is that they do have a GPF. My 1.8 behaves in exactly the manner which Ben has described. When it's doing this the display will often show that the engine is spinning at about 1000rpm, but not delivering power to the wheels or hybrid battery.

I think they've all done that. Another explanation I've heard for that is that it's to keep the water pump going to extract residual heat from the engine into the cabin. That would make some sense because mine mostly only does it in winter.

There's a journey I frequently make along the M40 and in winter it will often do what you're describing above while on cruise control. But for the past couple of months now that things have warmed up a bit it drops into EV mode instead.

Another odd behaviour I've seen with my 1.8 though is if you've just rolled down a long hill in EV mode no matter how gently you apply the brakes if you intend to stop the RPMs will sometimes kick up to 2,000 before dropping back to 0.

[Cyker]

20 minutes ago, Don Mac said:

My understanding is that they do have a GPF. My 1.8 behaves in exactly the manner which Ben has described. When it's doing this the display will often show that the engine is spinning at about 1000rpm, but not delivering power to the wheels or hybrid battery.

From my limited knowledge of these things regeneration of the GPF seems like a good explanation. A non-hybrid petrol engine will get small, but frequent, doses of regeneration every time you lift your foot off the throttle which a hybrid does not. Toyota therefore have to program their hybrid cars to do it deliberately and, presumably, are pretty conservative about how dirty they'll let the filter get before this happens.

Ahh, thanks, I wasn't sure!

[benfromwigan]

Some interesting reading here. Thankyou for your inputs. My corolla is a 1.8.....i probably should have started that in my first post. 

I decided on my way home from work to take the motorway route. I hadn't seen the post about driving in b mode but due to someone saying previously about the filter regeneration I thought I'd give it a go. 

By the time I left the motorway the car was behaving normally again and my mpg for the trip was 85mpg.

Incidentally my car does what  AndrueC said and the refs shoot up from 0 to around 2000 for a second or 2 when braking from motorway speed. 

[TonyHSD]

Regarding the engine water pump, this is electric and does not need crankshaft to rotate to operate the pump.
The pump works on 12v supply and can provide heat to the cabin or take heat away from the engine regardless of engine been on or off. 
You may see high rpm after long downhill decent or after heavy braking, this is because the engine is discharging the Battery as the hybrid Battery state of charge is at its maximum levels. The discharging process does not burn any fuel as the crankshaft is turned by the MG1 using power from the high voltage Battery to maintain more appropriate levels. 1.8 hybrids from 2021 second half has gpf fitted similar to 2.0 variants. 
The older models including previous gen 3 hybrids also has something like a gpf or second cat. 
 

[Don Mac]

11 hours ago, TonyHSD said:

...
You may see high rpm after long downhill decent or after heavy braking, this is because the engine is discharging the battery as the hybrid battery state of charge is at its maximum levels. The discharging process does not burn any fuel as the crankshaft is turned by the MG1 using power from the high voltage battery to maintain more appropriate levels. 1.8 hybrids from 2021 second half has gpf fitted similar to 2.0 variants. 
The older models including previous gen 3 hybrids also has something like a gpf or second cat. 
 

Isn't it spinning the engine to introduce 'real' engine braking to replace the regenerative variety (which it can't do because the hybrid Battery is full)?

My understanding is that MG1 has to be turned when the car is moving in order to keep the engine rpm at zero. Slowing it down transfers torque from MG2 to the engine, thus braking the car. If the car was discharging the hybrid Battery when we see the engine spin up like this wouldn't the display show the charge level dropping? (I thought that the system just uses the energy that would have gone into the Battery to turn the engine)

 

[2badmice]

On 4/5/2024 at 8:52 AM, benfromwigan said:

For the 1st 8 months of having the car it would behave as I would expect (engine cutting out and going into electric when driving in the "eco" zone) and  coming on if i gave it a bit more revs or it needed a little more charge.

Then  after 8 months it did something different for about 3 days.  The engine would come on as soon as I start the car and only cut out and go into EV when i come to a full stop at a junction or traffic light.  The rest of the time the engine would be running and charging the EV battery way past where it norrmally stops. (charge the bars would be all the way full).  After the 2 or 3 days of behaving like this it would return to "normal" again. 

It's done this behaviour another 2 times in the last 2 months.    Can someone explain what is going on and if it is normal?...as when it is going on it really kills the mpg which bugs the hell outta me. 

I just wanna stipulate that I dont have the heating or AC on.  The engine didnt even run so much when we had the freezing cold in winter.

I think you're worrying about nothing and to trust your car to do the job.

 

Also keep your aircon on permanently.

[Delta01]

“Also keep your aircon on permanently.”

What is the reason for keeping your airco “on” all the time? Iam only turn it on on a warm day isn’t this the correct way?

sorry double post see quote!

[Delta01]

2 hours ago, 2badmice said:

I think you're worrying about nothing and to trust your car to do the job.

 

Also keep your aircon on permanently.

Why would you do that for?

[Cyker]

It depends on the car - If you have normal HVAC, then it's not a good idea to leave it on all the time as it will just waste fuel.

However, almost all modern cars have 'climate control', which is basically automatic HVAC so it's best to leave the AC 'on' all the time; with climate control systems it won't actually be on all the time, as the computers will cycle it on and off as needed so it doesn't waste fuel and also keeps the system healthier (i.e. less of that mouldy swamp smell you get with normal HVAC if you don't use the AC for too long or only use it with recirculated air).

 

I do miss the manual system in my old diesel Yaris as I used to use it to slow the car down more  

 

*HVAC - Heating/Ventilation/Air Conditioning

[Delta01]

Is the Toyota system different from let’s say VAG but also Volvo where the compressor runs all the time?

[AndrueC]

1 hour ago, Delta01 said:

Is the Toyota system different from let’s say VAG but also Volvo where the compressor runs all the time?

I'd hope so. Running the compressor all the time is a horrible design. I can't even see how it's possible. Surely the coils would ice up eventually rendering the system useless until it was switched off and allowed to warm back up?

I'd expect even a simple A/C system to be cycling the compressor on/off unless you switched it to maximum.

[Delta01]

59 minutes ago, AndrueC said:

I'd hope so. Running the compressor all the time is a horrible design. I can't even see how it's possible. Surely the coils would ice up eventually rendering the system useless until it was switched off and allowed to warm back up?

I'd expect even a simple A/C system to be cycling the compressor on/off unless you switched it to maximum.

Yes I didn’t know that it was like this until my airco fluid was short an my compressor got stuck. The airco fluid is also the lubricant for the compressor. This was on a skoda octavia then i learned about the compressor always turns with the belt. 

[AndrueC]

Interestingly my car did the 'turn off the ICE but keep the rpm at 1,000' even though it was 18c outside and the Battery was at about half. I can understand why it might need to dump incoming charge but what is going on when the Battery is both propelling the vehicle and turning the ICE?

In a related note I also discovered that you can't activate Brake Hold in EV mode. I assume that has something to do with maintaining brake pressure. It was as I was moving around a carpark toward the main road and all the car would say then I pressed the button was 'Brake hold unavailable'. It became available as soon as the ICE started.

[Cyker]

A lot of modern AC compressors are variable displacement types, and do indeed spin all the time, but they vary how much compressing they do from none to maximum instead of cycling on/off with the traditional magnetic clutch.

 

[Babar13]

13 hours ago, AndrueC said:

Interestingly my car did the 'turn off the ICE but keep the rpm at 1,000' even though it was 18c outside and the battery was at about half. I can understand why it might need to dump incoming charge but what is going on when the battery is both propelling the vehicle and turning the ICE?

That's the "IDLE CHECK" mode. Duration 30 seconds then will go to S4 mode and switch engine off... Normal behaviour