Yaris Cross Hybrid System

[Little Ern]

Hi all, took delivery of a Premiere Edition Yaris Cross at the start of July and what a great motor it is.

I do however have one concern regarding the hybrid system.

Through July it ran fine and then in August I noticed the hybrid system wasn’t coming in as it had previously. My journey to work is only 4 miles, but usually going down hill the hybrid system would come in.

Bristol Toyota South have carried out a thorough hybrid check, pulled the filter out and done what they could based on the information I gave them, but they could find nothing wrong.

For a couple of days after it was checked it ran fine again (or as I expected), however in the last week my fuel consumption has dropped from over 66mpg to 60mpg doing the same journey to work and back and the hybrid system isn’t coming in as much.

is this down to short journeys, or a change in outside temperature maybe? Should I be concerned?

I would just add I have previously had 2 Toyota Auris’ hybrid from new and never experienced this.

Apologies for the long post and thanks in advance for your replies

[TonyHSD]

Hi, 

the fuel consumption change is definitely as a result of temperature drop in the recent days, more members has started to report that and it’s normal, happens every year.
For “hybrid system to come in” - do you mean the car to drive on electric only? If yes then it’s also normal.  
When is cold outside the engine will run longer to warm up itself and to provide heat to the cabin including the hybrid Battery. If there are no fault codes and warnings on dashboard then there is most likely no issues with the car and the hybrid system. The hybrid system you drive now is generation 4 and it’s slightly different from auris which uses generation 3 and so there might be some little differences between and some a bit odd on first sight behaviour from the Yaris. Nothing to worry about. 👍

[Roy124]

As Tony said, many reports.  I posted my YC change in the Corolla mpg thread. 

I don't have my Corolla annual data any more but it typically dropped about 6 mpg month on month at 12,000 miles a year. 

My Cross has dropped 2 mpg in the last week. 

The Car Nut, a US YouTube, related how the Corolla system didn't just circulate coolant around the engine but would close valves to maximise temperature increase where it was needed before opening the valves when up at temperature. 

[Little Ern]

Thank you Tony.

yes I meant for the car to put itself into electric mode.

[Bernard Foy]

Congratulations on your new Yaris Cross, the weather temperatures will affect your new cars MPG. The car is an electronic marvel, it will let you know if it has a problem. Enjoy there’s lots to learn about the Toyota Hybrid and the guys on here are fantastic.

[TonyHSD]

8 minutes ago, Little Ern said:

Thank you Tony.

yes I meant for the car to put itself into electric mode.

You are welcome. 👍
 

[Roy124]

Ern, provided you have enough hybrid Battery power and you are not demanding more power than the car needs you can press the EV button and select EV mode. 

The car will either comply or tell you why it can't.  There has been previous discussion about using the Battery 'on the last mile'.  This will naturally reduce the hybrid Battery power to minimum. 

I can't remember the pros and cons but really it is easier to let the computers do their thing. 

[Little Ern]

12 minutes ago, Roy124 said:

Ern, provided you have enough hybrid battery power and you are not demanding more power than the car needs you can press the EV button and select EV mode. 

The car will either comply or tell you why it can't.  There has been previous discussion about using the battery 'on the last mile'.  This will naturally reduce the hybrid battery power to minimum. 

I can't remember the pros and cons but really it is easier to let the computers do their thing. 

I have been trying this out Roy, I can only ever get it to come in at 24mph or less, is this correct?

With the responses I’ve had I’m happy to let the car do it’s thing.

[IT Troll]

I find that the engine fires up more frequently in you have climate control turned on.

[Hybrid21]

7 hours ago, Little Ern said:

I have been trying this out Roy, I can only ever get it to come in at 24mph or less, is this correct?

With the responses I’ve had I’m happy to let the car do it’s thing.

Yes Jonathan, your speed is limited in EV mode.

 

[Derek.w]

I can do upto 60 mph in electric mode but not for long but this is also on a slight downward slop.

 

[Saxmaniac]

It's best to let the computer look after the hybrid system. If you attempt to get it to run on EV often as possible, let's say you run the Battery down, the engine will kick in to charge the Battery with efficiency losses both ways. Plus you will drive yourself mad trying to second guess the system. Much better to relax and let the car do the thinking,. One thing you can do in the cold weather is not to turn the heater on for the first couple of miles. If you turn it on from cold, the engine will run purely to provide cabin heat 

[TonyHSD]

I believe the hvac system in Toyota hybrids should be set at room temperature (20-22C°) and left permanently on with or without AC but fan needs to work all the time to provide heat in winter and cool air with AC ON in summer to keep thermo management of the hybrid Battery, not too cold and not too hot.
Hybrid Battery likes to be within certain Battery state of charge (40-80%) plus certain temperature (15-30C°). Anything outside these figures and the engine will kick in more often to unload the battery use and obviously this will affect efficiency. 
Another reason to keep interior clean and well ventilated is because this thermo management of the battery happens with the air from the interior, any dirt, moisture, cold or heat actually goes through the hybrid battery cooling system and vents out through vents hidden behind the rear bumper. 👍

[Little Ern]

1 hour ago, TonyHSD said:

I believe the hvac system in Toyota hybrids should be set at room temperature (20-22C°) and left permanently on with or without AC but fan needs to work all the time to provide heat in winter and cool air with AC ON in summer to keep thermo management of the hybrid battery, not too cold and not too hot.
Hybrid battery likes to be within certain battery state of charge (40-80%) plus certain temperature (15-30C°). Anything outside these figures and the engine will kick in more often to unload the battery use and obviously this will affect efficiency. 
Another reason to keep interior clean and well ventilated is because this thermo management of the battery happens with the air from the interior, any dirt, moisture, cold or heat actually goes through the hybrid battery cooling system and vents out through vents hidden behind the rear bumper. 👍

Thank you for this Tony.

Just to be clear, the hvac unit is the heating?

and having the fan on at 20c without a/c on won’t stop the hybrid system from kicking in?

Regarding moisture/damp in the cabin, is it better to have air recirculating in this case rather than drawn in from outside?

[TonyHSD]

15 minutes ago, Little Ern said:

Thank you for this Tony.

Just to be clear, the hvac unit is the heating?

and having the fan on at 20c without a/c on won’t stop the hybrid system from kicking in?

Regarding moisture/damp in the cabin, is it better to have air recirculating in this case rather than drawn in from outside?

Hi,

yes the hvac is the heating, ventilation and air conditioning.
If you use ac the system automatically select air from outside or from inside (recirculating ), you can also notice the system switches between two modes in and out and this depending on outside temperature, inside preset temperature, sunlight, too. You can also override manual on or off ac or manually select air intake from outside or recirculating.

I personally prefer to set the system manually at 22 C° air intake from outside and AC off, air flow towards windscreen and feet. This is during winter season October to April. 
May to September I keep same temperature settings 22C° intake from outside, air flow towards middle of the dash and feet. I turn AC on or off manually and the system switches between air intake from outside or recirculating by itself. I also always keep fan at speed 2. No auto mode. 

These settings works for me the best but may not be suitable for everyone. Best to experiment and see what works best for you.
AC ON help dehumidify the cabin and reduces moisture, suitable for short town drives. I drive a lot , and during winter almost never use ac but the car has plenty of time to reach working temp and to dry and maintain warm interior just with heating ON. 👌

[Cyker]

Yeah, it's one of the few things the hybrids do worse than petrol cars - Because the engine is tiny and not running all the time, it can't store heat very well, and in winter if you have the heating on, it sucks all the heat out of the engine to warm the cabin, which forces the ECU to fire the engine up to generate more heat which wastes more fuel.

This is just one of the downsides of very efficient cars, as they don't have the 'free' waste heat that inefficient cars have.

Even my old Mk1 diesel had this issue - If I wasn't hooning it, I ould get half-way to work before the cold-engine light went out in winter!

It kinda sucks as you have to choose between heating and fuel efficiency. With the HVAC at 20C, it will run the engine a lot more in winter than with it off during urban driving (On fast A-road and motorway the difference is negligible tho'!). As my Mk4 is normally in the mid-70's/low-80's for mpg I couldn't stomach it dropping into the 60s, so turned off the heating and wore a thicker coat!  

It's a real shame they didn't plumb the AC system to be reversible like they have in some of their other cars, so it could act as a heat pump in winter...

[anchorman]

The “automatic climate control” is an expensive item to include in the spec, it seems such a shame to disable it.  The weak link is human intervention that thinks it knows better but it cannot be beaten in most cases (you might need to make small adjustments of temperature in certain light situations due to the sunlight sensor being fooled.  If you set it at say 21 or 22 which is comfortable for most people, on a cold morning you’ll think nothing is happening and there’s when the interfering fingers usually intervene but the moment you touch anything and that auto light goes off, you might as well have a Morris Marina heater.  Left alone, it knows that the only effect of pumping air into the car is to actually lower the temperature so it will hold off until it’s got some engine heat and then you’ll notice the fan speed increasing.  You can’t beat it, it will heat the car up to the selected temperature in the fastest possible time.   Once up to temperature it will start to back off just maintaining your set temperature.   If somebody opens a door it will crank up again.  It also has a 1kw electric heater in the air intake that it can call on to speed things up in really cold weather.  In a hypothetical situation where it is cold overnight and warm in the afternoon, it will heat up then cool down.  It controls air distribution so on a frosty morning it knows the air inside is warmer than the air out so it sets recirculation but soon backs it off and puts a bias to the windows to defrost them.  It does the same on scorching hot days.  When the car is switched off it opens the internal vents to help reduce condensation.  The new 23 models will have nanoe control which senses seat occupancy to maintain efficiency and again includes individual side to side airflow in addition to dual controls. It also eliminates that damp smell you can get with aircon.   It all only works in the auto position.  Selecting eco  backs off the compressor, makes adjustments to fan speed and recirc modes so economies don’t need to be done manually.  Personally, if I’ve paid for that lot I’m using it.  
 

https://www.lexus.eu/discover-lexus/loft-by-lexus/nanoe/?lexReferrer=https%3A%2F%2Fwww.google.co.uk%2F#hero

[MikeSh]

13 minutes ago, anchorman said:

The “automatic climate control” is an expensive item to include in the spec

I spent a big part of my working life in HVAC control systems. It is actually impossible to persuade most people that 'automatic' means it doesn't need you to micro-manage it. Tell it what you want and go away! 🙂

Same with automatic gearboxes where manufacturers have to provide manual shift paddles, or the like, to keep people happy for the first few days/weeks of ownership by letting them be 'in control'. Most never get used again after that because ... not Lewis Hamilton.

[anchorman]

11 hours ago, MikeSh said:

I spent a big part of my working life in HVAC control systems. It is actually impossible to persuade most people that 'automatic' means it doesn't need you to micro-manage it. Tell it what you want and go away! 🙂

Same with automatic gearboxes where manufacturers have to provide manual shift paddles, or the like, to keep people happy for the first few days/weeks of ownership by letting them be 'in control'. Most never get used again after that because ... not Lewis Hamilton.

Like I said, it might need slight adjustments to the temperature and if someone gets in dripping wet through it might need demist but the windows will never steam up and it will stabilise the selected temp quicker than any fiddling can do.  Another thing I forgot to mention is that once it has stabilised the temperature, after a period of time it will deliver cooler air to the face via the fresh air vents.  This is outside temperature linked so in winter it will take the chill off it.   The later ones with nanoe ones when they come help to add moisture to skin. To hear people talk, you’d think these systems were chucked together with no thought but it’s quite a clever bit of kit that accounts for a large proportion of the cost of the car.  I’d urge people to trust it.  

[RickyC]

On 10/2/2022 at 11:12 AM, Little Ern said:

Thank you Tony.

yes I meant for the car to put itself into electric mode.

You had this behvior with cloudy or raining wheater with a growth of air humidity ?

It's a well known behaviour we noted in Italy ( and I was surprised not ti find it reported on other countries ).  ICE stays on longer, SOC grows to 8 tabs and EV don't lights up in display.  

It's caused by GPF cleanup.  When external temperature drops the GPF has problems to warm up execially on short trips so ECU tries to keep ICE on to warm up it and clean the filter. 

A trick we found ( seems back magic 😄 ) is to accelerate ( to 30 or more MPH ) and immediately release at least three times ( obviously do this where not dangerous for other cars ) after coolant indicator as reached at least 3 tabs.  Usually after this cure car behaves correcctly for about 100-150 miles. 

In Italy Toyota made a deep monitoring on some voulenteers' cars ( installing some extra monitoring devices ) but after having got these data there was no more feedback ( and I see the issu is still present on MY22 cars ).