Yaris Hybrid - ICE running most of the time

[Cyker]

The reduced fan speed stops it sucking heat from the engine as quickly (Or cold from the AC!) which means the car doesn't have to expend as much energy running them.

It does make it take longer to cool down/warm up vs normal or fast modes tho'. I tend to leave it in eco, except in summer when the car is an oven, then fast comes into its own! Tried fast in winter but it just made the engine run pretty much all the time as the higher fan speed was sucking heat out of the engine so quickly! (And it still didn't really warm the car up...)

In winter I tend to leave the HVAC off until the engine has reached 4 bars of heat, then at least some meaningful warmth will get blown through the vents than just lukewarm air.

 

[CPN]

21 hours ago, Cyker said:

That said, I think there may be more than one thing in effect here - I have noticed sometimes the engine will still run at maybe 800-1000rpm for no apparent reason, usually after I've been hooning it about;

That's what happens when it does its "Idle Check" which comes up clearly in Hybrid Assistant (the words come over the top of where "S1" to "S4" comes up here...)

21 hours ago, Cyker said:

It's been suggested this may be the engine regenerating the particulate filter. However, this isn't season dependent as it happens summer or winter, so maybe the cold weather is a red herring in this case if that's all it is.

There are two distinct behaviours I've noticed - If it's 800-1000rpm it's this suspected-GPF-regen behaviour, but if it's over 1000rpm it's more likely heating.

No, it's just "Idle Check" whatever that means lol! (perhaps it's just the system checking that the ICE will idle correctly without stalling when it is off load?)

 

[CPN]

2 hours ago, Trewithy said:

I put the CC into Eco mode today and the first thing I noticed was the reduced fan speed.  Then I was aware that the ICE was cutting out more frequently and the car was going further in EV mode.  Bound to be more economical so I will leave CC in Auto with Eco mode turned on.  

That's how I leave mine 100% of the time year round...

[SouperChris]

What MPG you getting?

[MikeSh]

3 hours ago, SouperChris said:

What MPG you getting?

See the 6th post on page one.

[SouperChris]

On 10/9/2022 at 7:26 AM, Yaris2022 said:

No, I always make sure I drive in D, and normally, I have the climate control off in the car. I have tried both off and on, and it doesn't appear to make any difference, strange. I like to think I drive it to the best economy, so I can't think of anything that I've changed to cause this? Have you ever experienced anything of this nature?

 

Yes, I monitor the fuel consumption independently of the dashboard... the indicators seem to give best case scenarios. However, I have noticed, I used to get around 85MPG for my trips according to the dash... but since the ICE has been running more, it has reduced to about 45 - 50MPG. I do have an Android phone, yes.

 

Oh, and sometimes, halfway through a drive, it will go back to normal, with the 'rough' ICE shutdown when pulling off the accelerator, and will continue to do that. But most of the time, it runs the ICE. That I can't understand?

 

Thanks

Your MPG must be per trip I guess? Whats the average? I get a reported average 67, and that seems quite consistent regardless of how or where I drive. 

[Yaris2022]

Hi again all,

 

My average MPG is around 82, as things stand.

 

I may have fixed it... touch wood. I read on a Prius forum or somewhere like that about the 12v Battery being low, and I believe this may have been the problem. I sat with the car in "Ready" mode whilst having lunch at work over the past few days (30 mins each day), and the car has gone back to normal, the engine cuts off after about 1 minute of warm up and then the car goes into EV upon releasing the accelerator, every time. 

Would a low 12v Battery cause this behaviour?

[Cyker]

My tank average is usually around mid-high 70's.

If I've been particular hoony it will be low 70's, and if I'm on an economy run I've been able to get it into the low 80's.

The autumnal temperatures have already triggered a slight drop in the average mpg tho'!

 

[TonyHSD]

3 hours ago, Yaris2022 said:

Hi again all,

 

My average MPG is around 82, as things stand.

 

I may have fixed it... touch wood. I read on a Prius forum or somewhere like that about the 12v battery being low, and I believe this may have been the problem. I sat with the car in "Ready" mode whilst having lunch at work over the past few days (30 mins each day), and the car has gone back to normal, the engine cuts off after about 1 minute of warm up and then the car goes into EV upon releasing the accelerator, every time. 

Would a low 12v battery cause this behaviour?

Not 100% sure if a low 12v Battery can cause this behaviour. Usually the 12v Battery gets power from the hybrid Battery which gets power from the ice, therefore it is possible indeed, especially if you drive on short journeys. I keep my car ON for long hours and I do drive a bit more than average and never experienced anything similar, but my car is also different though. The ice only comes on and stays on more often in  certain conditions only like when driving in hot weather with ac on, after a long downhill, when outside is cold, etc 

[Cyker]

I think the short answer is the car just does weird stuff sometimes, but it's best to just let it do its thing and concentrate more on the driving!

It's hard for me sometimes because I get a bit OCD when it suddenly displays a new set of behaviours I haven't seen before and I'm wondering why it's doing that or if something's wrong, but then it goes back to normal, so I just add it to the list of weird stuff the car does that's apparently normal  

[Yaris2022]

Spoke too soon.... The issue came back this afternoon after being fine this morning.

I was highly suspicious that it is to do with the 12v Battery, so I checked in the service menu on the head unit.

The voltage in ACC / ON was only 11.6v - I think it should be 12v or higher, right?

When I started and put the car into Ready mode, the Battery voltage rose to 13.7v, which shows that the 12v Battery is being charged by the traction battery.

[Graham47]

Isn’t that how it’s meant to work ?
The 12v Battery is charged by the hybrid Battery via a DC-DC converter when in Ready mode.

[Yaris2022]

Yes, sorry, wasn't clear, I was just saying that the fault is not with the DC-DC converter or anything like that, as it is actually charging the Battery, and the 13.7v proves this.

The Battery voltage just seems low when not in Ready mode, I was expecting somewhere in the region of 12.5v or somewhere like that.

[TonyHSD]

4 minutes ago, Yaris2022 said:

Yes, sorry, wasn't clear, I was just saying that the fault is not with the DC-DC converter or anything like that, as it is actually charging the battery, and the 13.7v proves this.

The battery voltage just seems low when not in Ready mode, I was expecting somewhere in the region of 12.5v or somewhere like that.

Yes, 

your 12v Battery seems on the lower side. It might be going flat soon. What do you think of getting a trickle charger and connect it to the Battery for overnight and leave it until the charge fully conditioning the Battery and then measure the voltage again. Also measure while the brake booster is working , while stepping on the brake and hitting the start button. I don’t know if low 12v battery can affect Ice and make it work more., perhaps unless your hybrid battery is low too and the engine needs to recharge it. 
You can also disconnect the 12v battery negative terminal for 30 min and reconnect. This sometimes fix minor bugs. 
Good luck 

[Cyker]

That is a bit weird, it should be at least 12v unless something is drawing so much power it's being pulled down to 11.6v...!

[CPN]

When I haven't driven our car for a few days, I regularly see (before start up) voltages as low as 11.6v on my hybrid assistant app... If I drive the car more regularly during a week, the reading is closer to or over 12v most of the time...

[Gerg]

3 minutes ago, CPN said:

When I haven't driven our car for a few days, I regularly see (before start up) voltages as low as 11.6v on my hybrid assistant app... If I drive the car more regularly during a week, the reading is closer to or over 12v most of the time...

I used to keep an eye on these things when our Auris was much newer, at about 3 years old.  The above was much as I noted.  It did concern me at first - the car had been registered to Toyota for the first couple of years of it's life and had only done about 2000 miles in that time;  I thought they'd killed the Battery with lack of use.

But, 6 years later on, the 12v battery's stilll hanging in there (just?)!

I did wonder if Toyota had chosen an AGM Battery as it was more suited to being left repeatedly, partially-discharged, without suffering damage.  But the newer models don't seem to follow this Battery choice for some years now, so bang goes that theory...

[Cyker]

Strictly speaking, it's deep-cycle batteries (Which may or may not be AGM!) which are the ones that are more resistant to being discharged.

An AGM starter Battery will still have the same degradation issues from being discharged as gel and flooded batteries, just not as bad as wet batteries due to the whole thing being clamped very tightly together.

We use deep-cycle AGMs in our server Battery backup systems and they last ages; Once we were given AGM starter batteries by mistake and IIRC they didn't even last a year before failing! (Starter batteries really like being kept at 100% charge all the time or they degrade faster, and being cycled repeatedly is really bad for them!)

[baxuz]

Somewhat related — is there a point to having the AC on when heating if there is no inverter functionality?

[TonyHSD]

4 hours ago, baxuz said:

Somewhat related — is there a point to having the AC on when heating if there is no inverter functionality?

There is point if you prefer drier air and faster windscreen cleaning function than if you only use heating. I personally prefer not to use any AC during winter. I drive a bit more and my car has plenty of time to dry and condition it’s cabin only with heater. 

[Max_Headroom]

9 minutes ago, TonyHSD said:

I personally prefer not to use any AC during winter.

Does not running it cause any problems, surely using it just  to fast demist the screen in winter helps keep the system working properly.

[TonyHSD]

2 minutes ago, Max_Headroom said:

Does not running it cause any problems, surely using it just  to fast demist the screen in winter helps keep the system working properly.

No problems if you don’t use ac at all. I have done this on many different cars without any complications. Sometimes I don’t switch it on for over 4 months, probably 5-6 and my ac is still working great after many years and miles. Some people simply does not like air conditioning either at home, car, office or on the plane. Some places we don’t really have a choice, but is others we do and so no trouble if we don’t use it. 👍

[Max_Headroom]

5 minutes ago, TonyHSD said:

Some people simply does not like air conditioning either at home, car, office or on the plane

I am the opposite my last car didn't have it (not my choice) and last summer was a nightmare i was so glad to finally see the back of that car and get into the Yaris. 

[Cyker]

It probably depends on how well the system is made, but generally, using it more regularly is better for the system than not using it.

I'm pretty sure the reason the one in my Mk2 failed so catastrophically is because the previous owner never used it, so oil and gas was never circulated round the system and the gas slowly leaked out, eventually allowing atmospheric air into the system, which is really bad as any moisture getting into the refrigerant lines will turn into an acid.

I'm in my car a lot and just can't deal with no AC, esp. in summer! I had enough of that in my first car and after suffering with that every summer I vowed to never get another car without AC!!

[TonyHSD]

Definitely AC it’s a must have extra for any car these days and particularly for hybrids as the cool air from the cabin cools off the hybrid Battery.
The thing is that in cold days (nights) even if the ac is ON it may not work most of the time because air conditioning in cars does not start when outside temperatures are below 4C°. When engine is running and create some warm air around the car outside temperature sensor picks this temperature rise and the ecu turns on the air conditioning, often just before your end of the trip and the ac evaporator becomes cold while the heating core is hot, they are located in close proximity and the results of having two radiators one extra cold and one extra hot next to each other is condensation and moisture. This is one of the reasons why we do get smelly hvac systems in cars. The other reason is not using the fan at all. This is the worst case because when not using the fan there is almost no air going through the air ducts and vents and these start to build bacteria that causes the bad smell.