mazda 2 hybrid not turning off the ICE

[yavli]

During the first 2 months (1500km) of driving my new mazda 2 hybrid, I was applying succesfully "pulse & glide": after releasing the throttle, the ICE stopped and the car was moving in ev. The last few days this does not happen. The hybrid system holds the ICE on even after releasing the throttle and the Battery keeps charging till 80-90%. The ICE stops then when I reach a stop (at a traffic light or such). Is this a normal behaviour? Has anyone encountered something similar?

[Mojo1010]

Colder, using heater more?

[yavli]

Thanks for your answer mojo.

No, I'm not using heater these days. This behaviour goes on even after the engine has reached the right temperature, even when I'm not driving uphill. Is there a chance that the hybrid system has adapted to my driving behaviour? On every day basis I drive only 4-5km to my work and back at low speeds - of course every few days I drive for longer distances. The thing that I'm more worried about is the constant charging of the hybrid Battery. During the first 1500km the Battery was always around 50% and charged almost fully only on long downhill roads or after driving for long distances at higher speeds.

[RedToyota]

You might want to have a read through this topic. It might give you some ideas/ answers.

 

[TonyHSD]

Normal behaviour caused by short trips only. Try to use the car longer ( longer time ON) ready mode, not even need to drive it , this will allow the car to condition both batteries and engine will get back to normal operation. Heating and ac should be ON all the time and preferably in auto mode. Just set desired temperature. This is needed to maintain hybrid Battery temperature. 

[takis1964]

as long as the hybrid Battery is charged then my mazda works with EV directly

[Cyker]

The 2 most common reasons for the engine staying on unexpectedly in the Mazda Yaris Toyota Hybrid 2 Mk4 are a) Cold weather and b) What I think is particulate filter regen.

a) Can be mitigated by turning the HVAC completely off, so it doesn't suck heat out of the engine, and the engine temp stays around 3-4 bars

b) Can be mitigated by, when the engine is running unexpectedly, put the car in B-mode and drive in that mode for a few minutes before switching back to D-mode. (Just be prepared as the engine-braking in B-mode is a *lot* stronger when lifting off the accelerator!)

 

a) tends to show itself when the weather starts getting cold, b) tends to show itself when the car is mostly driven at low speeds and stop-start traffic; Mine does it if it doesn't see a motorway or A-road for a while.

[yavli]

Thank you all for the responses. I should also mention that the last few weeks I have been driving constantly in power mode. At first the engine turned off when releasing the throttle, as usual. Do you think that now the car has been "educated" and keeps the engine on for that reason? Or does the driving mode have nothing to do with this behaviour? I will certainly try to make some considerably longer distances at higher speeds, as some of you suggested. 

Are my worries about the constant charging of the Battery (due to engine being on) justified? Or the hybrid system *just knows* what to do best for the hybrid Battery health?

[Cyker]

I find the drive mode doesn't affect that much - Even in Power mode, if you lift off the engine usually cuts out. It's just in power mode, when you touch the accelerator again, the engine will tend to immediately restart whereas in normal/eco it's easier to feather it to keep going on the electric only.

You don't need to worry about the Battery management - It'll take care of itself. The HSD in there is the result of 2 decades of development and all the obvious issues have been ironed out by now.

I suspect doing the B-mode trick will fix it, but it's still good to give the car a good run now and then.

[MikeSh]

21 minutes ago, Cyker said:

The HSD in there is the result of 2 decades of development

The concept car was shown in 1995 with Prius on sale from late 1997, so it must be at least 3 decades.

[TonyHSD]

No need a high speed motorway drives in this case on nearly new cars. 
Just the car needs to be ON ( ready mode) for longer and it will settle down itself. Good practice to keep ON for at least 20-30 min after each start up to allow sufficient time for the hybrid system to recharge the batteries. No need to worry about overcharge or complete discharge, the car does everything by itself. One thing to note when arriving at your destination and the engine kicks in to recharge the Battery, do not turn off your car , wait engine to shut off itself and then turn off your car. 

[yavli]

Guys I really appreciate your time. I followed both the "B-trick" and a 45 min ride on the ring road of my city and the car found itself back!

As a newbie in hybrid systems I'm still trying to understand how this thing works. After some long trips (300-400km) in August (I bought the car at August 1st), in September-October I got back to work and started the short everyday rides.

Tony is this 20-30min operation necessary after EVERY start up, or once-twice a week is enough?  Also could you explain what exactly do you mean by "sufficient time for the hybrid system to recharge the batteries"? The system needs to fully charge the hybrid Battery every time it starts? Finally: has the GPF anything to do with the need to drive for longer periods?

[Cyker]

1 hour ago, yavli said:

has the GPF anything to do with the need to drive for longer periods?

that's my current theory as if I do longer drives regularly I almost never get the engine-running-for-no-reason thing, but if I only do low-speed/stop-start driving for a week then it does it much more frequently.

the theory is the GPF is trying to regenerate, but at low speeds the engine isn't putting enough fresh air into the exhaust so it has to run for longer. B-mode turns the engine into a very inefficient air pump, so when you let off the accelerator it pumps lots of fresh air into the exhaust, allowing the soot traps to burn themselves clean.

[SouperChris]

If you're getting very good mpg (hi 60s) it should all be fine. Check the app for proportion of ev use

[TonyHSD]

The 20-30 min ON time is only if it’s possible and recommended., not absolute must have.
The idea here is to give the car time to recharge the batteries. 
The 12v Battery needs these 30 min to get sufficient charge to maintain its health.
If you do exclusively short trips less than that in short period of time this Battery may even die and you will need to jump start. 

For the hybrid Battery the charge level itself it’s not a problem but the battery conditioning is, this means each individual cell voltage needs to be similar or the same. This happens with repeated charging and discharging cycles. The car hybrid system does that when the car is ON and while driving.
When you only drive short trips the car has no enough time to complete these charges and discharges cycles to condition the hybrid battery and this is the reason why engine is constantly ON, the engine can be working to charge the battery but also to discharge it.
Some owners never knew about this , others never noticed.
Low state of charge on any of the batteries  in Toyota hybrids is the main reason engine to behave strangely and be on constantly.
I have thoroughly explained these processes in the post shared above by other members. 
GPF regeneration is eventually possible although in official Toyota documents is noted that this is not necessary and it’s only a thing on Diesel engines, plus gpf flow is monitored by sensor and in a event of blockage there will be warnings on dashboard similar to Diesel engines. 
Forcing in B mode will affect battery conditioning because B mode add extra regenerative braking and extra charge to the battery and at the same time discharge is also accelerated. These are processes that comes with extra heat and stress which may reduce the overall efficiency, that’s why Toyota does not recommend using B mode as default driving mode. 

Finally to prove this is correct I can give an example my car that does not have electronically monitored gpf has had exactly the same behaviour previously and the reason was bad battery.
After replacement and because I drive a bit more never ever this car had any abnormal engine behaviour. 
 

[yavli]

wow Tony thanks for taking the time for this thorough explanation - illuminating!

[TonyHSD]

8 minutes ago, yavli said:

wow Tony thanks for taking the time for this thorough explanation - illuminating!

My pleasure.