PHEV - ICE doesn't stop in HV mode

[spicyhotone]

Over the past few months, I've had very little cause to use the ICE, almost totally electric powered journeys. On Sunday, a slightly longer journey started with a partly charged Battery meant I had to switch to HV mode over a 20min or so stretch of motorway (I had about 10 miles of Battery range remaining at this point). I noticed as I drove that the engine wasn't cutting out once the accelerator was released and the Battery was in recharge mode (eg. downhill sections). When I came off the motorway and had to stop for a minute or two at traffic lights, the engine still didn't stop, which was most unusual. When I finally returned to EV mode, the engine took 10-15 seconds before it finally decided to stop.

Any idea what was going on here? Outside temperatures were pleasantly warm (low 20's C), battery had a reasonable amount of charge, and the engine must have been up to full operating temperature after 20mins of motorway driving. It felt almost like a DPF refresh cycle on a diesel car - I don't know if the RAV4 PHEV has a petrol particulate filter, and if so, if they have such pronounced refresh cycle as a DPF has? Or is there another explanation?

[kucyk]

If it was a one time event, I wouldn't worry about that. Even Toyota won't be able to tell you what and why was that. Maybe the engine needed some time to cool down?

[ernieb]

Once the ICE starts it goes through a cycle to circulate the oil and fully warm up.  It’s frustrating when you have a full traction Battery and encounter a steep hill even with careful brake application and regeneration the ICE will kick in to enhance the braking effect. It then runs until it’s cycle is complete.  Cold winter days it’s a long time. Whilst this is going on it will charge the Battery and/or provide drive.

[spicyhotone]

Yes, I'm aware of this normal cycling, getting up to temperature. But normally I observe that takes 5 minutes or so of motorway driving in HV mode, and then engine will go off once power isn't required. I'm not that worried about it (as long as it doesn't continue behaving like this!) but was curious as to what's going on. 

[Roger_N]

3 hours ago, spicyhotone said:

and the battery was in recharge mode

Did you select recharge mode, I think you can do this with a PHEV as this will run the engine to top up the Battery, which I believe  it will not get to a full charge under normal conditions.

[ernieb]

39 minutes ago, spicyhotone said:

Yes, I'm aware of this normal cycling, getting up to temperature. But normally I observe that takes 5 minutes or so of motorway driving in HV mode, and then engine will go off once power isn't required. I'm not that worried about it (as long as it doesn't continue behaving like this!) but was curious as to what's going on. 

Don’t forget that if the ICE does not fire against an internal schedule it will be made to fire to run the engine and circulate the fuel. So even if you always have traction Battery energy to spare every now and again the ICE will fire.

[Gray86]

GPF (gasoline particulate filter) probably due a regen. Happens on my corolla hybrid, engine running when you wouldn’t expect it to 

[Nick72]

10 hours ago, spicyhotone said:

Over the past few months, I've had very little cause to use the ICE, almost totally electric powered journeys. On Sunday, a slightly longer journey started with a partly charged battery meant I had to switch to HV mode over a 20min or so stretch of motorway (I had about 10 miles of battery range remaining at this point). I noticed as I drove that the engine wasn't cutting out once the accelerator was released and the battery was in recharge mode (eg. downhill sections). When I came off the motorway and had to stop for a minute or two at traffic lights, the engine still didn't stop, which was most unusual. When I finally returned to EV mode, the engine took 10-15 seconds before it finally decided to stop.

Any idea what was going on here? Outside temperatures were pleasantly warm (low 20's C), battery had a reasonable amount of charge, and the engine must have been up to full operating temperature after 20mins of motorway driving. It felt almost like a DPF refresh cycle on a diesel car - I don't know if the RAV4 PHEV has a petrol particulate filter, and if so, if they have such pronounced refresh cycle as a DPF has? Or is there another explanation?

If the ICE kicks in of its own accord or I put it in HV mode manually then switch back to EV mode the car continues in ICE mode for anywhere between 5 and 10 minutes in my experience. As Ernie says, it has to go through its cycle. What can be confusing is the car MID shows EV mode even though the ICE is running. Always find that weird.

[Lawnmowerman]

20 minutes ago, Nick72 said:

If the ICE kicks in of its own accord or I put it in HV mode manually then switch back to EV mode the car continues in ICE mode for anywhere between 5 and 10 minutes in my experience. As Ernie says, it has to go through its cycle. What can be confusing is the car MID shows EV mode even though the ICE is running. Always find that weird.

Yup, I've seen that too. Looking at the energy monitor it shows both powering.