Options to reset ECU

[agent_dess]

Folks,

I have a 2015 IS300h ands want to reset the ECU, normally i would pull the negative terminal on the 12v Battery and leave it for a while.
But i am apprehensive on doing this in case the radio goes to heaven 👻

Was the radio dying issue only effecting 2013/2014 models?

How else can i reset ECU?

[NemesisUK]

Just curious but why do you want to reset the ECU and which ECU are you referring to?

[agent_dess]

15 minutes ago, NemesisUK said:

Just curious but why do you want to reset the ECU and which ECU are you referring to?

I want the ECU to learn (re-learn) my driving habit, still can seem to get above 35mpg, looking at the historical record the previous owner seemed to be getting 38-44mpg no bother.

[rayaans]

The radio issue was mainly on the 2013/14 models. If you have the matt plastic trim on the AC control area, it likely wont be affected. 

Im not entirely sure if resetting the ECU will make any difference. It may do on a vehicle with a torque converter by re-learning shift points etc but you dont have those with a the e-cvt

Poor MPG is almost entirely caused by driving habits including journey length. Obviously mechanical issues, poor fuel and different oil grades will cause it too along with tyres. 

If you've eliminated those you could try the Battery method or pulling EFI and ETCS fuses.

[NemesisUK]

3 hours ago, agent_dess said:

I want the ECU to learn (re-learn) my driving habit, still can seem to get above 35mpg, looking at the historical record the previous owner seemed to be getting 38-44mpg no bother.

The ECU would normally relearn very quickly as you drive but as Rayaan points out this may not be the case in a car with e-CVT transmission.

How long have you been driving this car? Can you be sure you are driving the same sort of journeys as the previous owner?

[Linas.P]

As other said, I doubt it is ECU that is causing your MPG to be higher. And in my experience 35MPG is completely plausible on IS300h, especially considering it is F-Sport on 18". I haven't even seen any better myself, but I have lead foot so I always knew it is down to my driving habits. At the same time it is possible previous owner got 38-44MPG from it, if the car was driven at exactly 70MPH on motorway most of the time.

[agent_dess]

4 hours ago, NemesisUK said:

The ECU would normally relearn very quickly as you drive but as Rayaan points out this may not be the case in a car with e-CVT transmission.

How long have you been driving this car? Can you be sure you are driving the same sort of journeys as the previous owner?

6 months now... i do note that on longer journeys i get better mpg than my usual daily 4 mile run.
looking on Fuelly maybe my average is not all that bad.  I do wish i would get 40+ 🤖

[Linas.P]

1 minute ago, agent_dess said:

6 months now... i do note that on longer journeys i get better mpg than my usual daily 4 mile run.
looking on Fuelly maybe my average is not all that bad.  I do wish i would get 40+ 🤖

On 4 mile run you are quite lucky to get 35MPG to be honest, car hardly even gets warm in such a short run. So here is your explanation from MPG - short journeys!

[J Henderson]

Agreed, that journey is too short to get a true picture.

My journey to work is around 12 miles, mostly on A road and Motorway and I'm almost there by the time the car is operating with proper efficiency.

 

[agent_dess]

Ok well thats reassuring I suppose lol

 

 

[Thackeray]

Look at the minute by minute fuel consumption monitor display. Typically, I see around 20 mpg for each of the first five minutes while the engine warms up. It then starts to move up to around 40 or more on longer journeys.

But in the winter it takes around 7-10 minutes to get up to normal temperature and the low mpg continues during that time. There was a period when I was doing short journeys - four miles there, wait four hours during which the engine cooled down, then back another four miles. I was getting little more than 30 mpg during the winter, with all the accessories turned on - heated seats, headlights, wipers, screen demist etc.