MPG MPG after ECU reset

[KevinF]

To City Motors, Basingstoke Honda dealer this morning with the 2.2 Sport for the steering pump recall. I asked if they could take a look at the creaking windscreen at the same time, and queried the way fuel consumption according to the trip computer has fallen off as the car approaches its first service. I also asked if they could check the aim of the headlights.

Collected this afternoon with a new steering pump, windscreen clips 'adjusted', headlights now properly aligned (boy, what a difference!) and a reset ECU. Fuel consumption on the way there was 51.4 - on the way back, in more stop-start traffic, 59.8. Now that's what I call a result. The car also feels more lively than it did before.

A few people here have noted that the ECU can be reset by disconnecting the battery for a time - and that the car is often quicker after such treatment. But I wonder if anyone else has noticed better fuel consumption?

I also wonder if those here who complain of average MPG in the region of 38-40 might find their cars benefit from a reset.

I further wonder if the reset DOES actually affect fuel consumption, or whether it actually only alters the calibration of the trip compter functionality and thereby deceives. Only a brim-to-brim fill will show - and I'll do that over the next fortnight.

KevinF.

[PTR]

probably they've not just resetting but upgraded the ECU software...
I don't think a simple reset would bring that much... but you never know...

[pcr]

KevinF,
Are you suggesting that the trip computer does :-
MPG = (Miles / Fuel) x upitabitfactor
Who would do such a thing ?

[Miggins]

Originally Posted by KevinF

I also wonder if those here who complain of average MPG in the region of 38-40 might find their cars benefit from a reset. KevinF.

I've had mine back from its first service now for over a week and the mpg hasn't changed a bit - it's going back in in a week so I will mention that it's still down in the LOW 30's which it dropped to in the last 1000 miles before it's service (from high 30's - heavy foot I know!).

I'll be interested to see what you get brim-to-brim Kevin.

[IWANTACIVIC]

low 30s in the cdti , what you got lead foot ???????????? must be the remap and you useing the power more , did you notice it drop or raise after reamp ? or have you not had time to check doing warp factor 9 all the time in your spaceship . Why dont you try batt' of reset ? see if it makes any diffence. mite say trip to dealer.

[basegreen]

It depends on your usage pattern. Someone doing a lot of motorway driving is clearly going to do far better than someone doing lots of turbo, urban and short trips.

[Miggins]

Originally Posted by IWANTACIVIC

low 30s in the cdti , what you got lead foot ???????????? must be the remap .......

Not remapped - only desired

Originally Posted by basegreen

It depends on your usage pattern. Someone doing a lot of motorway driving is clearly going to do far better than someone doing lots of turbo, urban and short trips.

Journeys now are shorter - usually 20 miles of back roads. I'm not surprised at it being low compared to others but I am surprised at how low it is. Usually a service helps!

May be down to the fact they put the wrong oil in - 10W40 instead of 0W30. Still surprised at the difference though.

[platk]

Originally Posted by Miggins

Not remapped - only desired



Journeys now are shorter - usually 20 miles of back roads. I'm not surprised at it being low compared to others but I am surprised at how low it is. Usually a service helps!

May be down to the fact they put the wrong oil in - 10W40 instead of 0W30. Still surprised at the difference though.

Interesting.. I've just been to my dealer for some 0w30 but they dont keep it, and I can't find any elsewhere. They only keep 10w40 because it is compatible with both petrol and diesel so they say.
They also assure me there is no problem mixing it whatever was put in at the factory. Why do Honda recommend 0w30 ?

[echo seven]

Hi all,

The reset thing is interesting - I'll think I'll try it anyway. On my first few tank fulls i was geting 45mpg, even 55mpg on a long run on country roads where the top speed was about 50mph. Now with the same driving pattern its about 38 - 40 mpg. This is after 4 months and 6K miles. Its strange as i remember someone saying the mpg should go up and the milage goes up and the engine loosens up, but for me, its the othr way round!

Cheers
Les

[pcr]

Echo seven, I may be wrong here, but in my experience fuel consumption gets worse when the cold weather arrives.

[Brian]

Would agree with the cold weather theory. My fuel economy dropped in the recent cold spell over Xmas to about 45-46 mpg in my ex diesel.

[Miggins]

Originally Posted by platk

Interesting.. I've just been to my dealer for some 0w30 but they dont keep it, and I can't find any elsewhere. They only keep 10w40 because it is compatible with both petrol and diesel so they say.
They also assure me there is no problem mixing it whatever was put in at the factory. Why do Honda recommend 0w30 ?

Hi platk
Well not only do Honda recommend 0W30 they DON'T recommend 10W40 for the diesel! Checked with Honda UK and they actually stated it as being the wrong oil.

There is also the matter that 10W40 is probably a lot cheaper than 0W30 fully synthetic - this is probably the reason they put it in. Cynical . . . maybe.

Mixing the oils I'm told is OK - its the fact that its the wrong grade for the diesel that concerns me!

[Dave Taylor]

Originally Posted by pcr

Echo seven, I may be wrong here, but in my experience fuel consumption gets worse when the cold weather arrives.

Not just the cold weather but winter in general, we drive along with headlights & heated rear windows on to and from work, all takes power and lowers the MPG, also for petrols (& maybe diesels for other reasons) the choke is on longer.

[generationgav]

Originally Posted by KevinF

A few people here have noted that the ECU can be reset by disconnecting the battery for a time - and that the car is often quicker after such treatment. But I wonder if anyone else has noticed better fuel consumption?

I'm not sure about this; nobody actually proved this, but it certainly works on some cars and people assumed it would also work on the Civic.

So today I went and tried it....and to be honest I've seen absolutly zilch noticable difference in MPG or performance. However this might be for a different reason.

I left the battery unplugged for about 15mins, and then plugged it all back in. The HU has completely reset itself, including my climate control level, however the dash is the same, trip a and b were remembered, as were my speed alert settings, this makes me think that an ECU reset might do the job, but the dash and therefore quite probably the ECU remembers everything even after a battery disconnect.
Obviously this could be different if left for an hour or more, but as it stands I think this is the case.
Interestingly my Civic said "Check system" with the exclamation mark when I started it up, being a bit worried I tried again and got the message, third time it was fine and must have started her up 10 times since and been fine; it probably knows that something was wrong as it lost power for a little bit.

[echo seven]

Ah OK, i think you guys have talked me out of it!

[DUNCAN]

had ecu reset by dealer no difference in mpg or performance at all .

[generationgav]

Originally Posted by echo seven

Ah OK, i think you guys have talked me out of it!

It's easy enough to do and the only downside as far as I've seen is having to reset the clock & radio presets; but that's why I think it won't work.
Does anybody know if you can request an ECU upgrade?

[Miggins]

Originally Posted by generationgav

Does anybody know if you can request an ECU upgrade?

You can always 'request' one......

Seriously, why would you want to 'upgrade' your ECU. If nothing is wrong don't go changing things. If there is a clearly identified issue that affects your vehicle and it is resolved by a later ECU revision then sure it should be applied.

Do not change something just because you can - some dealers do this on the off chance it will resolve the problem - sometimes it just causes other unrelated problems/issues and/or masks the real problem.

Do they keep a backup and would they roll it back to the previous state if it went wrong?

Now wheres that latest beta firmware update for my pacemaker??????

[Charlie]

The whole subject of ECU remapping is a little bit of an old wives tale. Dealers are able to install new software in the ECU but this would only be done in the event of a reason to do so. Don't for one minute believe you are going to get more power or better performance. These aspects of the engine software and operation are very tightly controlled by legislation and homologation. If there is an update for you car, it is probably to address a concern with error codes or to aid dealer fault diagnosis.

[Miggins]

Originally Posted by Charlie

Don't for one minute believe you are going to get more power or better performance.

Remapping was resourced out by Rover (mid 90's) to resolve flat spots and poor response from the 214. This was undertaken by a well known remapping company on more than a small number of vehicles . This resulted in better midrange and obviously pickup and acceleration.