Just Reset My Ecu

[nevarthur]

Done it about 5 minutes ago!

I've been fascinated by all the talk of resetting the ECU in various posts that occur from time to time. So finally, bearing in mind that I'm a bit of a numpty when it comes to mechanical stuff, I've had a go!

So far, I haven't driven the car, so I'm curious about whether I will feel a difference, or whether I will notice a difference in the MPG. I just returned from driving the car down to Tuscany which was a round trip of 2021 miles, and my MPG was 33 for that trip. I'm actually quite a slow and smooth driver so I'm surprised it was as low as that but various trips into the mountains on tiny roads, and crossing the Alps at altitude probably didn't help the fuel consumption.

Anyway, if anyone's interested, I'll post my impressions.

Cheers, Nev

[DINGER]

Hi mate, from what ive read on other posts it will take a couple of full tanks before you will get any result.

I have been meaning to reset mine, so keep us posted and let us no how you get on.

[Scorps01]

Air con on will have an affect on your MPG.

[littlelegs]

Air con on will have an affect on your MPG.

with the air con on it will have little or no diffrence to your MPG

[Noel]

Air con on will have an affect on your MPG.

with the air con on it will have little or no diffrence to your MPG

Sorry but you're mistaken.... anything that puts extra load on the engine has an effect on MPG, even the rear window demister has an effect :winky:

[Scorps01]

Air con on will have an affect on your MPG.

with the air con on it will have little or no diffrence to your MPG

Your so wrong!!!

Did you see the top gear programme.......Audi V8 Diesel from London to Edinbugh and back on a full tank of diesel, he would only of done it if EVERYTHING was switched off... :D

[VVProtocolVV]

Air con on will have an affect on your MPG.

with the air con on it will have little or no diffrence to your MPG

Your so wrong!!!

Did you see the top gear programme.......Audi V8 Diesel from London to Edinbugh and back on a full tank of diesel, he would only of done it if EVERYTHING was switched off... :D

everything switched off and travelling at about 40mph, and no traffic jam...

[Scorps01]

He got better MPG using his foot on the throttle rather than using cruise control. :D

[nevarthur]

Air con on will have an affect on your MPG.

with the air con on it will have little or no diffrence to your MPG

Logic suggests to me that if the compressor is working off the engine, and I can hear the engine load up when the aircon kicks in, then surely the engine must be working slightly harder. However, it would be impossible to quantify unless you had a control car with no aircon and all other factors remained the same. My personal feeling is that the small amount of extra fuel used is worth it for the comfort of having a nice temperature in the car. I do wonder how much extra fuel the car would use towing the dodgy aerodynamics of open windows down the road so I'm sure that must offset the aircon fuel a bit.

At the end of the day it's hardly worth falling out over it.

The car I own is a 2001 SE Auto and it only had one owner before me, so I'm assuming if my driving style is radically different to his, then I may see some sort of difference in MPG or performance having reset the ECU.

Nev

[Scorps01]

But as mentioned b4 it will take a couple of tank fulls to recognise your style of driving.

[KnightUnit]

Air con on will have an affect on your MPG.

with the air con on it will have little or no diffrence to your MPG

Your so wrong!!!

Did you see the top gear programme.......Audi V8 Diesel from London to Edinbugh and back on a full tank of diesel, he would only of done it if EVERYTHING was switched off... :D

Really?! Did he do it with the air con on then and did not make it?! I must have missed that.

I have had my is200 over 3 years and done more then 70,000 miles. I have done air con on, air con off, snow button etc for numerous tanks of fuel and can confirm that running the air con all the time has no noticeable effect on mpg. I get around 425 miles per tank with a/c on all the time.

[Jackal321]

i reset my ecu about 2 months ago, i fill up my tank almost every week and i've not noticed anything different....

[The Transporter]

Anything that adds a load to the engine WILL affect the amount of fuel consumed to meet that load..You don't get 'owt for nowt. As has already correctly been stated, leaving electrically powered systems on will make the alternator need to supply more power and since this is driven by the engine has an effect on the amount of fuel that the engine must burn to supply what is required.

The Air con compressor compresses refrigerant to high pressures and to do this requires the engine to work just that little bit harder and use more fuel... The warmer the ambient temperature the longer the compressor runs for.

The general rule of thumb suggests that an open window uses less fuel than an aircon at speeds up to 40mph, after that the drag of the open window causes the aircon to have the advantage..This is however dependant on many factors and is just a rough guide and quite frankly if I was concerned over a small percentage then I would not be driving an IS200 which is not exactly the most frugal vehicle in the 2000cc bracket. I'll keep my windows shut thanks

[RedLexus]

........ quite frankly if I was concerned over a small percentage then I would not be driving an IS200 which is not exactly the most frugal vehicle in the 2000cc bracket. I'll keep my windows shut thanks

Took the words out of my mouth! However I have noticed eff-all difference in mpg driving with the aircon on or off. I think it makes a greater difference on small engined cars that have say 50-70 bhp , the approx 5bhp or so driving the aircon is a much larger percentage of the total engine output.

[DJ Wozza]

Really?! Did he do it with the air con on then and did not make it?! I must have missed that.

I have had my is200 over 3 years and done more then 70,000 miles. I have done air con on, air con off, snow button etc for numerous tanks of fuel and can confirm that running the air con all the time has no noticeable effect on mpg. I get around 425 miles per tank with a/c on all the time.

He did it without air-con & heated seats too, it all takes power as the engine drives a higher load through the alternator

thus affecting fuel economy. I have been told Air-Con can take between 5-8% more petrol than with it off.

425 miles per tank ?

Wish my IS200 sipped petrol like that :D

[KnightUnit]

Really?! Did he do it with the air con on then and did not make it?! I must have missed that.

I have had my is200 over 3 years and done more then 70,000 miles. I have done air con on, air con off, snow button etc for numerous tanks of fuel and can confirm that running the air con all the time has no noticeable effect on mpg. I get around 425 miles per tank with a/c on all the time.

He did it without air-con & heated seats too, it all takes power as the engine drives a higher load through the alternator

thus affecting fuel economy. I have been told Air-Con can take between 5-8% more petrol than with it off.

425 miles per tank ?

Wish my IS200 sipped petrol like that :D

Im not sure if they mean 5-8% for older cars with air con units, but I can say I have never noticed a difference.

I know it takes a higher engine load to drive this stuff I never said it did not, but what im saying is for the sake of no noticeable difference on fuel economy to have the a/c on (well in my is200), why not use it. Gets to stuffy without it.

[The Transporter]

The aircon system on the IS200 is pretty much out of the steam age using a fixed displacement cyling clutch compressor (Runs at either 0% or 100%) and I love it for that ...Good old solid meat pie air conditioning design. Not so efficient in our temperatures but unbeatable when it is really hot and far simpler to repair. More modern designs us what is called a variable displacement compressor which adjusts itself to the amount of cooling that it needs to do..Great in theory and they can work well in Europe but the compressors are more prone to failure..Ask anyone who has ever owned a VW Sharan.

The latest "Clutchless" compressors run at 3% of their total output..Even when switched off but give very accurate temperature control and dehumidification and are efficient at lower outputs but fall down badly when it is really hot.

Because the IS is a pretty thirsty car the chances are that very little will be noticed in fuel consumption..so run it and enjoy.

The little 1.3 Toyota Tercell that I ran in Dubai some years ago would lose 5kph off its top speed due to the aircon.. but I was nice and cool and that is what mattered to me.

[boddamloon]

i agree the AC heated seat etc etc all uses extra power but if you driving at 50-70MPH i can see it making much difference. And if it does it will be so small you are never going t notice it. Its like saying if you fill your tank all the way to top compared to half your carrying extra weight. What weight have you got in your boot etc? There all factors. I have reset my ECU in the past and i cant say i have noticed any noticble difference.I say keep running your car using the comforts and enjoy

[WylieCoyote]

I've done the aircon/no aircon test in every single one of my cars more times than I care to mention. My driving style is smooth and I don't thrash cars and I can say hand on heart I've never noticed the slightest difference regardless of a/c or not. I agree it does make the engine work a bit harder, but for me, that extra work doesn't translate into fewer mpg. Oh and if you're bothered about getting an extra 1mpg for having the a/c off, it kinda defeats the object of having a nice car.

Keith :)

[littlelegs]

I've done the aircon/no aircon test in every single one of my cars more times than I care to mention. My driving style is smooth and I don't thrash cars and I can say hand on heart I've never noticed the slightest difference regardless of a/c or not. I agree it does make the engine work a bit harder, but for me, that extra work doesn't translate into fewer mpg. Oh and if you're bothered about getting an extra 1mpg for having the a/c off, it kinda defeats the object of having a nice car.

Keith :)

good point

if you is that worred about it read this

http://www.honestjohn.co.uk/faq/faq.htm?id=14

[The Transporter]

Hmm some useful stuff there, but also a lot of BS. The idea of air and water passing from the atmosphere in to a pressurised system is an old wives tale. Similarly if your aircon is on then there is no need to turn the temp to full cold as the refrigerant is circulating anyway. I've never seen a modern ac system rot out from the inside out, always from the outside in, normally from the manufacturer using steel in close proximity to alloy

[nevarthur]

Hmm some useful stuff there, but also a lot of BS. The idea of air and water passing from the atmosphere in to a pressurised system is an old wives tale. Similarly if your aircon is on then there is no need to turn the temp to full cold as the refrigerant is circulating anyway. I've never seen a modern ac system rot out from the inside out, always from the outside in, normally from the manufacturer using steel in close proximity to alloy

I like your posting style, and you seem to know what you're on about. As regards my reset, I've just got back from Cambridge, and I've done 300 miles since putting in the maximum fuel I could. A big change for me is that the fuel gauge needle is only just registering under the halfway mark, rather than hovering somewhere around the quarter mark as I would expect for the kind of driving I've done this weekend. (Mostly at 70 mph with the cruise control on). I also feel, and I know it's very subjective, that the car is slightly more responsive.

For the sake of giving an accurate picture though, I feel I should say that I filled up in France with 98 RON juice rather than my normal 95 RON, and then when I got back home to Ashford I topped up with around a hundred miles worth of 95 RON. Then I pulled out the 2 fuses mentioned on the forum, and left the car for 10 minutes before returning them.

I swear I can feel a difference, and think I may well fill up again from now on with 98 RON. Honestly, even though it might be wishful thinking, the car feels really good.

For myself, so far, I'd recommend resetting the ECU.

Nev

[ibby]

what alot of the guys are missing is

all ecus "learn" new settings when the fuses are pulled out.

they continuesly learn.. adapt with fuel and air..

Too be honest I dont think you will noticed much,

if any at all.

as for the RON argument, with out proper tuning.. you will never maxumise the fuel / air ratio.

[TigerFish]

Assuming the IS's work the same as the GS's, I think the main thing that the reset does (most noticeable) is for those with auto gearboxes. It will relearn your driving style and change gear accordingly. If like me, you bought your car from someone who obviously never put their foot down, it made a huge difference in the non "pwr ect" mode. The car was much more responsive and was more eager to change gears instead of struggling in the wrong one. That made the car feel much more responsive after the reset.

[nevarthur]

Assuming the IS's work the same as the GS's, I think the main thing that the reset does (most noticeable) is for those with auto gearboxes. It will relearn your driving style and change gear accordingly. If like me, you bought your car from someone who obviously never put their foot down, it made a huge difference in the non "pwr ect" mode. The car was much more responsive and was more eager to change gears instead of struggling in the wrong one. That made the car feel much more responsive after the reset.

I don't actually know if the IS200 auto is an adaptive box. Please does anyone else know? Otherwise, I will hunt out the owner's manual and see if that says.

Cheers, Nev