Resetting the ECU in Gen 6 Camry

[Tash]

Hi all, this may sound like a strange ask for a newer car, I don't know - but does anyone know how to go about resetting the ECU? And is it something that can be done easily or does it require dealer intervention??

The reason I ask is because of absolutely woeful fuel economy (in my eyes) on 98 premium of all things, a couple of people have suggested maybe the ECU doesn't know what to do with it?? On the way up to Sydney, I used regular unleaded, so I filled up again in Lavington which was around 540-550km from Sydney and when I got there I still had more than a quarter of a tank left, so with a 70 litre fuel tank that was roughly 20 litres left (a quarter being 17.5).

On the way back, I persisted with the premium (which I used on the cruise as well - and was very unimpressed, it sucked through the fuel like an absolute demon) and got the same 540 odd kilometres to 45.19 litres, again stopping in Lavington, at the exact same place, to fuel up again. Shouldn't premium save me a lot more? Now I'm no good at math's so someone please feel free to do the calculations for me. After I filled up, I got to Bright (less than 100km), Stanley and back to Bright (about 70km) and back to Bendigo (300km), so around 500km and when I got back to Bendigo my fuel gauge only read I had 1/4 of a tank left.

Now it has me really curious cos I thought my fuel economy should be A LOT better - the digital display on the dash was reading fuel consumption at like 7.6lt most of the time, but if I do the calculations thats not what I'm coming up with. And you can't put 45 litres into a tank if there isn't room to fit it... I have checked the car briefly too and I cannot see anything leaking either. So far, I have gotten better k's using regular unleaded.

Any suggestions anyone? Not sure whether it is worth running fuel injector cleaner through the car as well, or whether the 4th tank of 98 premium might be better??

[Andrew357]

With regards to fuel consumption, you may not get better fuel consumption from premium but you may benefit from the additives they put in it.

As we discussed in Sydney, the 2AZ-FE won't 'perform' better on running on Premium98 all the time; but it would be beneficial to run it once every 4th tank or something like that to help clean up/keep the engine clean. I'd personally run it 1 to 2 just to keep the engine clean, although WHEN you get boosted you will want to run 98 ALL the time :)

If you wish to reset the ECU do the following:

1) Remove the negative battery terminal and leave it off for ~30mins

2) Put the battery terminal back on

3) Start the car and let it do the normal startup (Airbag lights etc), run the car @ idle for 10mins

4) Remove the negative terminal for a 1/2 a minute

5) Replace the negative terminal and off you go

6) Drive

Go nuts, the car will learn your driving style!

[DJKOR]

What Andrew said above is good with respect to the ECU reset so I will leave it at that.

So instead, I will comment on the fuel side of things. The following is my own personal observations and opinions, don't exactly take it for truth.

When it comes to highway driving where you only use the lower half of your engine range most of the time, I would imagine that there would be no difference economy wise when using E10, 91RON, 95RON, and 98RON on a car that is built to run on 91RON.

My own understanding of the octane rating is that the higher the octane, the less resistant to knocking due to compression. Now when you are casually cruising along, your engine is not going to be running at any form of extreme that would require the extra 'abilities' of a higher octane fuel. Therefore, in theory you should be getting the same highway fuel consumption with either grade of fuel.

I found this true with my old Aurion. As said, this is my own experience. Driving interstate with highway only driving, I tested E10, 91RON, 95RON, and 98RON and found barely no difference between them all. Any variation I found could have easily been the result of getting a little happy with the accelerator.

That said, I have also heard that you have to give it a couple of tanks or more for the engine to make significant enough adjustments to give you that little bit more fuel economy. Even still, I wouldn't be expecting that much of a difference with fuel economy in this scenario.

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Other note: if you haven't picked up on it yet, your fuel gauge from full to empty should read about 60 litres. The last 10 litres, it doesn't really register. So when you said you arrived in Sydney with a bit more than a quarter of a tank of fuel, you would have had at least 25 litres or so left in the tank. That means you used about 45 litres to get there which seems to match what you used on the return trip.

If you need to do some more detailed calculations, reset your trip meter every time you fill up, then when you fill up again (to the same full level*), write down the trip meter reading on your receipt. Then when you get the chance, take the litres of fuel you bought, divide it by the kilometres you wrote down on that receipt, then multiply the figure by 100. This will give you your l/100km value.

* I determine full by pumping till the first click, removing the nozzle, waiting about 10 seconds, putting it back in and pumping till it clicks again. Then I usually round to the nearest '5 cent rounding'.

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Edit: 45 litres per 550km equals about 8.18l/100km. That's about what my old Aurion did on the highway when keeping to the speed limit. I hear the Camry has about the same consumption.

[Ronnyboy]

I agree with Andrew and Daryl.

On the other hand you can try one of those Rip off fuel Injector services that the dealer offers or use the Fuel Injector System cleaners.

The Calculations you mentioned sound about right :)

Edited June 22, 2010 by Ronnyboy

[Silver-Aurion]

Thats pretty poor for a 4 cylinder. I found that there is no point in getting a big car like the camry 4cyl because it will most likely use the same amount of fuel as its v6 counterpart and the v6 might use less fuel on the highway/freeway since it sits on lower rpm.

I had a camry 4cyl and it would drink fuel more then my aurion which is where i learnt my lesson to not bother with a 4cyl, but these are just MY observations.

In regards to ECU reset, I did not notice any change but the main difference I noticed was the high smell of burnt petrol coming out of the exhaust on cold start ups.

I've been filling 98BP ever since I got the car (so thats 6 months of BP98 and nothing else) and I would always get a strong petrol smell when i would start the car. After the ECU reset there was virtually nothing at all. Maybe the car decided to adapt to the different fuel mixture and configured itself with that? Not sure but it made a difference to the petrol when starting the car.

Also now for the last 6 refills I've been using fuel doctor as recommended by djkor.

my 2cents here.

[private number]

Tash im gonna chime in here.

I was getting approx low 9 litres per 100kms out of the tank. At the moment the empty fuel light came on at 560kms using BP ultimate this week. That being said, there is roughly 15litres left in the tank (and my ride is automatic with a mixture of granny and lead foot driving)

Other than resetting the ECU (which someone already told you how to do it), maybe a service is due soon? Or maybe you needa run a injection cleaner? Apparently im due for one soon (next service a long with spark plugs) which will improve my fuel economy. For some reason, the weeks following up to my service i was getting on average about 10 litres per 100km.

Also something else i found interesting is the weeks (and every week after) after i changed my muffler, i noticed my fuel economy got instantly better. Before the muffler change i was getting 11-12 litres per 100km (real shocking). Im not sure if its mainly because of a muffler change, but this is my observation and couldnt think of anything else that had changed (same habbits, same driving, roughly same amount of kms traveled each week).

Just some food for thought

[Tash]

Cheers for the replies everyone - it confirms what I had going around in my head; it just didn't really seem natural I guess to get less km out of a tank of premium than it did a tank of unleaded. But Daryl you've helped put that into perspective for me a lot, especially in regards to the freeway driving; I guess I would be seeing a lot more benefit to it say in a cruise/country road scenario with a lot of speed variation etc and as you said Andrew the cleaning benefits out of it. Thanks too for the instructions on resetting it if need be :)

The car is due for a service as well which is my next problem - finding a reputable mechanic in Bendigo! Think I will just go back to 91 unleaded, let this last bit out - so Daryl that was interesting to note about the fuel tank, so effectively when the fuel empty light comes on, it's telling you that you have about 10 litres of petrol left? The empty light came on whilst I was in Sydney running 98 and reckoned I only had 50km to travel..

Very interesting about the muffler change Reece - although was that a hint for me?? Hahaha - if so, I'm getting there :)

[private number]

Haha it wasnt a hint for you tash, but now it is LOL.

[DJKOR]

... so Daryl that was interesting to note about the fuel tank, so effectively when the fuel empty light comes on, it's telling you that you have about 10 litres of petrol left? The empty light came on whilst I was in Sydney running 98 and reckoned I only had 50km to travel..

Your mileage may vary (no pun intended), but with my Sportivo and TRD which I would assume behaves exactly the same with reading fuel level, from the moment the fuel gauge is on empty and your cruising range says '0km', you will actually have anywhere between 10 and 12.5 litres or so left in your fuel tank. This is why I mentioned that the gauge only reads the last 60 litres of the tank.

So if your fuel light comes on when your cruising range says you have 50km remaining, you will have about 18-20 litres of fuel left or approximately another 120-150km of driving remaining. Last time I tested this out, I travelled another 80km on empty and still had a few litres left in the tank.

[Andrew357]

... so Daryl that was interesting to note about the fuel tank, so effectively when the fuel empty light comes on, it's telling you that you have about 10 litres of petrol left? The empty light came on whilst I was in Sydney running 98 and reckoned I only had 50km to travel..

So if your fuel light comes on when your cruising range says you have 50km remaining, you will have about 18-20 litres of fuel left or approximately another 120-150km of driving remaining. Last time I tested this out, I travelled another 80km on empty and still had a few litres left in the tank.

I did this as well on the way down. Computer said I had 22km remaining and by the time it said 17km remaining I had done ~35km and arrived at Tamworth in the nick of time :)

[Tash]

Well thank you both for answering my blonde moment :) Although that is pretty confusing!! Currently my range reckons I've got 87km left and the needle is getting closer to the empty mark, so in effect I've probably got more like 150km left to travel. Was so much simpler in the old Gen 3 when empty meant empty!!

[DJKOR]

Well thank you both for answering my blonde moment :) Although that is pretty confusing!! Currently my range reckons I've got 87km left and the needle is getting closer to the empty mark, so in effect I've probably got more like 150km left to travel. Was so much simpler in the old Gen 3 when empty meant empty!!

The fuel gauge in these cars can vary quite a little, but most of the time I can guarantee you that the moment your cruising range says 0km and your needle is right on the empty line, you will have at least 10 litres left. After the many tanks of fuel I put into my Aurion ($11,000 spent) I had never come across a case where I could fit more than 60 litres into a tank when the needle was on the empty line.

Usually if you driving isn't always constant (not all highway driving etc), the gauge may be slight more inaccurate.. but just a little. Using my attached photo for reference, my needle hit the empty line (as well as the cruising range saying 0km) at around 601km on the trip meter. As you can see in that photo, I had travelled another 51km and I filled up at a servo another 2 or so kilometres away. When I filled up, I only put 59.86 litres of fuel into the tank. So at that going rate, with my needle lower than the empty line, I still could have travelled for another 100km.

So whenever your fuel gauge shows empty, there is no need to panic because you will have a bit of fuel to hopefully get you to the next servo.

A little bit sidetracked, but I found a sweet spot with my car. Between 80-90km/h at constant speed it seems to be it's most efficient. This was an average figure after driving for about 210km. I reckon if I kept driving non-stop at that pace, I could have maintained that consumption. I have found my trip computer to be off by about 0.1-0.2l/100km on average, so even with that factored in, it's not bad for a supercharged V6: