Basic ECM Resetting

[Domnic]

Hello,
* First a basic explanation of the ECM memory. The present day Engine management systems have a flash memory. This memory stores the way the car is used (high rpm driving - low etc) It stores different variables of Airflow rate, Fuel mixture tables etc.
* This is pretty good when you carry on a new mod in your car (new ones like mondeo, accors, vtec, zen mpfi etc). For example you have loaded a free flowing filter. The ECM has the old values which doesnt change anything in the cars performance.
* What you do is disconnect your negative terminal of your battery then wait for 15mins. Then reconnect. Put the ignition on... the electronic gauges will automatically reset (not your odo reading ) the needles will go till the end and back... on a mondeo this goes upto 8k rpm hehe without the engine running.
* Now start the car and go for a fast spin for about 4 kms. The computer reads the extra airflow from the MAF then calculates for extra fuel and resets the map. The new variables are now stored. This works pretty good!. Ive seen major differences.
* Try it out. Guys with mondeo's, accords give me a pm incase you try this. As you may need help resetting your keyless entry. The Remote will work, but the auto window up etc options will need reprogramming. A simple thing. takes about 2 mins. PM me if you have any problems.

Happy Resetting
Dom

[Rehaan]

Hey Dom,

One thing ive always wondered but never managed to find out is which cars available here have the most advanced ECUs? ie most adaptive and more sensor inputs etc etc.....also which is the worst ?

cheers
Rehaan.

[kakx]

Hi DOm,

I am getting Free flow fixed in my car(M800 MPFI,6 vavle 4 speed), do i do this resetting after i get it fixed. I think i had read it on spiralmax site but dint know if i shd do it for our cars here, thanks for clearing that doubt.

Regds
Kakx

[Shan2nu]

Originally Posted by [b

Quote[/b] (Domnic @ April 19 2004,00:25)]Now start the car and go for a fast spin for about 4 kms. The computer reads the extra airflow from the MAF then calculates for extra fuel and resets the map.

Will that affect fuel efficiency when using the car normally?
Coz if the fuel map is altered, the car will start using up more fuel than it should.

Better performace means more power and more power means more fuel!!!

Regards...
Shan2nu

[normally_crazy]

Originally Posted by [b

Quote[/b] ]
Coz if the fuel map is altered, the car will start using up more fuel than it should.

shanty ,
i think u r rite abt the car using more fuel as the ecm will sense more airflow, but the fuel - air mixture i think will burn more efficiently and completely as the engine breathes better ( correct me anyone if im wrong)

so fe will be the same if not better ....thas wut i think .....

can u clear this dom ?

cheers

[Domnic]

Hey Rehaan,
The cars with the most advanced ecm's are the Mercs. Then the Mondeo, Accord. These cars ecm's even control door ajar lights!!. From example if a wire is cut to one of the rear door switches these ecm's register an error code!. These ecm's have many sensors in the engine.
a) Crank Angle Sensor
b) Camshaft Position Sensor
c) Fuel Pressure
d) Coolant Temperature
e) Knock Sensor
f) Throttle Position Sensor
g) Lamda (HEGO or Oxygen Sensor)
h) Clutch Position Sensor
i) MAF
and many more

These ecm's take readings from every aspect to control fuel mixtures and ignition timing. The engine automatically advances and retards if it detects knocks and power requirement. The oxygen sensors on these cars have 5 wire outputs.

THe worst ecm's are in the maruti bracket. These cars have a basic IC which has a few preset programs. These cars only have a Throttle position sensor, Coolant Sensor and a Oxygen Sensor!. Timing is the same old method. When these engines are cold the cmputer runs in a rich mixture to heat the car up. Then as the coolant heats up the computer reduces the fuel mixture. These ecm's sense the RPM and have a 2 squirt rythmn to the injectors. And using a constant fuel map in the ecm it according to the readings from the O2 Sensor controls the time of opening for the injectors. Thats it!

The strange thing is with cars like accord, mondeo and their advanced OBD2 & 3 diagnostics and ecm's, no common mechanic will be able to do anything to these cars. They require high end computer programs to work on the different variables. But with these software you dont even have to look under the hood. Just plug it in and read the error code. The computer will tell you whats wrong and you can just fix that. Rather than opening the whole thing to rectify a small thing.. Which our mechanics love to do

Kakx, Do try the reset. There is no harm at all in your car. But im not sure you would be able to make out a major difference as the maruti ecm's as mentioned above run on pre-programmed parameters. But do give it a shot. It might just work

Cheers
Dom

[Domnic]

To answer Shan2nu and NMCRazy,
Actually ive seen improvements in fuel efficiency. As you said the car breathes more free does create a proper mixture. When normally driving mileage does increase!. Ive seen a 2kmpl increase in mondeo's and accords after mods!.
And you can actually hear the engine sounding different after this! . And ofcourse if you like the sound you will tend to go fast and burn more fuel!.

Cheers
Dom

[Rehaan]

Hey Dom,

Great info man..thanks! You are really a wealth of first hand information on indian cars!
I wasnt aware that there was a clutch sensor!

So i am assuming you have the software for tweaking the ECUs? but im also assuming that different softwares and cables are required for each make of car....or is there a universal third party program?

cheers
Rehaan

ps - Shan2nu & NC, i guess if you dont "go for a fast spin for about 4 kms" the engine might not calculate the air/fuel mix accurately which might lead to a lean mix which would hamper performance and be bad for the engine (overheating etc).

Dom,, 1 more Q..why did u specify 4km? is that the standard "learning distance" or is it just the outside limit to be safe?

[vishnugnair]

hey dominic...
is there anything to be done for cileos..i mean can i tinker with the ecu and get like a better performance or mileage or maybe both???

thanx a ton...

[GTO]

Originally Posted by [b

Quote[/b] ]
The cars with the most advanced ecm's are the Mercs. Then the Mondeo, Accord. These cars ecm's even control door ajar lights!!. From example if a wire is cut to one of the rear door switches these ecm's register an error code!. These ecm's have many sensors in the engine.

You said it Dom, I was pleasant surprised when I read the following two error messages in my C Class, on different occasions.

1. "Wiper washer fluid below 20% level. Please refill" - This was on a outstation trip, and I tend to use the wiper/washer more often than the average driver.

2. "Rear left brake light non-functional. Please check at service station" - It was indeed not working, the bulb had fused out.

I have never needed to open the bonnet to check the oil level and other fluids. Its all done via the inter-active indash display. The more I drive my C, the more I am falling in love with it!

GTO

[aadix]

hey dom what abt the hyundais?
and diff in the std sonata and v6 sonata ecms???

[Rehaan]

Originally Posted by [b

Quote[/b] (aadix @ April 20 2004,13:21)]hey dom what abt the hyundais?

Yeah Dom,

I would be especially interested in the 1.5 accent.
(I have heard the knock sensors are prone to fail in that car)

Cya
Rehaan.

[Domnic]

Hi guys,
* Lets start from the 1st Q

Yes we do have softwares to tweak ecm functions. But there is no universal cable and software in the market though you can get universal code readers. As present day companies have adopted the OBD structure (On Board Diagnostics). So you can have an OBD kit to read these faults and codes.
The problem is that each company develop their own interface and there is no product that can help out in that matter. We just have to buy different cables and software. The cables you can make yourself simple stuff actually. Software you can get from the company directly. We can alter fuel maps, adjust Fuel types (Octane) so the timing advances. So many things. In mercs we can adjust from the number of pushes to make the window come down to single touch window down etc


The reason i suggest 4kms is coz, Actually in the first mile itself the car learns the new differences and makes changes to compensate. But due to our indian roads you will not be able to reach an average of about 60km/hr. After doing the reset if you guys start driving normally the car will automatically change to that specs . So do give that redline shift on most gears... new cars nowadays are built to great tolerances. Even running in (dont go above 4000rpm) etc is absolete. Infact i recall a F1 Ford engineer telling me in UK that if you want to have good power instead of blueprinting the engine he told me to drive the car RedLine from the 1st mile . Ive seen it work with the newer cars, he was correct. As nowadays we dont have bearings being .002mm larger all bearings are machine made to the correct size to the thousands of an inch. But guys i dont suggest you doing this on older cars, as bearings are not part of the assembly and will have certian parts having high friction.

Also no the engine wont overheat etc no worries at all after the reset, you can also drive normally etc. The car will run on pre-programmed maps when the cars flash memory is reset till it programs a new one. So dont worry at all!. Just run the engine at idle for about 20 secs... which will warm up the O2 sensors so it will give a correct reading to the ECM... then the ecm does its thinking

Aadix, hyundai's too have their own type of programming. They also have similar ecm's. It should work no problem. The difference in the standard and the v6 is quite a bit. First due to the different engine the car has two ckp sensors. The car will have additional sensors which a standard might not have. Hyundai's (Was in a hyundau showroom today) told me they have a few complaints on the knock sensor. It is quite dangerous for the engine when the knock sensor malfunctions. Detonation in the engine can blow a hole through a piston!. Im not well versed in Hyundai ecm's as ive never modified one. But these systems do usually have a fail safe. When an error is detected by any of the sensors the system runs on a closed loop. Running preset numbers from the ecm. Also displaying a check engine light. After the problem is rectified, a computer is used to reset DTC (Diagnostic Trouble Codes). Afterwhich the check engine light will switch off.

Cielo uses a pretty old system and does not rely much on the newer management things. The computer is pretty basic it calculates fuel mixture using the HEGO. and other basic sensors. Tweaking is possible with your ecm. But its better to do another mod than performing this. As ECM reprogramming we charge a bomb! due to the investments involved. Or if you are good at electronics. I can give you a few cheap (2 Rupee) ideas which will work pretty good.

Rehaan About the knock sensors ive heard, But the newer accent's have a better management system and should have a failsafe.

Cheers
Dom

[vishnugnair]

hey dom i dont think i can fix it myself..! maybe i should leave it aside..1

[v12]

Originally Posted by [b

Quote[/b] ]These cars ecm's even control door ajar lights!!. From example if a wire is cut to one of the rear door switches these ecm's register an error code

Hey dom, i guess this system is also present in the old Honda City. If the brake light or any lihghts conk off, a light on the instrument panel blinks [error code].

Also dom, i have one more Q. Can the ECM be infected by virus?? I mean are there any chances of a virus entering the ECM while reprogramming it??? If yes, what are the precautions taken.