[Darkstar1999]

What is the need in resetting the ECU?
What does resetting do?

 

[Sassan]

it clear any and all information in the computer, and your car basically starts from scratch.

 

[kenshi]

it clear any and all information in the computer, and your car basically starts from scratch.

It also resets this (from the FSM):

MIXTURE RATIO SELF-LEARNING CONTROL

The mixture ratio feedback control system monitors the mixture
ratio signal transmitted from the heated oxygen sensor 1 (front).
This feedback signal is then sent to the ECM. The ECM controls
the basic mixture ratio as close to the theoretical mixture ratio as
possible. However, the basic mixture ratio is not necessarily con-trolled
as originally designed. Both manufacturing differences
(i.e., mass air flow sensor hot film) and characteristic changes
during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical
mixture ratios is monitored in this system. This is then computed
in terms of “injection pulse duration” to automatically compen-sate
for the difference between the two ratios.
“Fuel trim” refers to the feedback compensation value compared
against the basic injection duration. Fuel trim includes short
term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used
to maintain the mixture ratio at its theoretical value. The signal
from the heated oxygen sensor 1 (front) indicates whether the
mixture ratio is RICH or LEAN compared to the theoretical
value. The signal then triggers a reduction in fuel volume if the
mixture ratio is rich, and an increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out
long-term to compensate for continual deviation of the short
term fuel trim from the central value. Such deviation will occur
due to individual engine differences, wear over time and
changes in the usage environment.

 

[Sassan]

It also resets this (from the FSM):

MIXTURE RATIO SELF-LEARNING CONTROL

The mixture ratio feedback control system monitors the mixture
ratio signal transmitted from the heated oxygen sensor 1 (front).
This feedback signal is then sent to the ECM. The ECM controls
the basic mixture ratio as close to the theoretical mixture ratio as
possible. However, the basic mixture ratio is not necessarily con-trolled
as originally designed. Both manufacturing differences
(i.e., mass air flow sensor hot film) and characteristic changes
during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical
mixture ratios is monitored in this system. This is then computed
in terms of “injection pulse duration” to automatically compen-sate
for the difference between the two ratios.
“Fuel trim” refers to the feedback compensation value compared
against the basic injection duration. Fuel trim includes short
term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used
to maintain the mixture ratio at its theoretical value. The signal
from the heated oxygen sensor 1 (front) indicates whether the
mixture ratio is RICH or LEAN compared to the theoretical
value. The signal then triggers a reduction in fuel volume if the
mixture ratio is rich, and an increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out
long-term to compensate for continual deviation of the short
term fuel trim from the central value. Such deviation will occur
due to individual engine differences, wear over time and
changes in the usage environment.

yeah, I meant to put that in there too...I must have mistyped something somewhere.

 

[[email protected]]

when you put on a wai, why is it that you need to reset the ecu.. does the check engine light go on or something,, if so won't that just go away after a certain number of times that the engine clickss over and is started.... ? i just bought a cheap one from alex a few days ago and am putting it on this week end so i just want to know what to expect and how to fix it if its totally necesary....thanks

 

[kenshi]

when you put on a wai, why is it that you need to reset the ecu..

Read my above post and ask yourself this question: What happens when I install a new intake? The answer is that you'll change the way the engine sucks in air. Doing that affects the air/fuel ratio (mixture). As the above post explains, the ecu makes long and short-term adjustments to the mixture based on engine conditions, which you'll change by installing the new intake. Resetting the ecu will let it re-optimize the mixture more quickly. And the engine light will not go on as long as the intake sensors are performing properly and the ecu doesn’t detect any faults.

 

[[email protected]]

alright, thanks- now i gotta go look for that screw because i saw other 2nd gens were having problems finding it or something,,,
late

 

[Lifeofshadoze]

I just went down there to reset my ECU also. I took off the plastic piece, but i didnt find the ECU. Do i have to remove the carpeting or something?

 

[Ry]

I just went down there to reset my ECU also. I took off the plastic piece, but i didnt find the ECU. Do i have to remove the carpeting or something?

http://www.altimas.net/forum/showthread.php?&threadid=17998

There's pics of what it should look like on second gens in that thread. I think it's the same for both first and second gens.