Hi guys,


Since I`ve notice a small drop into the turbo boost I went to Mitsubishi dealer to check the problem.

They made a OBS check to see if there is any trouble code.

I start to think that maybe is a turbo issue because I have turbo gauges inside and my pressure was before 1,3 PSI max in WOT and now when i notice the problem I had max 0,9-1,0 max in WOT.

I know over there only one skilled mechanic and I explain him the problem.

He said that he wants to check another thing to the differential and he completed almost 100 grams of oil in differential.

I took the car for a small run and incredible but true..... turbo has returned to the initial capacity of 1,3 PSI at WOT.

Explination was that when I change the clutch or something else......with no particular reason... I loose some differential oil because I don`t have no visible oil licks.

The oil level was a little low than the normal but still not under the oil sensor limit of the differential ....so no code was on in order to read the problem.

The AYC send this command to the ECU in order to decrease the power boost for keeping the differential safe.

Likely the AYC somehow notice this oil level and send a command to ECU.

 

Is it a 6 speed?

A recent discovery is that the UK spec 6 speeds have a temp probe and if it gets to a certain temp it limits boost.

 

Yes...I have 6 speeds

I just don`t know how it happend since my lack of oil it was allmost 100grams.....not more....

Do you say that 100 grams of oil can make the difference between a certain temperature of the AYC???

Don`t know what to say........ definetly something was causing that and I don`t know how to prevent this in the future.

The only thing is to change the oil.

My fear is about the AYC ECU......and just don`t know what to check.

Since the dealer don`t have any clue about that....only with you guys I will solv this.

 

u can deactivate the AYC ECU if thats your worry (there are negative effects)

weird though, did not think the AYC could contribute to a drop in boost.......

if your AYC fluid (the one in the trunk/boot) was low you would have thrown a code though.

 

This is also my position about this

Should be a code over there but no code on

And we are talking about 100 grams of oil differential.

Maybe 100 grams less than the normal limit can make the difference......who knows.

Now everything seems normal again....and I hope it will remain like this.

Anyway it was funny to realize that the AYC can command the ECU to decrease the boost.

 

IMO, you had a boost leak and he topped up the fluid anyway.

no code means no decrease in boost.

i have my AYC disconnected and i am tuned to 24 psi.

 

Hi mate,

Look more closely with the issue that I had and I present into my post........

Some EVO`s are related with this feature and some are not.....l

The center differential it is connected to the ACD clutch pack instead of the VCU.

What they find into the OBD reader was no code on because the oil level was a little low but not under the safe level line in order to open a trouble code.

Again....can be the heat sensor who send the command to the ECU since oil sensor did`nt read a fault......?!?!?!

Yes.....ACD/AYC ECU reads several sensors that control the limited slip action of the center differential but they are working together.

Ok you can say that ACD/AYC just a Limited Slip Differential but it`s a electronic controlled LSD.

I think you know that some USDM Evos....don`t know if all of them...... don't come with the full AYC & ACD combo. US VIII and IX will not see the full AYC/ACD package.

I know that what I post here seems unbelievable ......also for me it was the same.....because I was there....

It was no leakage in boost or other issues.....

Only 100 grams of oil...... free-up the boost....

And since now I return to a stock rom version form my old tuned one....I can feel very easy the differences in boost.

Fact is that in 10 minutes between the moment of stoping the car and the driving test after they add oil.....the boost was like before....(1,2-1,3 BAR)

I don`t think that the boost leak.....like you said.....or....god knows what was the real problem.......fix by itself......without any intervention...except adding oil.... in just10 minutes....

I did`nt said that if there is a problem with the AYC/ACD........ we can`t have max boost in WOT......

I just said and I post this thread .....for some people who can encounter the same issue maybe.....and in order to avoid this....they will try also this wired thing of adding oil into differential.



Thanks....

 

Can be ....that a small leak of pressure into the AYC/ACD can send a signal to the main ECU to reduce the boost???

I know that the AYC/ACD has only some several fixed control inputs like:

4 wheel speeds
g force (lateral and longitudinal)
braking state on or off
steering angle neutral position , straight ahead and off centre position provided by 3 optical inputs generated by rotation of the steering wheel
handbrake state on or off
system pressure (hydraulic pressure state)
mode switch (gravel, snow or asphalt) software strategy witch I think is all about some special maps like maybe we have in our ECU`s

Also there is an input connection with the throttle position witch is a variable value.....and maybe this is the key factor into this problem.......

Don`t know......just my oppinion......

 

i have a JDM IX so i have AYC/ACD.

this is new to me and hard to understand - i am not doubting you.

yes - without AYC then you have no ACD and does tie into the clutch packs in the diff, hence no AYC - no LSD.

still confused though lol....

but hey at least ur getting full boost!

 

ha ha ha

for a stock rom also this can be very sensitive

it's nice anyway to feel it

also for a stock pill car

take care mate