ESP full-off +open loop question

[expo5.0]

I wired in a temporary switch to turn the esp system full-off so that i could easily switch to dyno/race "mode". of course the abs system goes off line as well, but in any situation i should be shutting the esp all the way down i shouldn't need abs anyways (and i'm not likely to forget since it will be flashing all those lights in my face).

i'm planning to make it permanent as soon as i find some aftermarket switches that i like (or some extra benz switches).

I am trying to find a way to literally "switch" the car into full open loop as well. Under cold start the car runs open loop so if i can figure out what sensor the car is using to determine that it is cold- i will be able to wire in a resistor to emulate that and have that be switchable as well. This would allow me to truly "tune" the car using my maf scaler to a higher degree. Anyone know what tells the car it's cold (with this application in mind?)

thanks

btw a new picture-

[Section 8]

hi expo hows things....hows the car waht sort of power you tapping now...
oh and where is ya headlight lol

[expo5.0]

car still has no official numbers that mean anything-

I fixed my initial stuttering issue with a new maf- however, car is still running lean most likely and i'm not getting into the throttle (or driving t for that matter). I will be adding a lot of performance monitoring gauges, larger fuel pump etc. soon and then we will see.

headlight is a pain to take in and out- staying out until sc is up and running as i want

[Nelson Lago]

IAT (intake air temp) thats what tells the pcm to stay in open loop. But i do belive its intergrated into the maf. Plus knowing Mercedes if it doesnt see that sensor it will calculate it using many outher sensors. well good luck

[Section 8]

dude youl figure it all out...and youl have ya self a really nice AMG

[expo5.0]

for sure that's the sensor it uses?

that would be really good news and very easy to trick...

it wouldn't "not see the sensor", when the switch was flipped it would be seeing a "cold" reading from the sensor (i'd fabricate an electronic module for that- probably just a resistor is all that's needed)

[c280nz]

i am sure it doesnt use the intake air temp sensor to go into open loop at all cold or hot.
most probebly be a water temp sensor,
and i dont even think it will be going into open loop when cold,
what makes you think it does? if anything just injecting more fuel when cold from a pre determined "cold start map"

please explain to me how you come to the conclusion that it is in open loop when cold? because it is not very easy to figure that out.

and its gona be a tricky one to pull off there expo

quote: car is still running lean most likely
dude get a wideband, even a second hand ebay one is better than none then you can do alot of basic tuning by yourself without alot of expensive dyno runs.
one dyno run when the guy says nah its too lean is something you could have figured out by yourself and would probebly cost the same as the sensor.

p.s your car looks bad missin the headlight- drag style

[expo5.0]

dude- i have a wideband on the way. my wrx was totalled last week/money only coems in so fast. it's not like i'm driving it untuned etc.

I came to the conclusion that it is in open loop while cold because ALL cars are (at least in my experience and research)

don't act like i'm dumb

i have frends at the dyno place- wanted to get it checked out there initially

[c280nz]

im not acting like your dumb, i just would like more info to help figure out wat is going on,
sucks your car got totalled but lucky its only a wrx
cool you are geting a wideband will help you alot

what does ur numberplat say? just struggling to read it slntamg?

[jnolte]

teach me how to make this switch

[expo5.0]

i was drunk posting last night too, lol

[NISMOPOWERED]

1 A scanner can tell you if its in open or closed loop.

2 Many things will make it go to open loop, WOT, cold reading from the EFI temp sensor, Limpmode, ECT.

If you want it to go to open to run richer use a resister on the EFI temp sensor, If the ECU thinks its cold it wil add more fuel.

[benztec]

3 things that the car uses to go into closed loop. this goes for all obd2 cars. time, temp and o2. time is inside the me so you cant control that but the other 2 you could possibly keeping it from going into closed loop. just disabling the intake air temp so the check engine light goes on will keep it in open loop. anything that would keep the cel on will keep it in open loop.

[expo5.0]

can it be done that it goes into open loop without throwing cel using one of these methods?

any idea how quickly it will switch over?

wot doesn't seem to always change it into open loop (at least not when i had it on the dyno last, but the maf was bad then too)- THAT is why i'm considering other options.

-drew

[omeyhomey]

i heard theres a way to just disable esp but not ABS... I dunno how but supposedly if you know how to hardwire the system you can bypass ESP and keep ABS, never tried so don't quote me.

[expo5.0]

i could figure it out possibly if that's the case- I had made the assumption that both systems used the same sensors... and couldn't be run without the other.

-drew

[omeyhomey]

Originally posted by expo5.0
i could figure it out possibly if that's the case- I had made the assumption that both systems used the same sensors... and couldn't be run without the other.

-drew

thats what I thought but some said that it is possible to just deactivate the traction control system (or at least put in a true on/off switch). I will have to do more research but that may be a viable option.