EJ conversion wiring.. interesting find.

SuBaRiNo · Post by **SuBaRiNo** » Sat Feb 02, 2008 8:58 pm

Was doing some reasearch earlier about another thread and stumbled accross something interesting for EJ conversion wiring.

I found that EJ22 ECUs that came with an Auto gear box have a wire on them that is connected to the Economy button. On all wiring diagrams i have found this is labeled as an AT transmission wire that goes to the AT ECU. Because of this... people cutting down there harnesses simply cut this wire an isulate it.

By doing this it seams you are infact locking your ECU into Economy mode. Making the ECU run off the best Map to save fuel. As you know this is not the best mode for performance.

I did some tests on the Hatch this afternoon with this wiring and although it is extreamily difficult to notice any sort of performance gain i did notice a difference with how my Air/Fuel meter behaved.

It seams that without this wire conected, below 3/4 throttle the ECU uses the sensors to calculate its Air/fuel ratio. This makes the meter flicker from lean to rich (which is normal). Above 3/4 throttle the mixture becomes rich, as it's meant to.

With the wire connected the ECU must be using a different map and it seams under even small throttle it makes the mixture Rich. I was un-able to test this at cruising speeds to see if it would remain rich or how it will behave.

Im not sure if this is a real benefit other than using a bit more fuel but i assume if it made no real difference they never would have added the Economy button to begin with.

Anyone else played around with this.

Dave

vincentvega · Post by **vincentvega** » Sat Feb 02, 2008 10:43 pm

interesting mate

i own said auto and i dont notice much difference in power or economy mode..

It does make some difference to the shift points on theauto - i didnt know it went to the ECU

mattims · Post by **mattims** » Sat Feb 02, 2008 11:01 pm

yeah if the Ej22 ecus are anything like the B4 ones that power button changes to computer to a completely different set of maps (timing ,fuel, open loop closed loop points etc)

Gannon · Post by **Gannon** » Sun Feb 03, 2008 7:07 am

vincentvega wrote: It does make some difference to the shift points on the auto - i didnt know it went to the ECU

I agree

Power mode in autos is designed to yes, make the auto change up gears at higher revs to make better use of the power curve. This works in favour for pulling heavy loads like caravans ect.

I was under this impression too. I thought it was only the newer cars (like new libs that have SI Drive) that altered the fuel map.

Suby Wan Kenobi · Post by **Suby Wan Kenobi** » Sun Feb 03, 2008 9:47 pm

I was always of the opinion that the power economy switch was only for the shifting pattern of the auto.

SuBaRiNo · Post by **SuBaRiNo** » Sun Feb 03, 2008 10:13 pm

I too belived this.... but after some more driving with being able to turn this on and off im even more convinced. It Definatlely alters the MAP of the ecu.

Dave

Matatak · Post by **Matatak** » Sun Feb 03, 2008 11:32 pm

are u going to keep this wire from us forever

i to like many more beleived it only made the auto shift earlier. thats all it felt it did in my liberty when i drove it before the conversion and in my dads ols outback.

but u may be right i guess.

(ps. whic wire is it

)

Outback bloke · Post by **Outback bloke** » Mon Feb 04, 2008 6:52 am

It is interesting. Would also be interesting to find out what pin is in that position in the manuals. If there is an option there that isn't connected.

thesaidbin · Post by **thesaidbin** » Mon Feb 04, 2008 9:44 am

BYB-01 wrote:It is interesting. Would also be interesting to find out what pin is in that position in the manuals. If there is an option there that isn't connected.

now we talking

keep us posted of ya finds dave

SUBYDAZZ · Post by **SUBYDAZZ** » Mon Feb 04, 2008 10:10 am

According to the Gregory's manual:

The Power/Economy switch allows selection of two transmission shift modes. When Power mode is selected, the ECU delays the upshifts and the kickdown is more responsive.

At least this is for GEN 1 Libertys anyway.

The 1992 Liberty owners manual also describes that the auto transmission changes modes when the POWER or ECONOMY modes are activated. POWER mode is automatically selected by the transmission (assuming the TCU) depedning on how quickly the accelerator is depressed. This only applies when the transmission is in the D, 3 or 2 position.

I think you'll find with further testing that the fuel map won't change, but the output to the transmission from the ECU will.

98choppa · Post by **98choppa** » Mon Feb 04, 2008 6:09 pm

the auto seems to be the main thing altered,also the power drop is only felt down low,these are much more noticable settings with a turbo car(gen2 tt)

in the liberty the power switch would seem to reduce thetake-off 'punch' a fraction, in the hold' mode(snow mode?) the car has no launch punch at all, im not sure if its ecu related but it feels like the torque converter is holding things back!?

in the converted car,where does this wire hook up to to make this function happen?

Post by **Alex** » Mon Feb 04, 2008 6:19 pm

interesting. My ecu is off a manual liberty so i suppose this wire is insignificant in my case?

alex

SuBaRiNo · Post by **SuBaRiNo** » Mon Feb 04, 2008 7:03 pm

I have drawn up a pinout off the ECU showing the wire and what wire you can bridge it to to trick it out of economy mode. I will post it later.

Dave

Matatak · Post by **Matatak** » Mon Feb 04, 2008 8:01 pm

soooo was thinking today.

if u seriously think it changes the Map of the ECU.

then why dont we givethe "power" circuit voltage or wteva to turn that on.

i cant remember ever noticing a "economy" button on my Lib but i remember the power button and Hold button.

SuBaRiNo · Post by **SuBaRiNo** » Mon Feb 04, 2008 8:18 pm

MAT your are a genius. You don't need the gregories book mate...

And i don't "think" it changes the map... i know it does... i can see the readings. But i will confess i can't feel any power increase. Not to say there isn't any at all.

This post wasn't a guess... i did tests before i said anything.

Dave

Matatak · Post by **Matatak** » Mon Feb 04, 2008 8:23 pm

SuBaRiNo wrote:MAT your are a genius. You don't need the gregories book mate...

And i don't "think" it changes the map... i know it does... i can see the readings. But i will confess i can't feel any power increase. Not to say there isn't any at all.

This post wasn't a guess... i did tests before i said anything.

Dave

sarcastic im guessing

(wasnt sayin ur wrong iwht it changine the maps either)

SUBYDAZZ · Post by **SUBYDAZZ** » Tue Feb 05, 2008 11:54 am

98choppa wrote:in the liberty the power switch would seem to reduce thetake-off 'punch' a fraction, in the hold' mode(snow mode?) the car has no launch punch at all, im not sure if its ecu related but it feels like the torque converter is holding things back!?

The "HOLD" mode makes the car start in 2nd gear to reduce wheelspin in slippery conditions (ice & snow).

I think a few things might be muddying the waters here, what EJ22 year model is that ECU from Subarino? And, are you running an auto box?

Not all Libertys came with an EJ22, though I know they were still being produced in at least 1998. Some appeared to have had a power switch, and others had an "Economy" switch.

mattims · Post by **mattims** » Tue Feb 05, 2008 1:00 pm

the other possibility is that when you flick the switch it is causing an error (maybe the TCU is supposed to respond) and that is causing the car to run in safety mode (which does not rely on the o2 sensor so would stop the af ratio from flicking from lean to rich in cruise).

But i think if thats the case you should be getting a check engine light also (if you have to connected to something)

Matatak · Post by **Matatak** » Wed Feb 06, 2008 11:53 pm

SuBaRiNo wrote:I have drawn up a pinout off the ECU showing the wire and what wire you can bridge it to to trick it out of economy mode. I will post it later.

Dave

wt...later in the year.

Suby Wan Kenobi · Post by **Suby Wan Kenobi** » Thu Feb 07, 2008 2:44 pm

I have been looking over wiring and cant work out why the power switch would change the engine mapping when its primary function is to change the shift point on the auto. Not doubting your finds but maybe its as suggested forcing an error to occur or maybe the initial open throttle is given more fuel in power mode?

Keep us updated please.