got IV with VIII ecu already swapped in it. pins 20&21 are in its original place in connector. when I turn the AC on, only the main (inner) fan comes into play. should it be so ? when does AC fan turn on then ?

then swapped these pins to 32&34 accordingly (also tried in 31&32) but in this case neither fan came into play


also, wierd thing is, pins 8&22 are in their original places too (determined by colour). when swapped them over, car didn't start at all. changed back to previous state - everything's good.


any suggestions are greatly appritiated. mainly interested about AC fan issue

 

With regards to 8 and 22, you might have a 7 ecu instead of an 8 ecu. The wires arent switched in the 7 ecu.

Don't know what to say about the fans. 32 and 34 always works for me.

Pull the rom and determine exactly what you have. Maybe it's a 5,6 or 7 ECU.

 

yeah, I know about 7 ecu, that's why I opened the caseing and checked the board nubmer on it, JE331B58904A - definately 8 board

the rom is 96530706 tephra v7 there

 

Pm!

 

think I've found the culprit

opened the ecu case and saw this on the back side of the board ....




it came in someone's mind to cut and solder pins and tracks directly on the board this explains that every pin in car's loom is unswapped and sits in original places

and also this very person has forgotten to solder rad fan pin and did the main fan only ! hadn't got time to do, but think just swapping pin 20 to 32 will put everything in its place

 

installing evo8 4wire O2 and where can I join second heater wire on ecu ? would pin 25 be ok ?
also please tell which color is for which wire on evo8 O2 sensor

 

yes pin 25 is ok

oem sensor 2 black heater wires doesnt matter which you use for in pin25 and out pin 60 / blue wire pin 92 / white wire o2 signal pin 76

 

thanks todd

I'll try and join sensor&ground wires to cars original plug (near the valve cover), and then run two additional wires for heater through the firewall to the ecu pins

hope it's the correct way

 

 

what to do with wires 6&87 ?

they are SAS & Idle switch on JDM evo 4
on usdm evo8 ecu these pins are EGR & Blank

should I leave these wires in place ?

 

leave pin 87 as it is
disconnect pin 6

if you get an egr cel disable in ecu periphery

 

Hey Guys, sorry to hijack a thread, i have searched the forums, i have an evo 4 i put an evo 5 engine init as well as swapped the ECU for a evo5 ecu too. having a similar issue with the o2 sensor as there are 4 wires too. my check engine light is not coming on but between 1000 & 2000rpm the revs fluctuate, even when the car is in motion. could this be because of the heater wires on the o2 sensor not being connected? i also blanked out my EGR. not sure if that would affect anything? help please.

 

check see if the o2 sensor is working , another thing to check is tps setting at idle and last do you have a vta dump valve

 

hey todd6027, i will check on the sensor, any ideas what the reading should be on evoscan? or i can figure out a different way to check if its working, perhaps pull the one off my evo4 motor. will check the tps setting at idle. when it warms up its fine, idle drops after, to about 875 according to evoscan. but other than no change.
i still have the standard recirculating dump valve.

 

o2 sensor voltage in evoscan , engine warm idling should go up and down between 0.1 and 0.9 v
tps should around 12 to 14%