ST165 to ST185 ECU Conversion

Mafix

New member
well if you rewire to a 185 ecu and get it to work then you can always use PnP systems like the aem!
 

Mafix

New member
so are you going to make some of the 165 harness to 185 ecu adapters...cause if not i'm gonig to have to make one. lol.
 
i have three 165 ecu's ,also one complete 165 harness and one cut near the ecu plug area(jdm swap)- my current harness is a completely custom 165 harness(by custom i mean it was built from scratch by a rally team with two quick disconnects for easier engine swaps between stages). as much as i would like to go stand alone- its probably less expensive to do a 185 ecu as there is more aftermarket support with electronics for the 185ecu. whats the chances of getting the same setup???
 

polarmoment

New member
for what it's worth, OBDI hondas use the exact same plug as the toyotas. a lot of the civic/common ecu's are hard to find, but there are some bastard child boxes that no one wants that should be pretty cheap.

the plugs are made by AMP/tyco too, so if you're doing a large volume of them you may be able to get your hands on them from the manufacturer.
 

polarmoment

New member
female receptacle is amp/tyco part # 174518-7

the male plugs are part #'s 174514-6 (16 pin), 174515-6 (22 pin), and 174516-6 (26 pin), with contacts being part #'s 173631 (large) and 173716 (small). you'll need 16 of the larger and 48 of the smaller ones.
 

allblackalltrac

New member
polarmoment":2jnhdc9m said:
female receptacle is amp/tyco part # 174518-7

the male plugs are part #'s 174514-6 (16 pin), 174515-6 (22 pin), and 174516-6 (26 pin), with contacts being part #'s 173631 (large) and 173716 (small). you'll need 16 of the larger and 48 of the smaller ones.

OMFG - BEST POST EVER!

Thank you so much for sharing that bit of information, I have spent years trying to find this.
 

All4Traction

New member
Hey guys, i havent been around for a while, i would be very interested in producing these, but... im in my last few months of graduating school and time is a limitation, i might be able to get a couple done, but once May comes along i probaly wont have access to the internet where ill be workin :(
 

DangerViking

New member
I'm about to start on installing a 185 motor into my 165 this weekend, and I am going to need to make one of these for sure :) If it's not too much trouble, do you have a wiring diagram that you used? I've read Chris' writeup on the harness conversion, and looked at the pinouts for both, but if you already have something, it'd make life soooo much easier :)
 

DangerViking

New member
I just went over everything again on the pinouts for each gen's ECU, and assuming everything else swaps over, the only things I'm unsure of are:

ST185 ISC Valve connections (RSC and RSO) to ST165 ISC Valve connections (ISC1 and ISC2)... which goes to which?

ST185 OX2 connection (Check connector, assuming for O2 sensor).. does it connect to anything?

ST185 VC connection (Sensor power source).. just hook this to switched power (like the +B connector)?

ST165 E22 connection (sensor ground).. does this go anywhere?

ST165 FPU connection (Fuel pressure VSV).. does this go anywhere?

ST165 VS Connection (Air flow meter).. should be the last one that I can't find a connection for on the 185 ECU.

Other than this stuff, is there anything else crazy that I would need to know? What did you do about the fuel pump relay and resistor, or does just swapping the connections over and using the stock 165 harness take care of this? which, if any, sensors needed to be swapped over? Did you have to swap any plugs on the engine side of the harness? Thanks again, and sorry for all the questions :) Hopefully once all this is done, I'll be putting together a writeup on how to get it all done.
 

All4Traction

New member
RSC=ISC1
RSO=ISC2
I didnt connect OX2 to anything
VC goes to VC
E22 can just be grounded
FPU is scrapped
VS goes to VS


I wish I had time to do a thorough write up and even produce these.
Next winter ill have lots of time

Its quite a simple job though, im suprized I was the first to do it.
 

DangerViking

New member
Thanks for the info :) I'll hopefully be making one of these really soon, as soon as I get all my wiring/vacuum stuff hooked up to the second gen engine, and I'll get a writeup made.
 

DangerViking

New member
polarmoment":3c7bnjys said:
female receptacle is amp/tyco part # 174518-7

the male plugs are part #'s 174514-6 (16 pin), 174515-6 (22 pin), and 174516-6 (26 pin), with contacts being part #'s 173631 (large) and 173716 (small). you'll need 16 of the larger and 48 of the smaller ones.


I was going to order everything from onlinecomponents today.. for 17361 they show:
Part Number Manufacturer Quantity On Hand
17363-1 AMP / TYCO
173631-1 AMP / TYCO 3704
173631-2 AMP / TYCO
173631-6 AMP / TYCO 18730
173631-7 AMP / TYCO

and for 173716 they show:
Part Number Manufacturer Quantity On Hand
173716-1 AMP / TYCO 11321
173716-2 AMP / TYCO


I'm just going to buy some of each of what they have in stock, just not sure exactly which part # I should get, or if it matters?
 

Qlynxer

New member
I tried ordering a plug from onlincomponents and decided not to because the minimum is 30 dollars.

Quan L
 

Cody Mamak

New member
Hey, I just read the reply to my thread and went over to this one. :wink:

Please All4Traction or someone, could write down the full list of pin corrispondency between 165 and 185 ECUs or link to some documents about this matter? :D

Also, any downside using this converter (that might save up the day for many many of us not having a 185-165 full harness to convert or some problems doing it or having a incomplete one and so on... ) so far?Any issue about having different fuse boxes or any component that is just different / works in a different way in the 2 harnesses / ECU signals ?

Anyway I want to just say that this workaround is great, proops to All4Traction :smokes:

BTW, any idea of where to find correct plugs /components would be good, since 30 dollars orders online is stupid IMHO :shoots:
 

All4Traction

New member
Qlynxer":1myzvd73 said:
Here's a link showing the pins for 165 and 185 ecus. http://www.alltrac.net/reference/
If you look at the two diagrams you'll begin to see that most of the pins on the 165 ecu are also on the 185 ecu, they're just in different places.

Good luck Quan L

Bingo, and on another thread somewhere, i explained what to do with the "extra's" that dont correspond.

Edit: :doh: I explained those above, haha.
 
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