Wiring A 94 Ls Ecu To A 93 Civic Cx

[visiontcivic]

When i was connecting the harness to the ECU my CX harness has only 3 plugs, and it looks like the LS ecu has four slots for the plugs... whats that third one and do I need it? Plus how do I hookup the O2 senor, My stock one has like a 1 wires i think and the ls has like 4 wires.. Need help soon thanks

 

[pills_PMD]

what is the code on the LS ecu?

 

[vtecsir1]

you need a 4 wire o2 sensor

 

[AllMotorMonster]

Originally posted by visiontcivic@Mar 24 2003, 12:55 PM
When i was connecting the harness to the ECU my CX harness has only 3 plugs, and it looks like the LS ecu has four slots for the plugs... whats that third one and do I need it? Plus how do I hookup the O2 senor, My stock one has like a 1 wires i think and the ls has like 4 wires.. Need help soon thanks

If the LS ecu has 4 slots for plugs, you got yourself a OBD2 ecu.

You need a 92-95 OBD1 LS ecu.

OH, and yea, add 3 wires for the 02 sensor like vtecsir said.

 

[visiontcivic]

how do i hook up the 3 wires, and can i use the ecu thats obd2 on a obd 1 engine? and not use that 4th plug

 

[AllMotorMonster]

Originally posted by visiontcivic@Mar 26 2003, 09:15 PM
how do i hook up the 3 wires, and can i use the ecu thats obd2 on a obd 1 engine? and not use that 4th plug

Buy a Helms manual and check the pinouts

And

Negative on the OBD2 ecu on a OBD1 engine.


Buy a OBD1 P74/75

OR

Buy a P06 and have it chipped to P74/75 specs

 

[nism]

i have P75 OBD1 ecu on my 94 ls, and it has 4 plugs(it is rare, but it does exist)

 

[visiontcivic]

Yeah I think thats what i got, becuase mine has 4 plugs, and i didn't use the 4th one, and it still works fine... i just need to know how to hook up the O2 sensor, and the map sensor, now im drving around with the CEL but other than that its working good.

 

[posol]

Originally posted by nism@Apr 7 2003, 08:17 AM
i have P75 OBD1 ecu on my 94 ls, and it has 4 plugs(it is rare, but it does exist)

WTF?

take a pic of this rare ecu

 

[-nismo-]

do not have a picture of it right now,but I know for sure it is from 1994 jdm integra,and the stiker says it is p75, auto ecu ,and the third plug is for auto tranny wiring.And recently,I did ls/vtec swap,and I replaced this p75 with pr3-j00,and now I got cel ,and the car is idling around 2000 all the time,cant solve the problem,any ideas?

And people,sorry for my english

 

[posol]

what code are you getting? consult the articles section on page 4 for more info on pulling the codes.