obd2a engine harness plug issues

[BlitZ]

Hi all..

I recently installed an obd2a harness for a friend's civic em1 (obd2b)..

the thing is.. the obd2a engine harness has 3 plugs that fit directly into the ECU...

whilst the obd2b engine harness had 2 plugs that went into the ECU and a 3rd from plug is from interior harness..

deliema is now i have 2 plugs that are exactly the same that plugs into the ecu on the same socket , b/c im using an obd2a engine harness and obd2b interior harness....

does thisn sound right?

[ECU-MAN]

im a bit confused

but I think you got the wrong harness

my understanding is

OBDIIa uses connector A, B, D no C connector

OBDIIb uses connector A, B, C, and no D

when looking at the ECU connectors from left to right

PK2 ECU only has two connectors A and B

its OBDII but not a or b

[BlitZ]

yeah ecu man.. your correct..

My obd2a (96-98)civic vtir engine harness comes with A,B,D plugs


but my ORIGINAL obd2b (99) civic vtir engine harness only comes with B and C (A is from the inside of the car)

since im using the obd2a in the obd2b vehciel.... i now have 2 "A" connectors..what i do?:( current car has no fuel pressure....



im a bit confused

but I think you got the wrong harness

my understanding is

OBDIIa uses connector A, B, D no C connector

OBDIIb uses connector A, B, C, and no D

when looking at the ECU connectors from left to right

PK2 ECU only has two connectors A and B

its OBDII but not a or b

[ECU-MAN]

still a bit confued

but this is what I got so far

you have a EM1 which is OBDIIb

you have a OBDIIb to OBDIIa convertion harness

you have a ?DM P30 OBDIIa B16A?

your EM1 will have 3 ecu connectors A B and a Blue C

your harness should have the 4 connectors ( 1 big molded one ) that will accept these three EM1 connectors. all in a row A,B,C but no D

then the other end of your harness will have a OBDII A, B, and D connector.

you plug the harness into the P30 OBDIIa ECU , you plug the A, B, D ( the C is blank with no pins. )

if the above is not how it works for you then you have the wrong harness.

if you have 2 A connectors make sure you plug all the EM1's ECU connectors into the OBDIIb to OBDIIa harness, then the harnness 3 connectors in the ECU.

if you OBDIIa ECU is JDM you will be fine. IF its AUDM or USDM it will have an internal immobilser and will not start the car.


BTW in my above post I thought you had a CXi. you wont have a PK2 ecu with 2 ECU connectors.

[bennjamin]

take a picture !

[BlitZ]

you have a EM1 which is OBDIIb


Correct



you have a OBDIIb to OBDIIa convertion harness

nope.. i got a complete obd2a engine harness not conversion harness



if you OBDIIa ECU is JDM you will be fine. IF its AUDM or USDM it will have an internal immobilser and will not start the car.

Running PFC - obd2a, oriingally from an integra


I have 2 A connectors.. 1 from engine harness (not a conversion harnesss).and one from inside the cabin.. dont know where thats from..

ILL POST PICs tonite.. thanks for you help so far.....

[barefootbonzai]

Yeah doesn't sound right bro. There should only be one interia plug, and it doesn't look anything like "A" plug.

[BlitZ]

Yeah doesn't sound right bro. There should only be one interia plug, and it doesn't look anything like "A" plug.

thats what i was thinking,.. there is a green interiro plug ... but then there is another "A" connector plug.. WTF...
Ill get pics later

[ECU-MAN]

cool just saw your other post,

you got it running


your post above explains alot more about what your doing :)

[BlitZ]

cool just saw your other post,

you got it running


your post above explains alot more about what your doing :)

thanks for your help ecu man..:thumbsup: