hello, sorry for the title not sure how to name this.

i have a 97 dx coupe i just purchased as a new project. the check engine light is on, the diagnostic port does not connect when using a code scanner. the speedometer and the tachometer do not work.

it has a d16y8 engine although the car is a dx, i was told the wiring harness matches the y8 engine and was swapped from the same car, i am wondering how to identify the ecu and wire harness to make sure they are correct. i'd like to keep repairs as cheap as possible but understand i might need a new wiring harness and/or ecu

and input on diagnosing, or identifying would be greatly appreciated.

 

any info on the year of the engine? Because there is obd2a and obd2b, if stuff doesn't match up then stuff doesn't work. You could always find the OEM wiring harness for your car and then just wire in VTEC yourself.

 

i dont know how to determine the different obd2's i know the car is supposed to be obd2-a the car came with 2 different ecu's and two different wiring harness' i believe one set it d16y7 and one is y8

 

use the Y7 harness and wire in your VTEC, that'll be your easiest solution

 

is that the only thing that would need to be wired? i was reading about an o2 sensor possibly needing to be wired. i'll try and find more about wiring vtec, i've done it in a 92 eg before.

 

If he used a y7 harness wouldn't he also have to rewire the iacv?

 

if the y8 harness is obd2a that would be even easier as it's plug and play. we need more info to answer this can you post pics of the 2 ecu's you have . or at least the numbers on them and where the plugs go in

 

i'll try and get that information tomorrow, the iacv is 2 wire and is plugged in currently. it was either a knock sensor or the o2 sensor i was reading about.

 

I said if you used a y7 harness

 

if hes using a conversion harness and a obd1 ecu chipped it the scanner port wont work u need to flash codes with the brown or blue plug by the ecu with a paper clip or wire

 

If the speedometer and tach both don't work then it sounds like someone used a '99 - '00 harness in a '96 - '98. See the differences below.

 

p2p-a12 ecu code

and the harness appears to be a 99-00

 

safe to say the engine is probably 99-00?

is there allot involved in swapping a obd2-b engine into a obd2-a car?

 

welp problem solved.. you have the wrong engine harness. you use the obd2a engine harness on the newer motor. wiring is different between the years but the sensors stayed the same mainly

 

The ECU and wire harness are OBD2b, which is a match.

 

so plug in play with the right harness and ecu?

any idea where to find those cheap? the marketplace looks sketchy imo.

i guess i can sell my 2 sets of ecu/harness'

 

thanks for your help everyone, the thread can be marked as solved.

 

the gauge cluster wont work and the data port because the skinny green plug has diff pinouts between the two years as well. u can see that obviously from those 2 pics

 

Am I missing something? The OP says he has both an OBD2b ECU and OBD2b wire harness.

 

Yes.

You need the OBD2B cabin harness as well, using a '99 - '00 engine harness in a '96 - '98 leaves you with no "A" plug. The green plug that connects to the cabin harness is also pinned differently.

Choices are:

Find an OBD2B cabin harness

or

Find an OBD2A engine harness, ECU and distributor, this one is a lot less work.

 

Thanks

The cabin harness wasn't mentioned.

 

the distributor is different to?

 

i have a obd2-a harness that was in it originally but it doesnt have vtec and i would still need an ecu.

 

Yes, '96 - '98 uses a single large plug, '99 - '00 uses a single small plug (except '99 - '00 HXs which remained OBD2A)

You can depin the vtec wiring from the '99 - '00 harness and add it into the Y7 harness.

 

i think im going to go with the plug and play harness/ecu/distributor, thanks for all the help.