Hey guys, I just threw in a JDM B18C with a P73-003 ECU. into my 96 Coupe. I turn it on and after i take off the check engine light comes on. Well I tried to take it to get autozone to get the code but it turned out that since it's a JDM, the diagnostics plug in comp. cant even establish a connection. That's all good, I've got no problem doing it the old school way by counting the number of flashes when jumpering the connetion, but my question is are these codes valid for my ECU or are they based on USDM hondas only. Here's a link I found through the search.


https://honda-tech.com/zerothread/1901557

BTW: Nice write up pdiggitydogg!!!

Thanks for the help

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by j_scobar &raquo;</TD></TR><TR><TD CLASS="quote">Hey guys, I just threw in a JDM B18C with a P73-003 ECU. into my 96 Coupe. I turn it on and after i take off the check engine light comes on. Well I tried to take it to get autozone to get the code but it turned out that since it's a JDM, the diagnostics plug in comp. cant even establish a connection. That's all good, I've got no problem doing it the old school way by counting the number of flashes when jumpering the connetion, but my question is are these codes valid for my ECU or are they based on USDM hondas only. Here's a link I found through the search.


https://honda-tech.com/zerothread/1901557

BTW: Nice write up pdiggitydogg!!!

Thanks for the help</TD></TR></TABLE>

what do you mean the plug is comp because it's jdm? you mean compatible? it's not compatible? your car is obd2, there should a plug on the driverside. that has nothing to do with it being jdm or usdm.

as for the codes from pdiggitydog, yes they are the same whether it's usdm or jdm.

 

Ok, thanks. I can use the write up to figure out what code is causing the CEL to com on.

As for the diagnostic connector on the drivers side, I tried two different autozones to see if the guys could plug up and give me a reading but both times the were not able to establish a connection with the ECU. I bought the motor from H Motors Online, complete JDM swap out with the ECU and when I called them Steve told me that that because it's a JDM ECU, I wouldn't be able to connect via the diagnostic port and I would have to check the code by counting the flashes. It made since to me so I didn't question it, the guy runs a good business and I have no complanits what's so ever about the motor he gave me. To tell you the truth I was impressed.


Modified by j_scobar at 9:49 AM 3/27/2008

 

does anyone have some input on this?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by j_scobar &raquo;</TD></TR><TR><TD CLASS="quote">Ok, thanks. I can use the write up to figure out what code is causing the CEL to com on.

As for the diagnostic connector on the drivers side, I tried two different autozones to see if the guys could plug up and give me a reading but both times the were not able to establish a connection with the ECU. I bought the motor from H Motors Online, complete JDM swap out with the ECU and when I called them Steve told me that that because it's a JDM ECU, I wouldn't be able to connect via the diagnostic port and I would have to check the code by counting the flashes. It made since to me so I didn't question it, the guy runs a good business and I have no complanits what's so ever about the motor he gave me. To tell you the truth I was impressed.


Modified by j_scobar at 9:49 AM 3/27/2008</TD></TR></TABLE>
yeah steve is cool. I also bought a jdm b18c from him like 2 weeks ago and barely installed it like 3 days ago. I have error codes too.. I have code 41 which is heated 02 sensor, and code 17 which is Vehicle Speed Sensor (Vss) so my gauge isnt working. what car are you swapping it into?

 

Truth..

USDM machines that plug into obd2 cars and read information from the ECU (ie: autozone, advanced auto parts, inspection stations) cannot read information stored on a JDM ECU, they are only capable of reading information from USDM ECUS. Thus if you wanna run your codes on a JDM ECU you have to do it the old fashioned way by jumping the harness and yes the OBD2 codes are the same for both markets.

 

Perfect, that's exactly the information that I was looking for.

As for 562daybid's question, I bought the B18 swap for my 96 coupe. It was first a show car with no go but now it's somthing seriouse. I've been working on this for some time now. The car is shaved all the way around, no door handles, no washer fluid squirters, no exterior antenna, and no gas door. The fuel pipe was relocated to the trunk. It's also got coil overs all the way around an acord rear end and a molded body kit with a fresh blood red paint job. Now that it's complete I'll be posting some pics in my garage soon. What about, hows your project coming?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by j_scobar &raquo;</TD></TR><TR><TD CLASS="quote">Perfect, that's exactly the information that I was looking for.

What about, hows your project coming? </TD></TR></TABLE>
not so good.. found out that the alternator doesnt work and it drained the hell out of my battery.. Now i gotta go to autozone and get a new alternator and charge my battery. I figured that Ill take off the engine harness and redo the wiring all over again and this time double check everything.. hopefully this will correct my cel.. luckily for you your coupe harness is plug and play.. I wish I would have bought an ex harness instead hahah

 

the obd 1 and obd 2 codes have always been the same in my multiple swaps. jdm and usdm. Has never been diferent in my incounters.

 

So you lack to give the most important info... what codes? And yes JDM ECU's cannot be read by usdm obd2 scanners.

 

well originally that was the purpose of the thread, so I could figure out what code I could match the CEL flashes to and it they were the same between USDM and JDM. I haven't driven the car in a couple of days but I'll check it today and take it out for a spin. Thanks for all the help guys, I'll post the code on this thread just to follow up.

 

Funny thing about JDM P73 computers is that they have the OBD2 style plugs, but run an OBD1 program.

They only read one o2 sensor, don't look for evap system, no CKF sensor, no catalyst readings, etc. etc.

...this has a lot to do with why scan tools don't communicate with them too.

Anyways jump the check plug over with a looped wire/paper clip and tell us the codes!

 

Alright guys, I was finally able to get the codes. It said that there's a problem with:


#14 - IAC (EVAC) - Idle air Control Valve
#41 - Primary Oxygen Sensor heater

I'll search around to see what I can find on them but if any of you have anyting on them it would be appreciated.

Thanx

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by j_scobar &raquo;</TD></TR><TR><TD CLASS="quote">#14 - IAC (EVAC) - Idle air Control Valve</TD></TR></TABLE>

Most of the time this is thrown if the IACV is bad itself. This is an electronic sensor located on the back of the intake manifold. It's directly in the middle and has a black cylinder piece hanging on it with a two wire round plug on it.

I say "most" of the time because things such as a dirty throttle body, backed out/dirty mixture screw can also cause this code too. A simple check is if the idle is acting up and you unplug the IACV and the idle smooths back out then you need to replace the IACV, or at the very least try to clean it out and reinstall it.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">#41 - Primary Oxygen Sensor heater</TD></TR></TABLE>

Replace the primary oxygen sensor, or the wiring to it could be jacked up. this sensor is lcated in the bottom of the header just before the catalytic convertor where it bolts to the header.

 

Alright, I think I've got it figured out finally.

#14 - IAC (EVAC) - Idle air Control Valve - was thrown because I adjusted the Idle when doing the swap and it just needed to be reset.


#41 - Primary Oxygen Sensor heater - I think I have a wiring problem. I replaced the sensor and still the code would not clear. I ohmed checked the wires to verify their location and according to the link below and it looks like I must have the O2 sensor hooked up to the secondary O2 sensor connection. The think is, my swap came with all of the sensors already installed on the motor but I had to use my original harness to hook them all up and modify the ones that were not in the original harness (i.e. Knock sensor). The O2 sensor that came with the B18C motor only had one O2 sensor and had the standard green, white and two black wires attached to it, it so I just took the connector that went to that same type sensor from the old motor and took it to the new O2 sensor. Now it appears that I should have somehow modified the connector that went to the sensor that was mounted to the one on the manifold and not the one on after the cat. It didn't occur to me at the time since the connectors were the same and I thought the sensor on the old motor that mounts on the manifold was for the map sensor and the one mounted on the lower end (after the cat) was the O2 sensor.

In a nut shell, I've got a Code 41 popping up and when I pinned it out Pin6 of the A connector, it goes to the connector that originally hooked up to the sensor that mounted on the manifold and not the one that I hooked it up to (the one that mounted to the bottom after the cat). Can someone tell me what I need to do to fix this. I was thinking of taking my old sensor form the old motor and just plugging it in and mounting it in place of the new O2 sensor but I'm not sure if it will work.


http://technet.ff-squad.com/wiring.obd2a.htm

 

Now that I looked over the ECU Pin out link, I'm a little confused which one pin I should be checking because it says that connector:

A pin 6 - is for the PO2SHTC Primary O2 Sensor Heater Control

and

D Pin 7 - is for Primary Heated O2, Sensor -1

Which one should I my O2 Sensor be connected to???

 

I figured out why I'm throwing the CEL code 41. When I used the harness from my old motor to do the swap, the old motor was equiped with a primary and a secondary O2 sensor, the Primary was a 5-wire and the secondary was a 4-wire. my new B18C came equiped with a 4-wire O2 sensor so without thinking, when I was changing over the harness i wired the secondary sensor plug to the B18's o2 sensor, this is why I'm getting a code 41, because the sensor is going to the secondary sensor spot in the ECU. What can I do to fix this??? I've been searching on how to rewire the 5-wire connection that I have for the primary to make it work for the 4-wire sensor that came with the swap, but I haven't fownd anything. Any ideal what I can do?