Hello,

I have a GSR swap that I recently installed in my ek coupe. I got a scan tool today to check my cel and I get NO LINK on the pocket scanner. The guy I bought the swap from said the ECU was chipped. But the more and more research I am doing is showing that a P72 OBDII being chipped is rare.

Couple Questions:
What can I do to get codes from ECU? Directly - is there a harness or USB adapter I can buy?
How can I tell if it is chipped or not?

My symptoms are as follows. I have backfire after full throttle so I think it is rich. and from 2-3k is super boggy unless I am super easy on the throttle.

any help is appreciated.

Thanks
Chris

 

Im assuming one of two things are going on...

1) Are you using an OBD2 GSR ECU, or an OBD1 GSR ECU w/ jumper harness? If you're using the OBD1 ECU, you will not be able to read codes via the OBD2 DLC port. You'll have to use the SCS jumper behind the passenger floor kick panel.

OR

2) You are running an OBD2 GSR ECU, BUT it is a JDM ECU. This will also cause communication issues when using a code reader through the OBD2 DLC port. If you'd like to take a picture of the ECU, we can tell you what you've got.


As far as your drive-ability issues, lets first determine what the cause of the ECU connectivity issues and then go from there. Curious to know though - have you been having this problem the entire time since swapping in the GSR?

 

No jumper harness. It is a P72-04 from research shows an OBDII.

Here are the pictures:






Thanks for your help I appreciate it. Just wondering what I need to do to get the codes. I am assuming they are for the O2 sensors but not sure. I have no CAT so not sure where to put the O2 if that is the case. I just want to get the code and fix the CEL. also wanted to test emissions as I have to pass those things

 

1) That is a stock OBD2 ECU, not chipped
2) There is no USB or datalog port you can use other than the OBD port.
3) You will not pass emissions without a catalytic converter, CEL fixed or not.
4) Your scan tool/pocket scanner has to be configured for an OBD2 Honda.


If it is an OBD2 Honda scan tool then you should check the wiring between the OBD port and the ECU. There could be a loose wire or poor connection.

As far as your symptoms go you could;

Check the timing
Check the valve adjustment

 

Thanks for the tips.

Here is the scanner I bought.
Here is the scanner I bought.

Shows it should work with all OBDII cars.

Must be the wiring.

Can you tune the basemap on a non chipped ECU? So if the car's within range of the emissions without a cat will fail? I've read people have passed emissions with test pipes in. What kind of cat should I be looking for? Also where do the O2 sensors go? I have a after market header and don't see where they go. Thanks for the quick reply appreciate it. Am I better doing the OBDII to OBDI harness and getting a different ECU? It has I/H/E and fuel pressure regulator, cams, and cam gears. not sure if getting a tune would help or not. I'm new into this. I have always wanted too and now I am starting to get lost. but ill be ordering some koni/gc soon so hopefully the suspension will be good and already blew one b16 trans

 

Key words there are "should work"

Not saying that it won't, I'm not familiar with those scanners.

You should check the wires.

No

If your car passes the sniffer test without a cat. Kudo's to your engine builder and tuner. They built you a very clean and efficient engine.

If your inspection includes a visual, a test pipe should never pass a legit inspection. In saying that, some mechanics/refs will look under and see the test pipe and say nothing if it passes the sniffer. If it doesn't pass the sniffer they will more than likely point out the test pipe. Not what they are supposed to do but it happens.

There should be one O2 in the primary/secondary pipes on the header/downpipe. Then there should be another jsut after the catalytic converter. If you don't have a cat then you probably don't have a down stream or secondary O2 sensor installed.

Not having any O2 sensors installed could be why your CEL is on. Not to mention that the ECU is probably running on altered maps and with aftermarket I/H/E and cams it won't be running properly.

If you convert to OBD1 you will not pass an OBD scan test.

You shouldn't really be running a stock ECU with upgraded cams. Do you know what kind of cams are in there? Was the person you bought this swap from running it with the stock ECU or did he have it running at all before he sold it to you?

You need to find out what cams are in there and what is required of your car to pass emissions tests. Once you find that out you can figure out what tuning will be required to have your engine running properly and pass your emission tests.

 

There is a service connector by the ecu with 2 wires that you can jump across that will flash your check engine light.

I have used the spark plug defouler on the post cat o2 sensor with good success to eliminate the cel for not having a cat.

 

Thanks for the info. I am 90% positive the wiring is ok I just took emissions before engine swap so luckily I have two years to do it again. I may also try to register it out of our county to get around that.

My bigger concern is that its not running properly. It seems ok as I've been driving it but the sputtering between 2-3k makes be believe there is to much fuel going into it.

I do not know the exact cams I will ask and see.

Thanks for the help.

 

Take your spark plugs out and see what they look like. Spark plugs are a very reliable source for seeing how your engine is performing.

 

Is there anyway to tell what cams are in it? the guy I bought it from is not hitting me back so I am not sure if he is going too.

 

Gotta remove the camshafts to check.

 

Ok took plugs out. Not good. the fourth cylinder plug is covered in oil. So I am assuming the valve guides are no good or a bent valve.

But I did more research on my DLC not working. I am having a hard time figuring out. I traced my wiring the BLU/YEL from the DLC to the ECU and it goes into the same pinout on the P72 ECU as it did on the P2P ecu. Which I do not believe is correct. The ECM description on civic wiring diagram is KLINE(DLC) and on the Integra diagram it shows TXD/RXD. So not sure what pin I should put it in to get the DLC to read the engine codes. Here is a pic.

 

K-Line and TXD/RXD should be one in the same. If you look at the Integra wiring schematic TXD/RXD should go to the DLC as well. TXD/RXD stands for data transmit and receive. The data line should be on C8 if I'm not mistaken.

 

Check the 7.5A, #47 fuse in the under hood fuse box. Supplies power to the dlc.

 

the scanner gets power. I think the pin is in the wrong pin out.

 

Have you made any modifications the in dash wire harness?

Have you checked the back of the data link connector to ensure that all the wires are secure, clean and in the proper position?

As far as the ECU pin is concerned. I do not have an OBDII Integra specific wire diagram. However I do have an 00' OBDII Civic Si wire diagram. It shows pin C8 K-Line going to the data link connector. What does your Integra diagram show? Please do not go buy a pin out list. You need to use an electrical connections diagram to see what wire goes to the DLC. It would make this so much easier for you.

 

My integra is just from the manual i got from autozone. It just shows lines of where they connect it doesnt show what connector number they are in. Does anyone know this? Seems like it should work right? Everything i have read doesnt show anything about moving the DLC pin out. I really want to run to see what the codes are i want to get rid of this CEL staring me in the face. Thanks.

 

Does the EK have the Service check connector under the dash? I know with the OBD2A 95-97 Accords we can still jump the connector and read the flashing CEL codes.

 

Yes, ek civic also have the connector as well. It is right by the ECU.

 

Ok. I still haven't been able to resolve. but from lookin here http://www.ff-squad.com/technet/wiring.obd2a.htm I see that it is supposed to be going into c8 as it is supposed to. How could i trip the service connector what pins and then any documenation on how many flashes mean what. i have done in past on older cars but not sure about newer.

Also does anyone know if the downstream O2 is supposed to plug into cabin harness or into the engine harness of the gsr? i have two plugs for O2 it looks like on the engine harness but i still have the plug in the floor as well. Thanks for the help.

 

The self diagnostic procedure is still the same on the newer cars... it will still flash the usual Honda 2 digit CEL codes when you jumper the 2 pin service connector.

Not sure about the O2 question!

 

Copy that on the same method as the OBD1 setup. As for the oil in the plugs, is it on top of the plug as well when you remove the plug socket? Might just be a valve cover gasket around the plug hole area.

 

The oil seems to be just on the top of the plug. But got oil leaking now from somewhere as well. Not sure where to start. I think I am going to have to pass emissions soon so I need to get the O2 stuff squared away. Does anyone know which plugs to plug the O2 into on a EK GSR swap? Also for the misses, from what I have been reading it could be a distributor or ECU does that sound right? The plugs looked good to me the last time I had them out. Thanks for the help.

 

Ok I finally got time to trace wire. The one wire goes through great with 0.0 ohms the other is the SRS which gets some resistance think its going through the airbag module. Still nothing on the OBDII scanner. but the light with the service connector tripped either did 5 short or maybe 1 long and 4 short. It didn't really seem like it was that much difference but maybe a little. But I can not find anywhere what that means. the 5 codes from what I can see just means its in diagnostic mode. thinking my ECU might be fried. Still cannot figure out why I am getting the stumbling on acceleration. The best three guesses I got is distributor, ECU, or throttle body. That's like $600 worth or parts that I would rather not guess at. Has anyone experienced the stumble on acceleration before?