1989 civic DX d15z1/Hf tranny

[California98Civic]

I don't think there were any 7 wire O2 sensors n 1989 or since. Time to start rechecking what has already been checked. You need the factory manual, though I guess Chilton's or Haynes's will do. I still suspect the wiring and the pinout. You now have a second known good O2 sensor in place and you still get the heated O2 code? There is an open in a wire somewhere, or a false connection. It needs careful, determined, methodical testing. I am not sure I'd trust anyone else's eyes but my own at this point--even a mechanic.

[nitebluesky]

its a d15z1 motor from a 1993 honda civic vx. The car has been converted to obd1 its no longer and obd0 from 1989. I swap this motor in three months ago and the tranny from an 91 crx hf a month ago. Anyways, Ive heard an 02 sensor OEM having 7 sensors on it. I might either pull the motor and sell it and put another D series in it. Tomorrow my buddy gets discounts on honda parts and is going to order an OEM 02 sensor and take a picture of it and see if the 02 has 7 wires. The hx and VX i heard use the same 02 sensor. Correct me if i am wrong.
My old 02 thats only 3 months old has a blue wire. The new one has a red wire. Both are 5 wire wideband. My distributor has 7 wires. *scratches head* I would think they would match up. My car ran fine over the summer when the air was hot and the ground was hot. Now that its cold and ground is cold the code 48 LAF heat sensor has came on. From what ive heard and read is that the 02 has a few ground wires on it. I somehow couldnt find a picture of an OEM 02 sensor on here at all or the web. Here ive attached some pictures of the old 02 blue wire from ebay and another one with a red wire also from ebay.

[slownugly]

If I remember correctly the harness side has 7 wires the oxygen sensor Side has 5. The sensor side plug has 7 prongs in them because there is a resistor in the connector itself. I need to confirm this tomorrow as I am in bed already. I'll send a pic tomorrow morning and then check wiring diagram when I get to work

[slownugly]

Never mind you got it. They way you have it is correct. See on the back of the sensor connector where that flat spot is? I believe the resistor is in there. There is a brand new Honda sensor on eBay right now with only 5 wires.

I hate to sound like a broken record but check the wiring again. And make sure all 7 of those wires are going where they need to. I remember when I did my swap I ran into that and got confused and I just wired it the way the diagram said and I had no problems. Later is when I found out about the resistor being in the sensor connector.

[slownugly]

Oh and don't give up!!

[nitebluesky]

with the limited amount of time i have while being in engineering school this has been put aside. School first than this and this is very annoying to me lately. I built this car since my school is 40 miles away one way and im luckly to get even 30 since my gas has just been dumping like crazy. I think i might get fed up and take it to a shop and left them figure it out. Not a regular mechanic but one that does honda swaps and conversions etc. Dealerships wouldn't touch this set up. I only can work on this car on the weekends. Just frustrating.

[slownugly]

Is the vx harness from a 93 as well?

With a schematic, multimeter, and a helper you could knock it out within a half hour on the weekend.

[California98Civic]

Originally Posted by nitebluesky

with the limited amount of time i have while being in engineering school this has been put aside. School first than this and this is very annoying to me lately. I built this car since my school is 40 miles away one way and im luckly to get even 30 since my gas has just been dumping like crazy. I think i might get fed up and take it to a shop and left them figure it out. Not a regular mechanic but one that does honda swaps and conversions etc. Dealerships wouldn't touch this set up. I only can work on this car on the weekends. Just frustrating.

That's the right priorities, man. Studies first. I know your frustration. I rely on the car I have to repair for my daily driver. I have been where you are. Hang in there. Step back a short while. Notice slowly and I are saying the same think: recheck wiring. Get a buddy, a couple beers, a multimeter, and a wiring schematic... I'll bet slowly is right that it'll take a very short time to solve now that other possibilities are eliminated.

[slownugly]

Ok here's what I got for ya

The oe wiring harness shows the o2 as having a red wire from the factory.

Now in regards to the 7 wires coming out of the o2 harness side-

Black- goes directly to a hard ground at right rear of engine. ( listed as ground h)
This is a shared ground with several other systems an is easy to test. Just check continuity between the black wire and the battery negative.

Green/white- this is also a ground but instead of a hard ground to the block or body it is supplied by the ecu from pin D22. The wire is also green/white at the ecu and supplies ground for the egr sensor, tps, iat, and coolant temp. Also the same test as the black wire. These two grounds can be tested without a helper within minutes. The rest of the wires go easy with a helper.

Yellow/black- this is the heater control that is the same spot at the ecm for all 5th gen civics (save for maybe the cx which is only one wire o2) in a vx harness this changes color to orange and black right before the ecu. Check for continuity from the 7 wire harness plug to the ecu pin A6

White- goes to pin D3 and is marked as LABEL. It is white at the plug but by the time it gets to the ecu it changes color to blue/yellow on a vx harness. Also check for continuity.

Orange/blue- goes to pin D14 at the ecu and stays the same color in the vx harness. It's labeled as IP+

Orange- goes to pin D16 at the ecu. It changes color to blue/green at the ecu in a vx harness. It is labeled as IP-VS-

White/blue- goes to pin D8 at the ecu. It stays the same color to the ecu in a vx harness. It is labeled as VS+

[nitebluesky]

well hopefully ill figure it out this weekend. Could i possibly hardwire it to the ecm? the 02 sensor. Making the wires really long and just pin it to my ecm? I found this drawing today. i think this will be simple and useful. Here are some pictures and let me know what you think.